manualshive.com logo in svg

LeCroy DDA 7 Zi series, Руководство оператора

Поделиться
Скачать
LeCroy DDA 7 Zi series Скачать руководство пользователя страница 365

Operator's Manual 

WP700Zi-OM-E-RevA 

364

Note:

 Other math choices in the 

Operator1

 menu include 

Boxcar

,

ERES

, and 

interpolation

. The boxcar "filter" 

is a simple average taken over a user-specified number of points (the "length"). 

6. Touch 

inside 

the 

FIR/IIR

 field and select finite or infinite response filterFIR (non-recursive) filters require a 

limited number of multiplications, additions, and memory locations. On the other hand, IIR (recursive) 
filters, which are dependent on previous input or output values, in theory require an infinite number of each. 
.

7. 

Whether you selected FIR or IIR, touch inside the 

Filter Kind

 field and select a filtering operation. Some 

choices are not available for IIR. 

8. 

If you selected FIR, touch inside the 

Type

 field and choose an FIR filter type. Then touch inside the 

Taps

[The number of coefficients. The suggested number of taps is a minimal suggestion: using even more 

taps can give a more desirable response. Using less than the suggested  number of taps will not meet the 
requested specifications.]  data entry field and enter a value, using the pop-up numeric keypad. 
Alternatively, you can touch the 

Auto Length

 checkbox; the 

Taps

 field is grayed out and the scope 

calculates the optimum number of coefficients. 

If you selected IIR, touch inside the 

Type

 field and choose an IIR filter type. Then touch inside the 

Stages

data entry field and enter a value, using the pop-up numeric keypad. Alternatively, you can touch the 

Auto 

Length

 checkbox; the 

Stages

 field is grayed out and the scope calculates the optimum number of stages. 

9. Touch 

the 

Frequencies

 tab. 

10.  Depending on the class (FIR/IIR) and kind of filter you selected, and whether or not Auto Length is 

enabled, you can change the cutoff frequencies, transition width (edge width), stop band attenuation, and 
pass band ripple. 

Custom Filters 

Custom Filter Setup 

If the standard filters provided with DFP2 are not sufficient for your needs, you can create filters with virtually any 
characteristic, up to 2000 taps. 

The required custom filter can be designed with a digital filter design or math package such as MATLAB or 
Mathcad. The filter coefficients can then be loaded into the scope from an ASCII file. The file consists of numbers 
separated by spaces, tabs, or carriage returns. 

Note:

 Do not use commas as separators. 

For a custom IIR filter there needs to be a multiple of 6.  Each stage consists of 3 numbers for the numerator 
polynomial followed by 3 numbers for the denominator polynomial.  They are in the order a b c where the 
polynomial is of the form: a + b * z

-1

 + c * z

-2

.

Example 1: Creating an FIR Filter Coefficient File Using Mathcad 

N := 200   i := 0..N 

sinx(x) := sin(x)/x 

Содержание DDA 7 Zi series

Страница 1: ...Operator s Manual WavePro SDA and DDA 7 Zi Series Oscilloscopes ...

Страница 2: ... L R R H HUD RU D D ...

Страница 3: ...or c for any damage or malfunction caused by the use of non LeCroy supplies Furthermore LeCroy shall not be obligated to service a product that has been modified or integrated where the modification or integration increases the task duration or difficulty of servicing the oscilloscope Spare and replacement parts and repairs all have a 90 day warranty The oscilloscope s firmware has been thoroughly...

Страница 4: ...s 28 Spectrum Analyzer 29 Running the Spectrum Analyzer 29 TriggerScan 30 Training TriggerScan 31 Starting TriggerScan 32 Saving TriggerScan Setups 32 Front Panel 33 Detaching and Attaching the Front Panel 34 Side Panel 35 Back Panel 36 External Monitor 37 Dual Channel Acquisition 39 Combining Channels 39 Hardware and Software Controls 39 Front Panel Controls 39 Front Panel Groupings 41 Miscellane...

Страница 5: ... 56 Source View 56 Level Markers 56 Scan Overlay 57 Scan Histogram 58 Zoom View 59 Edge Mode 59 Non monotonic Mode 61 Runt Mode 62 Measurement Mode 63 Scan Filters 64 Filter Wizard 64 Filter Methods 65 Auxiliary Output Signals 66 Auxiliary Output Setup 66 Customization Overview 67 Solutions 68 Examples 68 What is Excel 70 What is MATLAB 71 What is VBS 71 What Can You Do with a Customized Scope 72 ...

Страница 6: ...s 89 Default Parameter Function Script 91 Hints and Tips for VBScripting 91 Errors 92 Error Handling 93 Speed of Execution 94 Scripting Ideas 94 Example Waveform Script 94 Example Parameter Script 95 Debugging Scripts 95 Calling MATLAB from the Scope 95 Selecting a Waveform Function Call 96 MATLAB Waveform Control Panel 97 MATLAB Waveform Function Editor 97 MATLAB Example Waveform Plot 99 Selectin...

Страница 7: ...stence Trace Range 114 Persistence Sigma 115 Histogram Theory of Operation 115 DSO Process 116 Parameter Buffer 116 Capture of Parameter Events 116 Histogram Parameters XMAP and JTA2 Options 117 Histogram Peaks 117 Binning and Measurement Accuracy 118 Full Width at Half Maximum 118 Full Width at xx Maximum 119 Histogram Amplitude 120 Histogram Root Mean Square 121 Histogram Top 121 Maximum Populat...

Страница 8: ... Resampling to Deskew 141 Deskewing 141 Rescaling and Assigning Units 141 Rescaling Setup 142 Averaging Waveforms 142 Summed vs Continuous Averaging 142 Setting Up Continuous Averaging 143 Setting Up Summed Averaging 143 Enhanced Resolution 143 How the Instrument Enhances Resolution 144 Setting Up Enhanced Resolution ERES 145 Waveform Copy 146 Waveform Sparser 146 Waveform Sparser Setup 146 Interp...

Страница 9: ... Math Functions 161 Overview of Parameters 161 Turning On Parameters 161 Quick Access to Parameter Setup Dialogs 161 Parameter Setup 162 Parameter Status 164 Status Symbols 164 Statistics 166 Measure Modes 166 Standard Vertical Parameters 167 Standard Horizontal Parameters 167 Selecting Measure Modes 167 Parameter Math 167 Logarithmic Parameters 167 Excluded Parameters 168 Parameter Script Paramet...

Страница 10: ...Sampling Rates 200 Roll Mode 201 WaveStream Mode 201 Adjusting Trace Intensity 202 Saving and Recalling Scope Settings 202 Saving Scope Settings 202 Recalling Scope Settings 202 Recalling Default Settings 203 Saving and Recalling Waveforms 203 Saving Waveforms 203 Recalling Waveforms 205 Disk Utilities 205 Deleting a Single File 205 Deleting All Files in a Folder 205 Creating a Folder 206 Introduc...

Страница 11: ... SPI Address Setup 224 SPI Data Setup 225 SPI Frame Length Setup 227 SPI Ack Setup 228 Overview of Serial Bus Activity 228 Capturing Long Pre Trigger Time 228 Saving Data 229 Storing Triggers 229 I2 C and SPI Specifications 233 Timebase Setup and Control 234 Setting up additional timebase setup and controls 234 Autosetup 235 Real Time SMART Memory 235 Setting Up Real Time SMART Memory 235 External...

Страница 12: ...er Works 251 Glitch Trigger Setup 251 Interval Trigger 252 How Interval Triggers Work 252 Interval Trigger Setup 254 Dropout Trigger 255 How Dropout Trigger Works 255 Dropout Trigger Setup 255 Runt Trigger 256 Runt Trigger Setup 256 Slew Rate 257 Slew Rate Trigger Setup 258 Trigger Setup Considerations 259 Trigger Modes 259 Determining Trigger Level Slope Source and Coupling 259 Trigger Source 260...

Страница 13: ... Optimizing Performance 269 Setting an Offset Control 269 Setting a Delay Control 269 Configuring E mail Settings 269 Acquisition Status 270 Service 270 Show Windows Desktop 270 Touch Screen Calibration 270 Adjusting Sensitivity and Position 271 Adjusting Sensitivity 271 Adjusting the Waveform s Position 271 Coupling 271 Overload Protection 271 Setting Coupling 271 Probe Attenuation 271 Setting up...

Страница 14: ...etup Dialog 281 Setting Binning and Histogram Scale 282 Displaying Trends 282 To Configure a Trend 283 Trend Calculation 283 Parameter Buffer 284 Capture of Parameter Events 284 How to Read Trends 284 View Modes 284 Configuration Options 285 Configuration Menus 286 Setting Levels 287 SETTING nT 289 Maximizing Performance 289 Pit or Space Identification 289 nT Pit Space Categorization 290 Beginning...

Страница 15: ... Options 304 PASYM PIT ASYMMETRY 305 Description 305 Display Options 305 PBASE PIT BASE 306 Display Options 306 PMAX PIT MAXIMUM 307 Description 307 Display Options 308 PMIDL PIT MIDDLE LEVEL 308 Description 308 Display Options 309 PMIN PIT MINIMUM 310 Description 310 Display Options 310 PMODA PIT MODULATION AMPLITUDE 311 Description 311 Display Options 311 PNUM PIT NUMBER 312 Description 312 Disp...

Страница 16: ...mented Waveforms 331 Histogram Peaks 331 Example 332 Binning and Measurement Accuracy 332 DVD Processing Model 332 DVD RAM 332 Filtering 333 Slicer 334 Notes on ODATA Math Function 334 Equalized 334 Operational Notes 335 Leveled 336 Sliced 336 Extract CLK 337 How the Starting VCO Frequency Phase Are Determined 340 Introduction to 8B 10B 341 Description of Encoding and Decoding 341 Running Disparit...

Страница 17: ...tup 363 DFP Filter Setup 363 Custom Filters 364 Custom Filter Setup 364 Example 1 Creating an FIR Filter Coefficient File Using Mathcad 364 Example 2 Creating an IIR Filter Coefficient File Using Mathcad 366 Multirate Filters 368 Description 368 Specifications 368 ET PMT Overview 369 Compatibility 369 Probing 370 Operation 370 Selecting a Standard 370 Test Setup 370 Adding Measurements to a Mask T...

Страница 18: ... Buffer 389 Parameter Events Capture 389 Zoom Traces and Segmented Waveforms 390 SDA Overview 391 Serial Data Analyzer Standard and Optional Capabilities 391 Table of Standard Masks Included with Option SDM 393 Jitter Wizard 393 SDA Basic Setup 395 PLL Setup 396 Summary 398 Mask Test 398 Eye Setup 398 Mask Margin 400 Testing 400 Bit Error Rate 400 Jitter Setup 401 Jitter Measurements 403 Pj Breakd...

Страница 19: ...g Rj and Dj Two Methods 426 Effective Random and Deterministic Jitter 427 Direct Measurement of Deterministic Jitter 427 Comparing Models 428 Bit Error Rate 429 Bit Error Map 429 Vertical Noise Compensation 430 Introduction 430 Signal Slew Rate and How Vertical Noise Converts to Jitter 431 The Relative Impact of Noise on Jitter Quadratic Addition of Noise 431 How the Measurement System Noise Is Su...

Страница 20: ... 448 DDA Specifications 448 Additional DDA Triggers 448 Disk Drive Measurement Package DDM2 449 Automated DDA Measurements 449 Advanced DDA Analysis 450 Drive Analysis Overview 450 Obstacles that Can be Overcome using the DDA s Channel Analysis 450 What Channel Analysis Provides 450 Channel Emulation 451 With or Without Reference 451 Stop On SAM 452 Analog Compare 452 Measure s Drive Parameters 45...

Страница 21: ...sing Channel Emulation with Reference 469 Using Analog Compare 469 Notes on Using Head Analog Compare 470 Local Feature Concepts 471 Overview 471 Local Feature Parameters 474 Disk Standard Parameters 481 Disk PRML Parameters 485 Correlation Theory of Operation 485 Notes 489 Noise Parameters 490 PRML Channel Emulation 492 Why PRML 492 Principle of Equalization 493 Resampling ADC 495 Finite Impulse ...

Страница 22: ...set Only Calibration 512 Deskew Only 512 The Advanced Menu 513 Rise Time Skew Correction 513 Deskew All or Common Skew 513 Common Mode Voltage Selection 513 Advanced Probe Calibration 513 Deskew Theory of Operation 514 Deskew Risetime Adjustment Theory 515 DC Calibration Theory 516 Differential and Single ended Probe Basics 517 WavePro Specifications 518 Technical Support 525 Safety Requirements 5...

Страница 23: ...ories available for your product Reference We ve set aside this Reference section to contain contact information for various LeCroy offices the left this section Here we cover items like the Specification Technical Support contact information and Safety Requirements Support When your product is delivered verify that all items on the packing list or invoice copy have been shipped to you Contact you...

Страница 24: ... On the Channelx Setup dialog touch to place a check mark in the Cable De Embedding checkbox A Cable De Embedding tab will be displayed 3 Touch the Cable De Embedding tab 4 Touch inside the Cable Specified by data entry field and select Attenuation Constants if you want to specify your cable characteristics by entering the two attenuation constants of the loss model for the cable provided by the c...

Страница 25: ...sion of the acquisition timebase Sequence mode offers a number of unique capabilities x You can acquire up to four channels simultaneously x You can minimize dead time between trigger events for consecutive segments x You can view time stamps for acquisitions x You can zoom segments or used them as input to math functions x You can combine sequence mode with an advanced trigger to isolate a rare e...

Страница 26: ...ng up Sequence Mode you define the number of fixed size segments acquired in single shot mode see the instrument specifications for the limits The oscilloscope uses the sequence timebase setting to determine the capture duration of each segment Along with this setting the oscilloscope uses the number of segments maximum segment length and total available memory to determine the actual number of sa...

Страница 27: ...ts field is 100 5 Touch the Enable Timeout checkbox 6 Touch inside the Timeout data entry field and enter a timeout value using the slider bar at the bottom of the window Click the keypad button on the slider bar to enter a value using the pop up numeric keypad Note Use the sequence mode timeout to automatically interrupt the sequence acquisition if the timeout value is exceeded without a valid tr...

Страница 28: ...oll through the segments using ZOOM front panel position knob Figure 3 3 Sample Zoom of Segments in Sequence Mode 1 Touch the front panel Quickzoom button 2 Turn the ZOOM front panel position knob to scroll through the segments 3 To vary the degree of zoom touch the newly created Zx trace label The setup dialog for the zoom Z1 to Z4 opens It shows the current horizontal and vertical zoom factors 4...

Страница 29: ...elect the Segment button from the pop up menu 4 In the dialog on the right touch the Select tab 5 Touch inside the First Selected data entry field and use the slider bat at the bottom of the window to select the first segment you want to display Click the keypad button on the slider bar to enter a value using the pop up numeric keypad Note In Persistence mode the segments are automatically overlai...

Страница 30: ...cilloscope automatically configures the acquisition and FFT controls to obtain the desired spectrum view Figure 3 5 Sample dialog and display for the Spectrum Analyzer Running the Spectrum Analyzer You can run the Spectrum Analyzer by touching Analysis Spectrum Analyzer from the menu bar When you run the Spectrum Analyzer you set up controls in the Spectrum Analyzer dialog from left to right inclu...

Страница 31: ...cy 7 Show Peaks lets you label and tabulate peaks When Show Peaks is checked the significant peaks are marked with a frequency and gain stamp and a table listing the peaks ordered by amplitude from highest to lowest is displayed This is very useful in identifying harmonics or peaks that may be hidden due to poor resolution TriggerScan TriggerScan is a debugging tool that helps you quickly find rar...

Страница 32: ...want to change the trigger types or if you change the channel or signal 1 Touch Trigger Trigger Setup from the menu bar 2 On the Trigger dialog click the TriggerScan tab 3 Touch inside the Source data entry field and select a channel as the source for the training 4 Touch the Trainer button 5 On the TriggerScan Trainer Setup window choose the types of triggers the Trainer should use to train the s...

Страница 33: ...y changes to the Trigger List touch Start Scan The oscilloscope automatically sequences through all the trigger setups PLEASE NOTE THE FOLLOWING x You can tune the dwell time that the scope will wait before loading the next trigger setup using the Dwell Time data entry field x If you have Persistence display mode enabled all trigger events are recorded on the display Refer to the Persistence Setup...

Страница 34: ...Number and Description Number and Description 1 Power Button 2 Channel Row LED Indicator 3 Channel Inputs 4 Auxiliary Input and Output 5 Volume Control and Mute Button 6 Ground Connector 7 Speaker 8 Fast Edge Recovered Clock and Data Outputs 9 USB Ports 10 Detachable Front Panel Remote Control 11 Release Switch for Front Panel Remote Control ...

Страница 35: ...ever to the left and pulling at the right Attach the front panel by inserting the lower part first sliding the detachment lever to the left and then pushing the top in place Front Panel as a Remote Control While detached the front panel can then act as a remote control Just plug and play connect it to the oscilloscope using a USB A to USB Mini B cable ...

Страница 36: ...in the table Number and Description Number and Description Number and Description 1 LBUS LeCroy Bus 2 Mouse 3 Keyboard 4 USB Ports 5 External VGA Monitor 6 Ethernet Port 7 Line In 8 Speakers 9 Microphone 10 PCI Expansion Slots for DVI for standard display hardware LSIB and other options LeCroy External Display WPZi EXTDISP 15 option Note Consult your system administrator when connecting to an inte...

Страница 37: ... correspond with descriptions in the table Number and Description Number and Description Number and Description 1 External Clock Input Grounded EMI Shield required when port is not in use 2 External Clock Output 3 Removable Hard Drive 4 DVD CD R Drive 5 Power Switch 6 DC Power Plug ...

Страница 38: ...into the DVI and DC 12 connections on the PCI slot located on the side of the oscilloscope Connect your USB plug where applicable to an available port also on the side of the instrument Note To connect a standard VGA monitor connect to the VGA Port 2 Turn on the oscilloscope let the instrument boot and then touch Display Display Setup from the menu bar 3 Touch the Monitor tab and then the Enable E...

Страница 39: ...Operator s Manual WP700Zi OM E RevA 38 The following picture shows a WavePro 700Zi with the LeCroy external monitor attached optional WPZi EXTDISP15 ...

Страница 40: ...e maximized to 40GS s using two channel combinations except for channels 1 and 2 or channels 3 and 4 which always yield 20 GS s Use best practice by choosing channel 1 or 2 for your first input and channel 3 or 4 for the second Refer to Acquisition Modes in the specifications for maximum sample rates Combining Channels Procedure Set up channel combinations on the interface as follows 1 Touch Timeb...

Страница 41: ...Operator s Manual WP700Zi OM E RevA 40 The detachable WavePro Zi front panel ...

Страница 42: ...changes When you turn the knob if WaveStream is OFF changes the Intensity setting Corresponds with the screen menu selection Display Display Setup Trigger Front Panel Controls x Level Press to toggle between 50 trigger level and the previous level setting Turn to change the trigger threshold level This level is indicated on the Trigger label x Trigger Indicates the trigger status as READY and TRIG...

Страница 43: ...Vertical front panel controls correspond with screen menu selection Vertical Channel Setup x Channels Press a Channel 1 4 front panel button to turn the channel on or off When a Channel 1 4 front panel button is lit the Vertical Offset and Volts Div knobs are active for that channel only x Offset Press to toggle between a zero vertical offset value and the previous vertical offset value for the se...

Страница 44: ...an Front Panel Controls Note WaveScan front panel controls correspond with screen menu selection Analysis WaveScan x Scroll If WaveScan is On turn to scroll through the table of WaveScan filtered events If WaveScan is Off turn to adjust the selected data entry field x On Off Press to toggle between WaveScan On and Off This is the same as checking Enable in the WaveScan dialog When you turn WaveSca...

Страница 45: ...ilities Setup Hardcopy dialog Press the Create Notebook Entry button on the flyout menu to create a new lab notebook entry using the Enter Notebook Info window Press the PRINT front panel button twice to perform the last selection from the Print flyout menu the default is to print the screen image x Touch Screen Press to toggle the touch screen on and off x Clear Sweeps Press to clear data from mu...

Страница 46: ... For example the Save Setup function is referenced as File Save Setup The Quick Access Toolbar The Quick Access toolbar is located on the right side of the menu bar You can use these toolbar buttons to quickly access trigger functions x Auto Press to turn on Auto Trigger mode which triggers the oscilloscope after a time out even if the trigger conditions are not met x Normal Press to turn on Norma...

Страница 47: ...he value slider to set the field to a specific value Click the Default button on the slider bar to set the field to the default value Click the keypad button on the slider bar to set the value using the pop up numeric keypad x Flyout Menu The Print and Auto Setup front panel buttons open flyout menus For more information on these menus go to the Front Panel Groupings topic Universal ProBus ProLink...

Страница 48: ... control for a wide range of probes such as high impedance passive probes high impedance active probes current probes high voltage probes differential probes ProBus also includes sense rings for detecting passive probes All scopes with bandwidths over 4 GHz except the WavePro 740Zi and760Zi use 50 inputs and provide 1 M impedance by means of external adapters The following figure shows a typical c...

Страница 49: ...le Each of the interfaces provide power to the probe An I2 C interface allows communication with the probe which permits probe recognition and interaction This adds to the flexibility of the system as the scope can sense and control each probe Probe Interface ProBus Bandwidth ProLink Bandwidth 50 3 5 GHz 4 6 GHz 1 M 500 MHz NA Table 3 1 Probe interface characteristics The WavePro 740Zi and 760 Zi ...

Страница 50: ... to BNC adapter optional Figure 3 9 BMA to SMA Adapter 1 and BMA to BNC Adapter 2 Figure 3 10 BMA Female Connector 1 ProLink BMA to SMA Adapter Installed 2 and ProLink BMA to BNC Adapter Installed 3 Note When connecting an active probe to the instrument be sure to use a ProLink BMA to BNC adapter item 3 in the figure Do not plug the probe directly into the front panel connector item 1 without an a...

Страница 51: ...ents Trigger Enabled can be used as a gating function to trigger another instrument when the scope is ready Pass Fail allows you to set a pulse duration from 1 ms to 500 ms generates a pulse when pass fail testing is active and conditions are met Aux Output Off turns off the auxiliary output signal Auxiliary Output Setup 1 Touch Utilities Utilities Setup from the menu bar 2 Touch the Aux Output ta...

Страница 52: ...ny or All waveforms fit the criteria set by the comparison condition Setups are conveniently shown in the Summary box of the Qx dialog as follows Mask Tests Mask testing can be done using an existing mask or by using a mask created from your actual waveform with vertical and horizontal tolerances that you define Existing masks can be loaded from a floppy disk or from a network You can set your mas...

Страница 53: ...r failing a test 4 Touch the Summary View checkbox to enable a line of text showing a concise status of the last waveform and keeping a running count of how many sweeps have passed 5 Touch inside the Pass If field and select a boolean condition from the choices shown 6 If you want to set up the test to end after a finite number of sweeps touch the Stop Test checkbox Then touch inside the After dat...

Страница 54: ...elect a math operator from the pop up menu 7 Touch inside the Limit field and enter a value using the pop up numeric keypad The value entered acquires the dimensions corresponding to the parameters being tested For example if you are testing a time parameter the unit is seconds If you chose either WithinDeltaPct or WithinDeltaAbs from the Condition menu you also have the choice of setting the limi...

Страница 55: ...e Source1 field and select a source from the pop up menu 4 Touch inside the Condition field in the main dialog and select Mask Test 5 From the Test portion of the dialog make a selection in the Test is True when group of buttons This selection means for example that if you select All In the test is False when a single waveform falls outside the mask 6 From the Show Markers section of the dialog ch...

Страница 56: ...ically when unusual events are found stop the acquisition emit an audible beep output a pulse print the screen save the waveform or create a LabNotebook entry Signal Views WaveScan provides distinct views of your signal x Source view highlights all occurrences of edges that meet your criteria x Scan Overlay not available in WaveSurfer Xs scopes places all captured edges one on top of the other in ...

Страница 57: ...an is enabled the instrument reverts to Real time sampling mode Source View The top trace on the screen is the source channel math memory trace This trace shows all captured edges and highlights those that fit your search criteria For example in this figure we are searching for slow rising edges that fall outside a time window In this acquisition WaveScan has located eleven edges that fit the sear...

Страница 58: ...l the settings in the Display Persistence setup dialog and vice versa In the following acquisition we have scanned for rise times greater than 1 4 ns WaveScan has located six edges that meet this criteria one of which is greater than 2 ns This slowest edge which appears in the persistence display has been selected for zooming from the table Note that it is also highlighted in the source view top g...

Страница 59: ...a delta of 50 ps are accumulated in the histogram Another feature of WaveScan is that you can select a single bin of the histogram for analysis by touching or clicking it A confirmation pop up button then appears After Find Feature is confirmed only the single bin of the histogram remains and information about the contents of the bin is displayed in the Filter Method area You can recall the origin...

Страница 60: ...ed to vary the magnification and position of the zoomed trace Or you can use the on screen In Outbuttons In Zoom View you can also apply further processing store or apply a descriptive label to the zoom trace Edge Mode This search mode locates all edges in an acquisition and presents them time stamped in a table You can select positive negative or both edges When the acquisition is stopped scan fi...

Страница 61: ...Operator s Manual WP700Zi OM E RevA 60 As with other search modes a trigger action can be set for Edge mode also ...

Страница 62: ...l are presented in a table and highlighted in the source trace The value displayed in the table is the difference of the max and min of the non monotonicity This can be confirmed with cursors The hysteresis value is used to eliminate noise A non monotonicity is detected only when its amplitude is greater than the hysteresis Therefore when setting a hysteresis level set a value that is greater than...

Страница 63: ...nate noise In the case of negative going runt pulses the value displayed in the table is the difference delta of the high level of the signal and the runt amplitude i e where the runt bottoms out This can be confirmed by placing cursors on the runt pulse and reading the delta Y value in the trace labels In the case of positive going runt pulses the value displayed in the table is the absolute valu...

Страница 64: ...ou can apply other filters to the acquisition or make different parameter measurements on it For example in this acquisition a Rise time 10 90 parameter measurement is applied to fast edges during acquisition We are interested only in edges with a rise time slower than 1 ns Therefore the Greater Than filter method is selected with a value of 1 ns four edges pass during acquisition ...

Страница 65: ...decide how anomalous the features located should be by using the Filter Wizard to select the average value as the limit to search for rarest events or to apply statistical criteria Filter Wizard You can decide how anomalous the features searched or scanned for should be by using the average value as the limit by searching for rarest events or by applying statistical criteria 1 3 or 5 sigma ...

Страница 66: ...d as the filter limit and delta are calculated automatically Filter Methods While the Filter Wizard provides a quick way to apply filtering criteria automatically the Filter Method menu and related fields let you manually set up filtering criteria And unlike the Filter Wizard selections which are restricted to absolute deltas the Filter Method menu also offers deltas as percentages ...

Страница 67: ...ut signal Auxiliary Output Setup 1 Touch Utilities Utilities Setup from the menu bar 2 Touch the Aux Output tab 3 If you want a 1 kHz 1 V square wave touch the corresponding button 4 If you want a specialized output touch one of the buttons under Use Auxiliary Output For 5 Touch inside the Amplitude data entry field and enter a value using the pop up numeric keypad If you want a TTL level signal t...

Страница 68: ...lf If a VBScript processor decides to access via automation results other than those supplied to its inputs the scope s dependency algorithm cannot be used Therefore the results accessed may not be coherent they may be from a previous acquisition or worse could cause an infinite computation loop 3 Reconfiguring Math or Measurements Reconfiguring adding or removing Math and or Measurements from wit...

Страница 69: ...al scale from linear to non linear You don t have to use all the data from the input waveforms you can select data from one or more segments which need not be aligned in the two input waveforms Examples Example 1 Simple math functions using VBScript WaveOut is the waveform being returned to the instrument F1 in this case WaveIn is the input waveform C1 in this case You can see that the F1 result i...

Страница 70: ...mpleTime Amplitude 0 15 Amplitude of real data For K 0 To LastPoint newDataArray K Amplitude Sin Omega K Next OutResult DataArray True newDataArray Data in volts OutResult DataArray is the waveform returned to the scope and displayed on the scope as the F2 waveform Example 4 Touch here Example 4 is a measurement of DVI Digital Video Interface Data Clock skew jitter measurement using a VBScript to ...

Страница 71: ... manner Of course you will need to load Excel Mathcad or MATLAB in the scope VBScript does not require any additional software to take advantage of the capability You can think of these functions as subroutines of the instrument s main software which take in waveform data and other variables like vertical scale and offset and horizontal scale and offset These functions then return a waveform or a ...

Страница 72: ...e experience in any programming language The VBS processing function can collect a number of useful variables from the scope including waveform data and useful variables such as volts per division and time per division The output from a script can be a waveform or a parameter and you can choose your own values for variables such as volts per division The idea of a VBS function is that you start wi...

Страница 73: ...rtunities You may for example be using transducers If so you can change the units of your waveforms and write N newtons J joules and so on and you can introduce scaling factors If the transducers are non linear you can correct for that too You can also transform horizontal scales and vertical scales by manipulating the data Logarithmic scales in amplitude and frequency are often required Squaring ...

Страница 74: ... one call to Excel can use two separate waveforms as input PLEASE NOTE THE FOLLOWING x Excel has a calculation algorithm of 64 000 points 32 000 if you have created a chart in Excel Therefore make sure that your acquisition has less than this number of points if you are going to use an Excel calculation x To use this capability you must have the LeCroy XMAP software option and Excel loaded in your...

Страница 75: ... Chart Adds charts of your waveforms to Excel You can go into Excel and create as many charts as you want Organizing Excel Sheets The Cells tab allows you to organize your Excel chart When placing the components in the sheet be careful to avoid over writing needed information especially when you are using multiple input waveforms As depicted here the instrument panel has been pasted over the Excel...

Страница 76: ...riptors The next figure explains the meanings of the descriptors for each trace Multiple Inputs and Outputs If you invoke two or more instrument parameter functions or waveform functions that call Excel you will find that they all refer to the same spreadsheet by default Thus your spreadsheet can use the data from several waveforms and you can derive many different combinations of output parameter...

Страница 77: ... In this example we use Excel to invert or negate a waveform The first figure shows a part of the screen The upper trace is the original signal The lower is the result from Excel The dialog is the one that controls the location of the data in the Excel worksheet ...

Страница 78: ...e been set to start at row 2 allowing space for a title in row 1 Columns D E and F contain the headers for the three waveforms These are the set of numbers that provide the description of the scope settings such as vertical scale and offset and number of samples In this figure the panel has been pasted onto the Excel sheet for comparison ...

Страница 79: ...Operator s Manual WP700Zi OM E RevA 78 To get the output values in column C we set C2 A2 and copy this formula down the column This is the only action needed in Excel and can be seen in the next figure ...

Страница 80: ... The lower trace F1 is the result calculated in Excel and displayed on the screen The input data is in columns A and B though by default only a single input column is used and the output is in column C All have been set to start at row 2 which allows for a header in row 1 To create this waveform you would simply do the following 1 Ensure that your acquisition has no more than 64 kpts the Excel cal...

Страница 81: ...ormula for cell C2 is A2 copied for the entire column as shown here 5 Retrigger the scope if it is not currently triggering 6 Return to the program Note that the only action that was needed in Excel was to create the formula in column C for each data point in column A The instrument automatically opens Excel puts the waveform data in the correct columns and returns the calculated data back to the ...

Страница 82: ...tically and view the data there Simply press the Add Chart button in the instrument s Excel dialog and a chart of the input top chart and Excel calculated output bottom chart will be automatically created in the spreadsheet The chart will be updated automatically as the scope is triggered ...

Страница 83: ...where TC1 has negligible effect This was done using Function F1 which is not a part of the measurement process For the actual measurement Parameter P1 was set up as an Excel call In Excel the selected portion of the trace was converted to logarithms and the Excel function SLOPE was used as shown here Here we see the input data in column B with a time scale in A created using the contents of cell F...

Страница 84: ...sure that successive acquisitions produced different data Script F1 generates pulses with widths that are multiples of a set clock period F2 generates one pulse in the first half of the time window and one pulse in the second half Both pulses are constrained to coincide with the clock pulses of F1 F1 and F2 are used here only as simulations and are not part of the measurement process which only us...

Страница 85: ...10 B9 A 4 1 C9 C9 This was copied down the column Column D the output column is simply A C The output was defined as cell H3 The required mean in cell H3 is given by SUM D10 D509 SUM C10 C509 for a 500 point waveform Requires files Setup GatedParameterExcel lss Function F1 RandomPulses22Apr txt Function F2 RandomGate22Apr txt Parameter P1 GatedMean xls Correlation Excel Waveform Function This exam...

Страница 86: ...ateExcel22Apr lss Function F1 NoisySine22Apr txt Function F2 NoisySine22Apr txt Function F3 Correlate22Apr xls Multiple Traces on One Grid This example shows how you can place multiple traces in one picture with only two operations in an Excel sheet Depicted below is an example from an Excel spreadsheet Here is an original instrument trace ...

Страница 87: ... the simple expression B374 0 02 comprises several components The original instrument trace is in column B and the plot is required to start at cell B134 The traces repeat at intervals of 250 cells Let us call this interval R If we require a horizontal displacement D then in cell CN we write B N R D In this example D is 10 Finally we may want a vertical displacement V and we write B N R D V In thi...

Страница 88: ...nly as a simulator of signals Instrument setup LaserStartup25Apr lss Function F1 LaserStartupApr25 txt Function F2 LaserStartupPulses xls No offset LaserStartupPulses2 xls Vertical offset LaserStartupPulses3 xls Vertical and horizontal offset Using a Surface Plot ...

Страница 89: ...input traces InResult DataArray always refers to input trace 1 These remarks hold for any script that you write Example Waveform Function Script Square of a Waveform Example script to produce a waveform This example calculates the square of the input waveform OutResult Samples InResult Samples Visible trace length 1 Note that a trace of nominal length 1000 comprises data numbered from 0 to 1001 Th...

Страница 90: ...767 The value of InResult Samples is the total number of data in a trace It is two more than the nominal value given on the screen The first point DataArray 0 coincides with the left edge of the screen apart from the wobble caused by the trigger to sample clock difference If the trace length is nominally 500 the right edge of the screen coincides with DataArray 500 which is the 501st point The las...

Страница 91: ... be used as shown in the default scripts and in the example scripts you cannot refer directly to individual elements of these arrays You have to use your own arrays in this example unscaledData and newDataArray You are not allowed to write statements like the following Y InResult DataArray 17 OutResult DataArray 257 Z Some parts of the default script must not be changed because they are a part of ...

Страница 92: ...ot allowed to write OutResult ValueArray 0 MeanParameter InResult DataArray and OutResult DataArray are only to be used as shown in the default scripts and in the example scripts You cannot refer to or modify any individual element in these arrays Hints and Tips for VBScripting x Set the trigger to Single or Stopped if you need to do a lot of editing it is faster x Before starting a script remove ...

Страница 93: ... 32768 x You can highlight a section of a trace by making the points alternately too high and too low by a suitable amount Providing the memory length is not too short the compaction algorithm will give the effect of a thicker trace x The lengths of the output trace and the input trace need not be the same You can even make the output trace longer than the input trace but you will need to unzoom i...

Страница 94: ...ceptions You must be aware of all possibilities at all points in your program and you must either be certain that errors will not occur or you must take action to ensure that they do not Examples Function Description Sqr You cannot take the square root of a negative number Log You cannot take the log of zero or of a negative number A B You cannot divide by zero Array You cannot use an index outsid...

Страница 95: ...To Total XK X K If XK OldXK Then Y Cos XK Sin XK Sqr XK OldXK XK End If Next VBS runs slower than the internal calculations because the scripts are interpreted This could be serious for calculations where many operations are needed on each sample such as convolution correlation and long digital filters Scripting Ideas What can we do in a VBS script that we cannot do with the normal instrument func...

Страница 96: ... for these three variants of basic is slightly different Calling MATLAB from the Scope Note Load MATLAB version 6 5 just as you would on any PC Once it is loaded open MATLAB from the desktop then close it again before you attempt to open it from the instrument application This is to update the registry MATLAB can be directly called from the instrument in two ways Calling MATLAB Description Result ...

Страница 97: ...ction Call The MATLAB Waveform functions are selected from the Select Math Operator menu Please note that once you have clicked on MATLAB Wave there will be a slight pause before MATLAB starts Figure 4 6 Source 1 and Source 2 are the waveforms that MATLAB will use ...

Страница 98: ...nd Scale to make your output fit the grid or use the text boxes to choose a scale MATLAB Waveform Function Editor By touching Edit Code you can reach the MATLAB Editor where you will see the default waveform function If you are familiar with MATLAB you might prefer to launch MATLAB and create a MATLAB function that performs your task Your program in the instrument could then be a one line call of ...

Страница 99: ...l produce a visible MATLAB Response From this panel you can save your code load a previous code and edit your function A powerful feature of MATLAB is that you can refer to an entire waveform as a vector The two input waveforms are WformIn1 and WformIn2 while the output is WformOut You can also refer to individual samples such as WformIn1 34 and sequences of samples such as WformIn 55 89 You can w...

Страница 100: ...WavePro 7Zi 99 WP700Zi OM E RevA MATLAB Example Waveform Plot If you touch the MATLAB Plot checkbox you will see a MATLAB plot like this one ...

Страница 101: ...B parameter call in Select Measurement menu MATLAB Parameter Control Panel Once you have invoked a MATLAB parameter call a mini dialog to the right of the main dialog will appear You can touch the MATLAB Plot checkbox if you want to see a plot in MATLAB as well as getting a result in the instrument ...

Страница 102: ...esult would be shown in the MATLAB Response pane for an amplitude of 0 15 volt You can load an existing MATLAB program using the Load Code button and you can save the current program using the Save Code button If you are familiar with MATLAB you might prefer to launch MATLAB and create a MATLAB function that performs your task Your program in the instrument could then be a one line call of your MA...

Страница 103: ...0Zi OM E RevA 102 MATLAB Example Parameter Panel The next example calculates the ratio of the number of data points that are above a given level to the number of points below the level in this case one half of the amplitude ...

Страница 104: ...ePro 7Zi 103 WP700Zi OM E RevA Further Examples of MATLAB Waveform Functions Negate the input signal Square the input signal Create pulses from a sinusoid Create pulses at the zero crossings of the signal ...

Страница 105: ...Create a MATLAB function using any text editor and save it as a MATLAB m file by giving it a name of the form Filename m Call the function using the MATLAB math editor or the MATLAB parameter editor as appropriate A simple example is shown below function out negatewf wf1 NEGATEWF changes the sign of all the data out wf1 ...

Страница 106: ...p Note Not all grid styles are available on all instruments 1 Touch Display Display Setup on the menu bar 2 Touch one of the Grid combination buttons Note Autogrid automatically adds or deletes grids as you select more or fewer waveforms to display ...

Страница 107: ... change the value and enter a value from 0 to 100 using the slider bar at the bottom of the window Click the keypad button on the slider bar to enter a value using the pop up numeric keypad Note Access the Monitor tab for external monitor display settings Refer to the External Monitor topic for more details Sequence Mode Display Note Sequence mode is not available on all instruments To set up a Se...

Страница 108: ...lly stacked grids These side by side grids are labeled Custom in the Display dialog Included in the choices are a 3 grid display single dual and quad displays Custom grids offer views of your waveform that are contracted horizontally and less vertically Zooming Waveforms You can magnify a selected region of a waveform using the Zoom function You can display up to four Zoom Z1 Z4 and eight Math Zoo...

Страница 109: ... Channelx Setup OR Touch the channel trace label for a displayed channel 2 Touch the Zoom button at the bottom of the Cx Vertical Adjust dialog A zoom trace one of Z1 to Z4 will be created of the selected channel 3 To vary the degree of zoom touch the newly created Zx trace label The setup dialog for the zoom Z1 to Z4 opens It shows the current horizontal and vertical zoom factors 4 If you want to...

Страница 110: ...rag a rectangle around any part of an input channel waveform math trace or memory trace The Zoom Z1 to Z4 dialog opens Note If you have enclosed a combination of channel and math or memory traces in the rectangle a pop up Rectangle Zoom Wizard will appear Touch a Zoom button Z1 to Z4 2 To turn off the zoom traces touch the Undo button at the top right corner of the screen OR Uncheck the Trace On c...

Страница 111: ...1 Touch Display Persistence Setup on the menu bar 2 Touch the Persistence On checkbox If you want to set up persistence for Follow these steps all input channels at once 1 Touch the All Locked button 2 Touch one of the mode buttons 3 Touch the Show last trace checkbox if you want the last trace displayed 4 Touch inside the Saturation data entry field and enter a whole number integer using the slid...

Страница 112: ...lt settings touch the Reset All button 3 Dimensional Persistence Not Available in All Scopes By selecting 3d you can create a topographical view of your waveform from a selection of shadings textures and hues The advantage of the topographical view is that areas of highest and lowest intensity are shown as peaks and valleys in addition to color or brightness The shape of the peaks pointed or flat ...

Страница 113: ... window Click the keypad button on the slider bar to enter a value using the pop up numeric keypad 3 Touch inside the Persistence time data entry field and make a selection from the pop up menu 4 Under 3D settings touch inside the Quality field and select an image quality from the pop up menu wire frame solid or shaded 5 Touch the MonoChrome checkbox if you prefer a single color representation 6 F...

Страница 114: ...Measure Measure Setup on the menu bar 2 Touch the My Measure button 3 Touch one of tabs P1 through Px 4 Touch inside the Source1 field and select an input waveform from the Select Source window 5 Touch inside the Measure field and select a parameter from the Select Measurement window 6 Touch the Histogram button at the bottom of the dialog 7 Touch a math trace in which to place the resulting histo...

Страница 115: ...ntal or My Measure 2 Touch the Histicons checkbox to display thumbnail histograms below the selected parameters Note For measurements set up in My Measure you can quickly display an enlarged histogram of a thumbnail histogram by touching the Histicon you want to enlarge The enlarged histogram will appear superimposed on the trace it describes This does not apply to Std Vertical or Std Horizontal m...

Страница 116: ... V 50 bins or 0 1 V bin Events falling into the first bin would then be between 1 5 V and 1 6 V While the next bin would capture all events between 1 6 V and 1 7 V and so on After a process of several thousand events the bar graph of the count for each bin its histogram provides a good understanding of the distribution of values Histograms generally use the x axis to show a bin s sub range value a...

Страница 117: ...d the scope will use the parameter buffer values to redraw the histogram with either the last N or 5 000 values acquired whichever is the lesser The parameter buffer thereby allows histograms to be redisplayed using an acquired set of values and settings that produce a distribution shape with the most useful information In many cases the optimal range is not readily apparent So the scope has a pow...

Страница 118: ...equal halves hist min value of the lowest left most populated bin in a histogram hist rms rms value of data in histogram hist sdev standard deviation of values in a histogram hist top histogram top or rightmost of two largest peaks max populate population of most populated bin in histogram mode data value of most populated bin in histogram percentile data value in histogram for which specified x o...

Страница 119: ...to determine peaks The oscilloscope s 5 000 parameter buffer is very effective for determining the optimal number of bins to be used An optimal bin number is one where the change in parameter values is insignificant and the histogram distribution does not have a jagged appearance With this buffer a histogram can be dynamically redisplayed as the number of bins is modified by the user In addition d...

Страница 120: ... First the highest population peak is identified and the height of its highest bin population determined see the pks description Next the bin populations to the right and left are found until a bin on each side is found to have a population of less than xx of that of the highest bin A line is calculated on each side from the center point of the first bin below the 50 population to that of the adja...

Страница 121: ...L voltages where hampl would indicate the difference between the binary 1 and 0 voltage values Description The values at the center line dividing the population of peak in half of the two highest peaks are determined see pks parameter description The value of the leftmost of the two peaks is the histogram base see hbase While that of the rightmost is the histogram top see htop The parameter is the...

Страница 122: ...hrms Example Using the histogram shown here the value for hrms is hrms 2 87 Histogram Top hist top Histogram Top Definition The value of the rightmost of the two most populated peaks in a histogram This parameter is useful for waveforms with two primary parameter values such as TTL voltages where htop would indicate the binary 1 voltage value Description The two highest histogram peaks are determi...

Страница 123: ...cription Each bin between the parameter cursors is examined for its count The highest count is returned as maxp Example Here maxp is 14 Mode mode Mode Definition The value of the highest population bin in a histogram Description Each bin between the parameter cursors is examined for its population count The leftmost bin with the highest count found is selected Its center value is returned as mode ...

Страница 124: ... of its range is found and returned as pctl Example The total population of a histogram is 100 The histogram range is divided into 20 bins and xx is set to 25 The population sum at the sixth bin from the left is 22 The population of the seventh is 9 and its sub range is 6 1 to 6 4 V The ratio of counts needed for 25 population to total bin population is 3 counts needed 9 counts 1 3 The value for p...

Страница 125: ...e Scanning goes on over the remainder of the range to identify additional peaks Additional peaks within a fiftieth of the range of the populated part of a bin from a previous peak are ignored NOTE If the number of bins is set too high a histogram may have many small gaps This increases sigma and thereby T2 In extreme cases it can prevent determination of a peak even if one appears to be present to...

Страница 126: ...population of this histogram is 9 X Coordinate of xxth Peak xapk X Coordinate of xxth Peak Definition Returns the value of the xxth peak that is the largest by area in a histogram Description First the peaks in a histogram are determined and ranked in order of total area for a discussion on how peaks are identified see the description for the pks parameter The center of the nth ranked peak the poi...

Страница 127: ...is easy to perform using the following instructions After the recovery procedure is done you must activate Windows either by Internet connection to Microsoft s Web site or by telephone Have your Windows Product Key number located on the rear of the oscilloscope handy during Widows reactivation Note The recovery process produces a replica of the operating system and oscilloscope application softwar...

Страница 128: ... 4 As soon as the LeCroy logo appears on the screen press and hold down the F4 key until the recovery software logo appears momentarily 5 Then the cME console End User License Agreement is displayed Read the agreement and click Accept ...

Страница 129: ...Operator s Manual WP700Zi OM E RevA 128 6 The Phoenix cME Console main page is displayed Click Click here to start recover 7 The FirstWare Recover splash screen is displayed momentarily ...

Страница 130: ...nd is not an indication of any malfunctioning of the recovery process 9 After the recovery is completed the X Stream software installer screen appears Click Next to continue 10 When the X Stream installation is completed reboot the oscilloscope as follows Now you must activate Windows by Internet connection to Microsoft s Web site or by telephone When activating have the Windows Product Key number...

Страница 131: ...or 10 seconds then turning the power on again Removable Hard Drive Not available for all scope models the removable hard drive option replaces the standard internal hard drive with a removable hard drive that is installed at the rear of the scope in the slot normally occupied by the CD ROM drive The kit includes two hard drives which can be used interchangeably It also includes a USB CD ROM for lo...

Страница 132: ...can choose which notebook to use for your entries and label the notebook by project or user If the scope is shared among several users for example or used for different projects the data can be kept separately Similarly hardcopy reports can be stored in different folders Note If your external monitor is connected the LabNotebook automatically opens on the external monitor Preferences You should se...

Страница 133: ...ebook Entry 1 Touch File Create Notebook Entry on the menu bar A dialog box is displayed in which to enter a title and comments for the entry By default the entry is titled with the current date and time 2 Touch inside the Title field and enter a title using the pop up keyboard Then touch inside the Description field and enter a description if desired and touch Close 3 The notebook entry will disp...

Страница 134: ... The arrow tool enables you to draw lines with arrowheads for callouts You can rotate these lines through 360 degrees and drag them to any location on the screen The text tool enables you to enter text callouts on your report When you touch this tool a dialog box opens in which to enter text by means of a pop up keyboard After you touch Close your text will appear on the display as a draggable obj...

Страница 135: ... that color If you want to erase a drawing object touch it to select it then touch Erase Selected Touch Erase All to erase all drawn objects and text Touch Undo to discard the last object drawn The Move Toolbar button enables you to place the toolbar anywhere on the screen Touch the button a second time to return it to its original fixed location Touch Done when you are finished annotating the not...

Страница 136: ... b Histogram data Histograms internally have a 32 bit resolution but when stored into a trace file and recalled during flashback they are clipped to 16 bits c Floating point waveforms Certain math operations result in the creation of floating point waveforms with much higher resolution than can be stored in a 16 bit waveform file This extra resolution will not be preserved when traces are recalled...

Страница 137: ...uch the Close button at the right of the dialog Locating a Notebook Entry A search filter is provided to help you locate the notebook entry you want to make a report of You can search by date or keyword 1 Touch the Filter button A search dialog box opens 2 Touch inside the Day Month and Year fields and enter a date OR Touch inside the Keyword field and enter a keyword or phrase 3 Touch Find Now On...

Страница 138: ...reports 3 Touch the Browse button next to Template to navigate to an existing report format that you want to use Or touch inside the Template field and enter the name and path to the template using the pop up keyboard Otherwise touch the Use Default checkbox to use LeCroy s format 4 To use a logo other that the one provided which indicates the scope that produced the report browse to the bit map f...

Страница 139: ...s to a Folder You can save notebook entries to a folder other than the default 1 Touch the tab bearing the name of the notebook entry 2 Touch the Save Data to button In the Save Data To window select the location where you want to save the data 3 Touch the Zip checkbox if you want to compress the data before archiving Managing the Database You can begin a new database for your notebook entries at ...

Страница 140: ...integral of the averaged difference between Channels 1 and 2 Any trace and function can be chained to another trace and function For example you could make Trace F1 an average of Channel 1 Trace F2 an FFT of F1 and Trace F3 a zoom of F2 Note Math traces F5 F8 are available only if you have loaded software option package XMATH or XMAP on WaveMaster or WavePro scopes but are standard on Disk Drive A...

Страница 141: ... you want to perform just one math function on the trace or touch the Dual function button to perform math on math 7 Touch the Graph button then touch inside the Graph with field to select a graph mode The Graph modes are as follows Mode Description Histogram of the values of a parameter Track of each value of a parameter Trend of the values of a parameter over time Both Track and Trend are tools ...

Страница 142: ...ns category 6 In the dialog on the right touch the Deskew tab 7 Touch inside the Delay by data entry field and type in a time value using the pop up keypad Rescaling and Assigning Units This feature allows you to apply a multiplication factor a and additive constant b to your waveform aX b You can do it in the unit of your choice depending on the type of application Allowable unit abbreviations an...

Страница 143: ... Vertical Adjust dialog under Pre Processing and from the math function menu Summed Averaging Summed Averaging is the repeated addition with equal weight of successive source waveform records If a stable trigger is available the resulting average has a random noise component lower than that of a single shot record Whenever the maximum number of sweeps is reached the averaging process stops An even...

Страница 144: ...ator1 field and select Average from the Select Math Operator menu 5 Touch the Average tab in the dialog to the right of the Fx dialog touch the Continuous button 6 Touch inside the Sweeps data entry field and enter a value using the pop up keypad The valid range is 1 to 1 000 000 sweeps Setting Up Summed Averaging 1 Touch Math Math Setup on the menu bar 2 Select a function tab from F1 through Fx T...

Страница 145: ...vement The opposite may be true if the noise is mostly at lower frequencies SNR improvement due to the removal of coherent noise signals feed through of clock signals for example is determined by the fall of the dominant frequency components of the signal in the passband This is easily ascertained using spectral analysis The filters have a precisely constant zero phase response This has two benefi...

Страница 146: ... may be slightly attenuated Perform the filtering on finite record lengths Data will be lost at the start and end of the waveform the trace will be slightly shorter after filtering The number of samples lost is exactly equal to the length of the impulse response of the filter used between 2 and 117 samples Normally this loss just 0 2 of a 50 000 point trace is not noticed However you might filter ...

Страница 147: ...be entered for any sparsing factor equals Sparsing Factor 1 Waveform Sparser Setup 1 Touch Math Math setup on the menu bar 2 Touch the tab for the function F1 to Fx The number of math traces available depends on the software options loaded on your scope See specifications you want to assign the Sparse operation to 3 Touch inside the Source1 field and select an input waveform 4 Touch inside the Ope...

Страница 148: ...ed RF or on oscillators phase locked loops etc x Studying instantaneous power x Studying envelopes of amplitude modulated signals with variable bandwidth Only two of the result types are rescalable Frequency FM and Phase PM since the magnitudes of these projections cannot be known beforehand All of the other results are scaled on the vertical scale of the original digitized carrier waveform There ...

Страница 149: ...tant the number of filter taps increases as sampling rate increases Fast Wave Port Introduction Fast Wave Port is a processing function for the LeCroy X Stream family of digital oscilloscopes that enables you to insert your own custom processing algorithm written in the C C language into the DSO s processing stream Fast Wave Port maximizes data throughput from the acquisition system to your proces...

Страница 150: ...uch inside the Source1 field and select a signal source from the pop up menu The source can be a channel waveform math or memory trace or a parameter 4 Touch inside the Operator1 field and select FastWavePort from the Custom menu 5 In the right hand mini dialog touch the Fast Wave Port tab 6 Touch inside the Timeout field and enter a suitable value ...

Страница 151: ...GNU C Compiler GCC for example E Click OK 5 Open the Command Prompt window Start Programs Accessories Command Prompt and compile your application 6 Run your application Fast Wave Port Operational Notes Once FastWavePort is selected the right hand dialog shows the current settings The first of these is critical and indicates the base name of the memory window and the two events which are global wit...

Страница 152: ...uity in the filled data Since the data at the end of the record is filled data it is advisable to select a weighting window other than rectangular to minimize the effect of the fill on the resulting spectrum the trace display 8 Touch the Suppress DC checkbox if you want to make the DC bin go to zero Otherwise leave it unchecked 9 Touch inside the Output type field and make a selection from the pop...

Страница 153: ...ervation window produces a distorted spectrum The most common distortions can be traced to insufficient sampling edge discontinuities windowing or the picket fence effect Because the FFT acts like a bank of band pass filters centered at multiples of the frequency resolution components that are not exact multiples of that frequency will fall within two consecutive filters This results in an attenua...

Страница 154: ... This window provides excellent amplitude accuracy with moderate reduction of leakage but with reduced frequency resolution Blackman Harris It reduces the leakage to a minimum but with reduced frequency resolution FFT Window Filter Parameters Window Type Highest Side Lobe dB Scallop Loss dB ENBW bins Coherent Gain dB Rectangular 13 3 92 1 0 0 0 von Hann 32 1 42 1 5 6 02 Hamming 43 1 78 1 37 5 35 F...

Страница 155: ...n is symmetric around the Nyquist frequency that is Rn RN n while the imaginary part is asymmetric that is In IN n The energy of the signal at a frequency n is distributed equally between the first and the second halves of the spectrum the energy at frequency 0 is completely contained in the 0 term The first half of the spectrum Re Im from 0 to the Nyquist frequency is kept for further processing ...

Страница 156: ...gain of a filter corresponding to each window function is 1 0 0 dB for a rectangular window and less than 1 0 for other windows It defines the loss of signal energy due to the multiplication by the window function This loss is compensated for in the oscilloscope The following table lists the values for the implemented windows Window Frequency Domain Parameters Window Type Highest Side Lobe dB Scal...

Страница 157: ...e reduced when one of the available window functions is applied The best reduction is provided by the Blackman Harris and Flattop windows However this reduction is offset by a broadening of the main lobe of the filter Number of Points TheFFT is computed over the number of points Transform Size whose upper bounds are the source number of points and by the maximum number of points selected in the me...

Страница 158: ...he web The web analogy derives from the nodes and connecting lines used to construct the web Nodes are math functions selected from the Add Math Processor menu parameters selected from the Add Measure Processor menu or parameter math functions from the Add Parameter Math Processor menu Another key feature of the Processing Web is that you can preview your waveform at any math or parameter node in ...

Страница 159: ... Web Editor tab to return to the web setup dialog The math and parameter locations you selected appear as outputs at the far right You may have to scroll up or down to see it 4 Touch the Add Math button and select a math function from the Add Math Processor menu The math function icon will appear on the web setup field Touch and drag the icon to the desired location 5 If you are using channel inpu...

Страница 160: ...then Scope Display in the drop down menu The scope display will return to the normal waveform display grid Viewing the Output 1 Touch Math in the menu bar then Math Setup in the drop down menu 2 Touch the Oncheckbox for the function you want to view Measuring with Cursors Cursors are important tools that aid you in measuring signal values Cursors are markers lines cross hairs or arrows that you ca...

Страница 161: ... button on the front panel repeatedly to scroll through each cursor type Turn the CURSORS knobs to adjust the position of the cursor Note The bottom cursor knob adjusts relative cursors It does not work with absolute cursor types 2 The cursors displayed will assume the positions previously set up If you want to change their position or measurement mode in the menu bar touch Cursors then Cursors Se...

Страница 162: ...r example On the Cursors Setup dialog an X Axis menu will become available from which to choose the units For example if you are placing cursors on a histogram select V histo Overview of Parameters Parameters are measurement tools that determine a wide range of waveform properties Use them to automatically calculate many attributes of your waveform like rise time rms voltage and peak to peak volta...

Страница 163: ...he Source1 field Math On Parameters Performs math addition subtraction multiplication division on parameters denoted in the Source1 and Source2 fields This feature is available with some optional math packages Advanced Web Edit Uses LeCroy s Processing Web to set up the measurement This feature which is available with the XWEB option allows you to chain practically unlimited math functions togethe...

Страница 164: ...WavePro 7Zi 163 WP700Zi OM E RevA OR If you selected Math On Parameters touch inside the Math Operator data entry field and select a math function from the pop up ...

Страница 165: ...he setup Touch the parameter list box and read the explanation in the message line at the bottom of the screen A green check mark means that the scope is returning a valid value A crossed out pulse means that the scope is unable to determine top and base however the measurement could still be valid A downward pointing arrow indicates an underflow condition An upward pointing arrow indicates an ove...

Страница 166: ...ile Minimize 2 Touch the X Stream Browser desktop icon to open the browser 3 Touch the left scope icon Connect to a local X Stream DSO device in the X Stream Browser toolbar 4 Select Measure Parameter in error P1 Out Result 5 Read the status information in line StatusDescription ...

Страница 167: ...r that computes on an entire waveform like edge level mean minimum maximum etc the value displayed represents the number of sweeps For any parameter that computes on every event the value displayed is equal to the number of events per acquired waveform If x waveforms were acquired the value represents x times the number of cycles per waveform Also the value is equal to the measurement of the last ...

Страница 168: ...ry field and choose a source for which the measurements should apply Parameter Math The instrument gives you the ability to perform arithmetic operations addition subtraction multiplication division on the results of two parameter measurements Alternatively you can apply math to a single parameter for example invert By customizing parameters in this way you can effectively extend the range of para...

Страница 169: ... delta clock to data near DC2D x delta clock to data next DC2DPOS x delta clock to data previous DC2DNEG x delta delay DDLY x delta time at level DTLEV x phase PHASE x resolution RES x mTnTmT shift BEES x mTnTmT shift sigma BEESS x mTnTmT shift sigma list BEESS Parameter Script Parameter Math In addition to the arithmetic operations the Parameter Math feature allows you to use VBScript or JavaScri...

Страница 170: ...nd outputs a parameter measurement as shown in the figure below P Script on the other hand is another VBScript or JavaScript that takes as input one or two parameters and performs a math operation on them to produce another parameter output The inputs to Param Script can also be math F1 Fx or memory M1 Mx traces The inputs to P Script can be the results of any parameter measurement not necessarily...

Страница 171: ...ters button The Source field expands to two fields 5 Touch inside the Source1 and Source2 fields and select the parameters you want to apply math to P1 to Px If you are applying math to a single parameter for example invert just touch inside the Source1 field and select a parameter P1 to Px 6 Touch inside the Math Operator field and select P Script from the Select Measurement menu 7 In the Script ...

Страница 172: ...five rising edges Therefore parameter calculations for rise time are performed only on the five pulses bounded by the gate posts The position of the gate posts is shown in the Start and Stop fields in the accompanying dialog Setting Up Measure Gate 1 Touch Measure Measure Setup on the menu bar 2 Touch the Px tab for the parameter you want to gate A Gate dialog to the right of the main setup dialog...

Страница 173: ...sors and a visual representation of what is being measured For the at level parameters Help Markers make it easier to see where your waveform intersects the chosen level This feature also displays the hysteresis band that you have set about that level You also have the option by means of an Always On checkbox to leave the Help Markers displayed after you have closed the Help Markers setup dialog Y...

Страница 174: ...l indicator and hysteresis band for at level parameters Note The choice of Simple or Detailed is applied to all parameters at the same time That is if you choose Simple markers for one parameter all parameters will be displayed in this mode 5 Touch the Always On checkbox if you want to continuously display Help Markers for this parameter Turning Off Help Markers 1 Touch the Clear All button to tur...

Страница 175: ... trace source defaults to the channel or trace whose dialog is open If a parameter it goes into the next available parameter or the last one if all are used 4 Select another parameter or touch Close From a Math Setup Dialog 1 Touch Math Fx Setup on the menu bar 2 In the Fx dialog touch the Measure button 3 Select a parameter from the pop up menu The Actions for trace source defaults to the channel...

Страница 176: ...p base On signals not having two major levels such as triangle or saw tooth waves returns same value as pkpk Standard parameter Ampl Asym aasym Amplitude asymmetry between taa and taa 1 taa taa taa taa Hysteresis argument used to discriminate levels from noise in data Available with DDM2 option Standard in DDA 5005A Apparent Pwr Product of the RMS values of the voltage and current Available with P...

Страница 177: ... base and top values over an integral number of cycles contrary to median eliminating bias caused by fractional intervals Data value for which 50 of values are above and 50 below Choose this parameter by selecting Median from the parameter table then touching the Cyclic checkbox Standard parameter cyclic RMS rms Cyclic root mean square Computes square root of sum of squares of data values divided ...

Страница 178: ...ach cycle in a waveform Reference levels and edge transition polarity can be selected Hysteresis argument used to discriminate levels from noise in data Available with JTA2 SDA and XMAP options Standard in SDA100G scopes Droop FG drpfg 1000Base T test mode 1 droop from F to G Available with ENET option Droop HJ drphg 1000Base T test mode 1 droop from H to J Available with ENET option Dtime level d...

Страница 179: ...ge transition polarity can be selected Hysteresis argument used to discriminate levels from noise in data Available with JTA2 SDA and XMAP options Standard in SDA100G scopes Edge level edge lv Number of edges in waveform Reference levels and edge transition polarity can be selected Hysteresis argument used to discriminate levels from noise in data Available with JTA2 USB2 SDA and XMAP options Stan...

Страница 180: ...l with positive edge of an eye relative to trigger or eye reference Standard in SDA and WaveExpert scopes Eye Cyc Area ecyca The area under the mean persistence trace under first UI Standard in SDA and WaveExpert scopes Eye Delay edly Time of first crossing of an eye relative to trigger or eye reference Standard in SDA and WaveExpert scopes Eye Delt Dly eddly Delay of crossing times between two ey...

Страница 181: ... Available with SDA and SDM options Standard in SDA SDA100G and WaveExpert scopes Fall 80 20 fall8020 Fall 80 20 Duration of pulse waveform s falling transition from 80 to 20 of the amplitude averaged for all falling transitions between the cursors Average duration of falling 80 20 transition On signals not having two major levels triangle or saw tooth waves for example top and base can default to...

Страница 182: ...ther pair of 50 crossings Starting with first transition after left cursor the period is measured for each transition pair Values then averaged and reciprocal used to give frequency 1 period Standard parameter Freq level freq lv Frequency at a specific level and slope for every cycle in waveform Reference levels and edge transition polarity can be selected Hysteresis argument used to discriminate ...

Страница 183: ...2 XMATH XWAV CAN02 SDA and XMAP options Standard in DDA 5005A SDA100G WaveExpert and sampling scopes Hist Max Pop hmaxp Peak with maximum population in a histogram Available with DDM2 JTA2 XMATH XWAV CAN02 SDA and XMAP options Standard in DDA 5005A SDA100G WaveExpert and sampling scopes Hist Mean hmean Average or mean value of data in the histogram Available with DDM2 JTA2 XMATH XWAV CAN02 SDA and...

Страница 184: ...eExpert and sampling scopes Hist Top htop Value of the right most of the two most populated histogram peaks Available with DDM2 JTA2 XMATH XWAV CAN02 SDA and XMAP options Standard in DDA 5005A SDA100G WaveExpert and sampling scopes Hist X peak x pk The value of the nth highest histogram peak Applies only to histograms Available with JTA2 XMATH XWAV CAN02 DDM2 SDA and XMAP options Standard in DDA 5...

Страница 185: ...option Standard in DDA 5005A Local Bsep lbsep Local baseline separation between rising and falling slopes Hysteresis argument used to discriminate levels from noise in data Available with DDM2 option Standard in DDA 5005A Local Max lmax Maximum value of a local feature If 25 of the way down toward min is more than 10 000 points the extremal value is used as the local max Hysteresis argument used t...

Страница 186: ...teresis argument used to discriminate levels from noise in data Available with DDM2 option Standard in DDA 5005A Local t min ltmn Time of the minimum value of a local feature Hysteresis argument used to discriminate levels from noise in data Available with DDM2 option Standard in DDA 5005A Local tot ltut Time a local feature spends over a user specified percentage of its peak to trough amplitude H...

Страница 187: ...of rightmost non zero bin of histogram not to be confused with maxp Standard parameter Mean Average of data for time domain waveform Computed as centroid of distribution for a histogram of the data values Average of data Gives similar result when applied to time domain waveform or histogram of data of same waveform But with histograms result may include contributions from more than one acquisition...

Страница 188: ...ls not having two major levels triangle or saw tooth waves for example may not give predictable results Standard parameter Overshoot Overshoot positive Amount of overshoot following a rising edge specified as percentage of amplitude max top ampl x 100 Waveform must contain at least one rising edge On signals not having two major levels triangle or saw tooth waves for example may not give predictab...

Страница 189: ...on a persistence trace Standard in SDA and WaveExpert scopes Per Duty Cyc pduty Duty cycle measured on a persistence trace Standard in SDA and WaveExpert scopes Period Period of a cyclic signal measured as time between every other pair of 50 crossings Starting with first transition after left cursor period is measured for each transition pair with values averaged to give final result Where Mr is t...

Страница 190: ... the More tab for signal setups Phase difference between signal and reference Standard parameter Pj Periodic component of jitter Available with SDA option Power Factor Ratio of real to apparent power Available with PMA2 option PW50 Average pulse width at the 50 point between the local baseline and the local peak or trough Hysteresis argument used to discriminate levels from noise in data Available...

Страница 191: ...r example top and base can default to maximum and minimum giving however less predictable results Standard parameter Rise level rise lv Rise at level Duration of pulse waveform s rising edges between user defined transition levels Threshold arguments specify two vertical values on each edge used to compute rise time Formulas for upper and lower values lower lower thresh x amp 100 base upper upper ...

Страница 192: ...ition one way 1 2 division total swing across the threshold for the measurement to be valid Available with JTA2 SDA and XMAP options Standard in SDA100G and WaveSurfer scopes Slew Rate slew Slew rate or local dV dt in a transition zone Available in SDA and JTA2 options Standard in SDA100G scopes SSC Diff Calculates difference between average SSC frequencies Available with PCIE option SSC Frequency...

Страница 193: ... unit interval UI A unit interval equals one clock period The Virtual Clock setup gives you a choice of Standard 1 544 MHz or Custom reference clocks You can also use a mathematically derived Golden PLL to filter low frequency jitter The cutoff frequency is user selectable Cutoff Freq 1 1 667e3 x Clock Freq Reference levels and edge transition polarity can be selected Hysteresis argument used to d...

Страница 194: ... fraction of UI Available with PCIE option TxRise Transition time from 20 to 80 for all rising edges as a fraction of UI Available with PCIE option Vcross Voltage at which two signals cross Voltage of either signal at the time when difference is zero Available with SDA and PCIE options Vdiff Used for V TX DIFFp p and V RX DIFFp p for PCI Express Available with PCIE option VTxDeRatio Ratio between ...

Страница 195: ... waveforms only Standard parameter Zero Level zero Zero level of an eye diagram Available with SDA and SDM options Standard in SDA SDA100G and WaveExpert scopes Qualified Parameters Some LeCroy instruments and software packages give you the ability to constrain parameter measurements to a vertically or horizontally limited range or to occurrences gated by a second waveform Furthermore both constra...

Страница 196: ...ng waveform is in the selected state 8 Touch inside the Level Type field and select Absolute or Percent from the pop up menu 9 Touch inside the Level field and enter the crossing level value at which you want measurements to begin using the scroll bar at the bottom of the window Touch the keypad button to enter a value using the pop up keypad OR Touch the Find Level button to automatically select ...

Страница 197: ...0 threshold levels are automatically determined by the instrument using the amplitude ampl parameter Threshold levels for rise or fall time can also be selected using absolute or relative settings r level f level if these parameters are included in your scope If absolute settings are chosen the rise or fall time is measured as the time interval separating the two crossing points on a rising or fal...

Страница 198: ...ents such as rms or mean will be biased However only the last value is actually displayed the mean being available when statistics are enabled To avoid these bias effects cyclic parameters can be chosen including crms and cmean that restrict the calculation to an integer number of cycles Determining Differential Time Measurements The instrument enables accurate differential time measurements betwe...

Страница 199: ...level and type percent or absolute Print Plot or Copy The instrument gives you the ability to output files to a printer or plotter to print to file or to e mail your files Any Microsoft Windows supported printer is supported by your instrument Printing Setting Up the Printer 1 Touch File Print Setup on the menu bar The Utilities Hardcopy dialog opens OR Press the PRINT front panel button Then touc...

Страница 200: ...ttings on the Utilities Hardcopy dialog to print the screen image Adding Printers and Drivers Note If you want to add a printer driver the driver must first be loaded on the scope 1 Touch File Print Setup on the menu bar OR Press the PRINT front panel button Then touch the Print Setup button on the Print flyout menu 2 On the Utilities Hardcopy dialog touch the Printer icon 3 Touch the Add Printer ...

Страница 201: ...the waveform leading up to the point at which the trigger condition was met and the trigger occurred The instrument offers up to the maximum record length of points of pre trigger information Post trigger delay on the other hand allows you to sample the waveform starting at the equivalent of 10 000 divisions after the event occurred Because each instrument input channel has a dedicated ADC Analog ...

Страница 202: ...eturn to Real Time mode at any time Roll mode displays in real time incoming points in single shot acquisitions that have a sufficiently low data rate The oscilloscope rolls the incoming data continuously across the screen until a trigger event is detected and the acquisition is complete The parameters or math functions connected to each channel are updated every time the roll mode buffer is updat...

Страница 203: ...nternally These internally saved settings are easy to recall later You can also save and recall your scope panel settings as a file lss on the hard disk a network location USB drive or another location Saving Scope Settings 1 Touch File Save Setup on the menu bar 2 To save the scope settings internally under Save to Internal Setup touch inside a SetupX data entry field and use the pop up keyboard ...

Страница 204: ...tup on the menu bar Touch the Recall Default button under Recall Default Setup Saving and Recalling Waveforms Saving Waveforms 1 Touch File Save Waveform on the menu bar 2 In the Save Waveform dialog touch the Save To Memory button or File button 3 Touch inside the Source field and select a source from the Select Source pop up window The source can be any trace for example a channel C1 C4 math fun...

Страница 205: ... output is used for persistence traces 6 Touch the Browse button next to the Save file in directory field and browse to the location where you want the file saved The file name is assigned automatically and is shown below the field 7 Touch the Save Now button Auto Save You can use the Auto Save feature to automatically save a waveform to disk after each new trigger You can enable Auto Save from Sa...

Страница 206: ...ide the Next file will be recalled from data entry field and enter the path using the pop up keyboard Or touch the Browse button to navigate to the file 3 Touch the Recall Now button Disk Utilities Use the Disk Utilities dialog to delete files or create folders Note All of the Disk Utilities can also be accomplished using the standard file management tools in Microsoft Windows Deleting a Single Fi...

Страница 207: ...erial triggers are integrated into the oscilloscope no external hardware is used and are selected through the normal oscilloscope trigger menus I2 C and SPI signals are input to the oscilloscope through normal passive or active probes such as LeCroy s ZS Series of high impedance active probes Decoding is accessed from the Analysis pull down menu in the menu bar The decoding is overlaid on top of t...

Страница 208: ...scope an additional set of Serial Decode and Decode Setup dialog boxes will be provided for setup of protocol format as necessary and decoding These can be accessed from the Analysis menu Decode Protocol Selections As serial decode options are added to your oscilloscope additional protocol selections are available in a pop up menu within the Decode Setup dialog box D Series Software The D option a...

Страница 209: ...uired by the oscilloscope It can also be set to an absolute voltage level if desired For serial data signals with embedded clocks i e CAN the algorithm then performs an analysis of the serial data message to determine the nominal bit width The clock rate bit width is measured directly from the clock line for other serial data formats i e I2 C and SPI Once the clock signal is acquired and the decod...

Страница 210: ... Trigger Type menu in the Trigger dialog and a new set of dialogs for Decode setup These dialogs are shared by all the low speed serial protocols that LeCroy offers so all serial trigger and serial decoding selections will be grouped into a common selection with nearly identical selection and setup These dialogs are conveniently accessed with just one or two touches of the screen Trigger Methods t...

Страница 211: ...box shows a summary of which decoders are ON and how they are set up In addition there are shortcuts to Decode Setup and Search A sample dialog box is shown below This dialog box reflects an oscilloscope that has both the I2 C and SPI options There are four independent decoders A user can operate up to four at a single time though the limitation may be on the number of channels that can be accommo...

Страница 212: ... Search and Table Configure Table and Export Table Search Push this button to open a Zoom Zx trace that has as its source the corresponding Channel Cx trace In addition the right hand dialog in the Zoom trace has Search options specific to the serial protocol that the Source is assigned to Decode Setup Dialog The Decode Setup dialog box is where the details of a specific protocol decode are entere...

Страница 213: ...n line Help for information about how to Store and Recall Waveforms A Math Function would be used to view decoded data on Sequence mode acquisitions Sequence Mode is a unique capability whereby you can utilize oscilloscope memory to capture events widely spaced in time and view them sequentially Reference the chapter on Isolating and Analyzing Serial Bus Activity for more information on setting th...

Страница 214: ... at decode results and quickly zoom to a specific message When displayed the protocol results table will appear under the waveform grid It looks like the following example this example is for I2 C each protocol table will look slightly different The slider bar on the right can be used to navigate through the protocol table If the slider bar is yellow then you can use the ADJUST knob on the oscillo...

Страница 215: ...e setting This can be set to any value from 0 01 to 10 If the bit rate is outside the tolerance range set then the calculated bit rate will appear as red text in the table Searching for Messages There are several ways to search for specific messages Touch the decoded waveform to open a pop up dialog Touch the Search button in the Serial Decode summary dialog box or in the Decode Setup dialog box ...

Страница 216: ...ks in the EEPROM It can also aid in monitoring DATA outputs from I2 C based sensors such as analog to digital converters and triggering when DATA is outside a safe operating range In both cases verifying proper operation becomes a simple task Other powerful and user friendly features included in I2Cbus TD trigger include x Ability to define an ADDR or DATA condition in either binary or hexadecimal...

Страница 217: ... trigger Type Select the appropriate serial trigger Then the menu will automatically change to a different tab in the Trigger dialogs The tab will be named after the serial trigger that you have selected Creating an I2 C Trigger Condition The I2 C Trigger dialog with detail on some of the setup conditions is shown in the images that follow Selection of Trigger Type results in dynamic changes to th...

Страница 218: ... then use the oscilloscope front panel ADJUST knob to adjust Or touch inside the number area twice and select a value using the pop up numeric keypad The set Level appears as a dotted horizontal line across the oscilloscope grid If your initial decoding indicates that there are a number of error frames make sure that the level is set to a reasonable value Include R W Bit Some engineers think of th...

Страница 219: ...DATA and CLOCK signals Trigger Type Selection The I2 C trigger can be configured to trigger on simple conditions i e the presence of a START STOP RESTART bit or the absence of an ACK bit NO ACK In addition more complex trigger conditions can be created using ADDR ADDR DATA FRAME LENGTH or EEPROM setups If one of the more complex trigger conditions is selected then reference the appropriate section...

Страница 220: ...then this selection will be grayed out and not selectable Data Setup These setup selections are displayed if the Trigger Selection is ADDR DATA or EEPROM Data Pattern Value The pattern value is entered in either Binary or Hexadecimal mode depending on the previous selection of Setup Mode There are two selections for pattern value Pattern Value and Pattern Value To The second selection is exposed f...

Страница 221: ...this to specify a particular location of data such as a sub address memory block that the Pattern Value must occupy in order for triggering to occur For ADDR DATA use this to specify a location where the data values should be placed without using don t care X values in the pattern value X values would be nonsensical in an INRANGE or OUTRANGE conditional setup Values can be set from 0 2047 bytes Se...

Страница 222: ...EPROM failed to acknowledge a byte written Overview of SPIbus Both SPIbus TD and D options contain powerful software algorithms to extract serial data information from physical layer waveforms measured on your oscilloscope The extracted information is overlaid annotated on the actual physical layer waveforms and color coded to provide fast intuitive understanding The SPIbus TD option contains a da...

Страница 223: ...rial trigger Then the menu will automatically change to a different tab in the Trigger dialogs The tab will be named after the serial trigger that you have selected Creating a SPI Trigger Condition The SPI Trigger dialog with detail on some of the setup conditions is shown in the images that follow The SPI trigger dialog is very flat there are few dynamic changes to the dialog based on selections ...

Страница 224: ...de the number area twice and select a value using the pop up numeric keypad The set Level appears as a dotted horizontal line across the oscilloscope grid If your initial decoding indicates that there are a number of error frames make sure that the level is set to a reasonable value Include R W Bit Some engineers think of the 7 bit address pattern as including the R W bit i e 8 bits and others thi...

Страница 225: ...CK signals SPI Trigger Type Selection The SPI trigger can be configured to trigger on simple conditions i e the presence of a START STOP RESTART bit or the absence of an ACK bit NO ACK In addition more complex trigger conditions can be created using ADDR ADDR DATA FRAME LENGTH or EEPROM setups If one of the more complex trigger conditions is selected reference the sections below for information on...

Страница 226: ...SB format Therefore conversion of address values from binary to hex when don t care values are used will be on that basis Direction Enter a Direction either Read Write or Don t Care for the Address value If you have elected to use 7 bit addresses with the R W bit included in the address value then this selection will be grayed out and not selectable SPI Data Setup These setup selections are displa...

Страница 227: ...tputs from I2 C based sensors such as analog to digital converters and triggering when DATA is outside a safe operating range In both cases verifying proper operation becomes a simple task Pattern Length The pattern length value defaults to the length in bytes of the pattern set in the Pattern Value selection If you were to change the length to be less than this value it would truncate the beginni...

Страница 228: ...value with a defined length of data bytes Bytes Length Specify a data length value between 0 and 2047 The default value is 1 If the Data Length Condition see below is selected to be either INRANGE or OUT of RANGE then this selection will be for the minimum data length value i e the lower value of the range you wish to include or exclude Note All values entered in this field are always in decimal f...

Страница 229: ... are discussed next Capturing Long Pre Trigger Time LeCroy oscilloscopes are available with optional very long acquisition memory For instance the WaveRunner Xi Series oscilloscopes can capture up to 12 5 Mpts on 4 channels or 25 Mpts on 2 channels If your Serial Data signals are 1 Mb s and you sample at the minimum required and available sample rate 5 MS s you would be able to capture 5 seconds o...

Страница 230: ... re armed for a new trigger To minimize dead time use Sequence Mode Storing Triggers LeCroy oscilloscope s have a powerful capability called Sequence Mode that allows you to store all triggered events by minimizing the dead time between triggers to 800 nanoseconds This is ideal for finding repetitive causes of problems on your serial data buses or associated signals Sequence Mode uses long acquisi...

Страница 231: ...et up the Serial Trigger to capture the event you desire For instance you might want to trigger on a specific address or data value and capture long pre trigger time to determine what precedes that message In this example we ve used a simple I2 C Start trigger To begin the sequence mode acquisition press the front panel SINGLE trigger button Each time the trigger condition is met the TRIG D light ...

Страница 232: ...l data was acquired on in this case Channel 2 To display the trace check the Trace On checkbox To select the segment to view touch the Select tab and select a segment using the pop up keypad or the front panel adjust knob 7 To view decoded data on the individual segment set up the Decode to use the Math trace as the source for Data in this case F4 is the source If you wish to change the segment th...

Страница 233: ...Operator s Manual WP700Zi OM E RevA 232 8 To maximize display space you could turn off the Channel and just select the segment that you wish to view ...

Страница 234: ... as shown to the right Then you will see a display of time stamp information for each segment in the sequence acquisition as shown below 10 Ten time stamps will fit on the display at one time You can choose which ten to display by using the Select Segment control You can also page through the segments one at a time by using the ADJUST knob on the front panel I2 C and SPI Specifications ...

Страница 235: ...ion data entry field and enter a value using the slider bar at the bottom of the window Click the keypad button on the slider bar to enter a value using the pop up numeric keypad or use the up down arrows to adjust the value 3 Touch inside the Delay data entry field and type in a value or use the slider bar at the bottom of the window Click the keypad button on the slider bar to enter a value usin...

Страница 236: ...de the Maximum Sample Point field to enter a value using the scroll bar at the bottom of the window OR Touch the Fixed Sample Rate button and touch inside the Sampling Rate field to enter a value using the scroll bar at the bottom of the window 3 Touch inside the Time Division data entry field and set a time per division Note If you are currently acquiring waveforms you will notice a change in sam...

Страница 237: ...on trace label if you want to change any settings in the Trend dialog Note Turning off a trace for which trend data is being collected will reset the trend If it is necessary to continue data collection for the trend create a zoom trace of the channel trace before turning off the channel trace Creating a Track View 1 In the menu bar touch Measure Measure Setup 2 Touch one of parameter tabs P1 thro...

Страница 238: ...want to define a fixed pulse width time or time range only Glitch trigger makes no provision for voltage levels or ranges Interval While Glitch trigger performs over the width of a pulse Interval trigger performs over the width of an interval the signal duration the period separating two consecutive edges of the same polarity positive to positive or negative to negative Use interval trigger to cap...

Страница 239: ...Logic trigger enables triggering on a logical combination pattern of five inputs CH1 CH2 CH3 CH4 EXT You have a choice of four Boolean operators AND NAND OR NOR and you can stipulate the high or low voltage logic level for each input independently TV Not available on all instruments TV triggers provide stable triggering on standard or custom composite video signals Use them on PAL SECAM or NTSC sy...

Страница 240: ...menu bar 2 Touch inside the View AUX IN on Channel 3 checkbox The Coupling field is disabled 3 Press the Channel 3 front panel button to turn on Channel 3 and display the setup dialog 4 Perform vertical setups for your auxiliary input in the Channel 3 dialog 5 Touch Vertical Channels Status from the menu bar to view a summary of the Aux Input setup Software Assisted Trigger For SDA 9000 11000 1800...

Страница 241: ...rigger level set in the main Trigger dialog to exclude noise 3 The Auto and Normal buttons determine the behavior when trigger crossings are not found in the trigger source waveform x Auto mode allows all waveforms through the channel x Normal mode allows waveforms only with a trigger crossing within the horizontal gate region through the channel 4 Set Start and Stop time values on the Horizontal ...

Страница 242: ...ticated triggers that enable you to use basic or complex conditions for triggering Use SMART Triggers for signals with rare features like glitches Trigger Settings Horizontal and Vertical adjustments are typically made for all trigger types using either the Delay or Level knobs on the front panel of the instrument or their respective fields on the Timebase setup dialog x Horizontal Turn the DELAY ...

Страница 243: ...t from the pop up menu 4 Select a coupling mode 5 Touch inside the Level data entry field Using the pop up numeric keypad enter a value in millivolts or use the up down buttons to increase or decrease the value in increments of 1 mV Or touch one of the preset value buttons 6 Select the holdoff by touching the Time or Events buttons Use the slider bar at the bottom of the window to enter values via...

Страница 244: ...al trigger source you will also need to set a coupling mode Touch inside the Level data entry field and enter a value using the slider bar at the bottom of the window Click the keypad button on the slider bar to enter a value using the pop up keypad Touch the Default button to set the level to zero mV 1 Select Positive or Negative polarity 2 Touch the Less Than button and enter a pulse width value...

Страница 245: ... qualified trigger can occur immediately after the validation or following a predetermined time delay or number of potential trigger events The time delay or trigger count is restarted with every validation Within Time creates a time window within which a trigger can occur Wait Time determines a delay from the start of the desired pattern After the delay timeout and while the pattern is present a ...

Страница 246: ...h and Interval trigger types from the Then trigger on Event B section Otherwise Edge is the only choice available State Triggers Before we proceed to step 5 of Qualified Trigger let s explain a few things about State Triggers A State trigger is another Qualified trigger however instead of using the edges of the qualifying inputs State trigger uses the logic state of the inputs to qualify the trigg...

Страница 247: ...r How Pattern Trigger Works Pattern Trigger enables triggering on a logical combination of up to five inputs CH 1 CH 2 CH 3 CH 4 and EXT The combination of inputs is referred to as a pattern There are four logic gates available AND NAND OR NOR A trigger state is either high or low high when a trigger source is greater than the trigger level threshold and low when less than it For example an AND pa...

Страница 248: ...ouch one of the Holdoff By buttons on the Holdoff tab Then touch inside a holdoff data entry field and enter a value using the slider bar at the bottom of the window Click the keypad button on the slider bar to enter a value using the pop up keypad Touch the Default button to use preset values 4 If applicable touch inside the State fields for channels 1 4 or EXT and select a logic state of either ...

Страница 249: ... custom composite video signals Use them on PAL SECAM or NTSC systems TV Trigger Setup 1 Touch the Trigger descriptor label 2 In the Trigger dialog touch the TV trigger button 3 Touch one of the TV Standard buttons to select a television standard 4 Touch inside the Source field and select the Ext location of Trigger Out cable from the pop up menu Note The channel that you have the VT75 Module conn...

Страница 250: ...AM and the interlace factor selected For NTSC line 526 is the same as line 1 for PAL line 626 is the same as line 1 9 Touch inside Field and make a selection from the pop up menu The maximum field number that you can select is limited by your selection in of Fields If of Fields above is set to 1 this selection is disabled Custom TV Standard Trigger Setup 1 In the TV Standard field touch the Custom...

Страница 251: ...e dialog to configure the trigger for ANY line using the checkbox or a specific Line Field and Level value Set the Line and Level values using the slider bar s value slider pop up keypad button or Default button 6 The Ext tab can be used to make other TV trigger input attenuations choose either X1 or 10 and impedance choose 50 1M or Gnd selections Note Use the TriggerScan tab to run the Trainer a ...

Страница 252: ...e signal The signal s width as determined by the instrument trigger comparator depends on the DC trigger level If that level were to be set at the middle of a sine wave for example the width could then be considered as the half period But if the level were higher the signal s width would be considered to be less than the half period Figure 4 19 Glitch Trigger In this example triggering on a pulse ...

Страница 253: ...riggers Work While Glitch trigger performs over the width of a pulse Interval trigger performs over the width of an interval with the signal duration period separating two consecutive edges of the same polarity positive to positive or negative to negative Use Interval trigger to capture intervals that fall short of or exceed a given time limit In addition you can define a width range to capture an...

Страница 254: ...inting arrow indicates a potential trigger while the bold one shows where the actual trigger occurs on the positive edge after the selected interval Interval In Range This Interval Trigger is generated whenever an interval between two edges of the same slope falls within a selected range The instrument initializes and restarts the timing for the interval whenever the selected edge occurs Figure 4 ...

Страница 255: ...e using the slider bar at the bottom of the window Click the keypad button on the slider bar to enter a value using the pop up keypad Touch the Default button to use a preset value 6 Select Positive or Negativepolarity 7 Touch the Less Than button and enter a pulse width value in the Upper Limit data entry field OR Touch the Greater Than button and enter a value in the Lower Limit data entry field...

Страница 256: ... TriggerScan tab to run the Trainer a wizard like tool to configure triggers Save and Load trigger setups for reuse Dropout Trigger Used primarily in single shot applications and usually with a pre trigger delay Dropout trigger can detect lost signals The trigger is generated at the end of the timeout period following the last trigger source transition How Dropout Trigger Works Figure 4 23 Dropout...

Страница 257: ...vel button is available to automatically set the Level Note Use the TriggerScan tab to run the Trainer a wizard like tool to configure triggers Save and Load trigger setups for reuse Runt Trigger Not available on all instruments the Runt trigger is programmed to occur when a pulse crosses a first threshold line and fails to cross a second threshold line before re crossing the first You can select ...

Страница 258: ...tton to set up a precise pulse width range by setting Lower Limit and Upper Limit values using the slider bar pop up keypad button or the Default button Touch the In Range button on some oscilloscopes Then touch the Delta button to set up a nominal range plus or minus a delta value in seconds using the slider bar pop up keypad button or the Default button OR Touch the Out Of Range button on some o...

Страница 259: ...pad Touch the Default button to use preset values 5 Select Positive or Negativepolarity 6 Touch the Less Than button on some oscilloscopes and enter a pulse width value in the Upper Limit field using the slider bar pop up keypad button or the Default button OR Touch the Greater Than button on some oscilloscopes and enter a pulse width value in the Lower Limit field using the slider bar pop up keyp...

Страница 260: ...he trigger circuit generates an event a change in the input signal that satisfies the trigger conditions The selected trigger level is associated with the chosen trigger source Note that the trigger level is specified in volts and normally remains unchanged when the vertical gain or offset is modified The Amplitude and Range of the trigger level are limited as follows x 5 screen divisions with a c...

Страница 261: ...ing and level are not relevant for this selection x The signal applied to the EXT BNC connector EXT This can be used to trigger the oscilloscope within a range of 400 mV on EXT 4 V with EXT 10 as the trigger source or 40 mV with EXT 10 as the trigger source x A logic pattern Holdoff by Time or Events Holdoff is an additional condition of Edge trigger It can be expressed either as a period of time ...

Страница 262: ...been exceeded Hold Off by Events Select a positive or negative slope and a number of events An event is the number of times the trigger condition is met after the last trigger A trigger is generated when the condition is met after this number counted from the last trigger The count is restarted on each trigger For example if the event number is two the trigger will occur on the third event Figure ...

Страница 263: ...on the screen All acquisition settings are preserved and you can use all the functions of the oscilloscope to find the root cause of these anomalies including WaveScan Histograms and advanced analysis Training TriggerScan The TriggerScan Trainer inspects a currently acquired waveform and automatically builds a list of common trigger setups used to find rare events PLEASE NOTE THE FOLLOWING x You m...

Страница 264: ...touch the Trigger tab and set the new trigger Then touch the Add New button to add the new trigger to the Trigger List 4 If you want to delete a trigger setup highlight the setup in the Trigger List and touch the Delete Selected button Note If you want to delete all trigger setups in the Trigger List touch the Delete All button 5 If you want to replace the selected trigger setup with the current t...

Страница 265: ...ties dialog OR Touch the Status tab Remote communication From the Remote tab on the Utilities dialog you can set up remote communication You can select a network communication protocol establish network connections and configure the Remote Control Assistant log from the Remote dialog The choice of communication protocols is limited to TCPIP and GPIB PLEASE NOTE THE FOLLOWING x GPIB is an option an...

Страница 266: ...on printing and printer setup refer to the Printing topic Clipboard The Clipboard selection on the Hardcopy tab saves the screen image on the clipboard so you can paste a file into another application like MS Word for example Saving a Screen Image to the Clipboard 1 Touch Utilities Utilities Setup on the menu bar 2 Touch the Hardcopy tab then the Clipboard icon 3 Touch the Colors field and choose ...

Страница 267: ...tilities dialog you first have to set up the e mail server and recipient address in Preference Setup E Mailing a Screen Image 1 Touch Utilities Utilities Setup on the menu bar 2 Touch the Hardcopy tab then the E mail icon 3 Touch inside the File Format data entry field and select a graphic file format from the pop up menu 4 Touch the Colors field and choose Standard to print the screen as it appea...

Страница 268: ...e slider bar at the bottom of the window Click the keypad button on the slider bar to enter a value using the pop up numeric keypad 5 Touch inside the Frequency data entry field and enter a value using the slider bar at the bottom of the window Click the keypad button on the slider bar to enter a value using the pop up numeric keypad Date and Time From the Date and Time tab on the Utilities dialog...

Страница 269: ...oy Sales and Service office or visit our Web site at http www lecroy com options Options that you purchase add performance to your instrument This added performance is seen in the new math functions or parameters that you can choose from when doing Measure or Math setups Preferences Enabling Audible Feedback You can choose to have audible confirmation each time you touch a screen or front panel co...

Страница 270: ...shown in the channel setup dialog always indicates volts However when Div is selected for the Offset Control the offset in volts is scaled proportional to the change in gain thereby keeping the division on the grid constant 1 Touch Utilities Preferences on the menu bar 2 Touch the Acquisition tab 3 Under Offset Setting constant in touch either the Div or Volts button Setting a Delay Control As you...

Страница 271: ...end Test Mail button The test message reads Test mail from name of scope s email address Acquisition Status For each general category of oscilloscope operation you can view a summary of your setups To access these status dialogs choose the following x Vertical Channels Status on the menu bar x Timebase Acquisition Status on the menu bar x Trigger Acquisition Status on the menu bar x Math Math Stat...

Страница 272: ...ng the Waveform s Position Turn the VERTICAL OFFSET adjust front panel knob directly above the channel button whose waveform you want to move vertically Or you can touch inside the Offset field and type in a value on the pop up keypad To set the vertical offset to zero touch the Zero Offset button directly below the Offset field Coupling The choices of coupling are as follows x DC 50 all instrumen...

Страница 273: ... bandwidth Interpolation Setup 1 Touch the button for the channel you want to set up for example 2 In the dialog area touch inside the Interpolation data entry field under Pre Processing Pre Processing is meant as before Math processing 3 Touch inside the Interpolation data entry field A pop up menu appears offering Linear or Sinx x interpolation 4 Touch the button for the type of interpolation yo...

Страница 274: ...try field and enter a value using the pop up numeric keypad Group Delay Compensation Group delay is defined as the rate of change of the total phase shift with respect to angular frequency through a device or transmission medium An unavoidable consequence of correcting for group delay is that preshoot and overshoot will be added to the signal x Pulse Response A delay compensation that minimizes pr...

Страница 275: ...ed optical recording drives that have constant angular velocity CAV or zone constant linear velocity ZCLV parameter measurements support automatic determination of the clock period Histogramming Histograms can be created for any waveform parameter They are displayed based on a set of user settings such as bin width or number of parameter events to be used Histogram parameters are provided for meas...

Страница 276: ... Shift EES or their sigmas BESS or EESS the results can be shown in a table Select nT Table from the Show menu to display a table of the average value of BES or EES for each subject nT vs each preceded or followed nT Note For EES Following nT is displayed instead of Preceding nT The nT is the range specified starting from the low T The subject T i e s n will also start from Low T to High T Setup a...

Страница 277: ...Operator s Manual WP700Zi OM E RevA 276 AORM Measurement Menus Field Description View Allows you to quickly select the most common views with graphing ...

Страница 278: ...n on or off the display of statistics values Data Source This can be a channel math function or memory trace A Use Equalizer checkbox is provided to apply a filter to the data source Data Gate This can be a channel math function memory trace or other It specifies the input that will be used to determine where to perform measurements on the input signal The polarity is always high Use Equalizer Thi...

Страница 279: ...lute crossing level Clock The clock need only be specified if the parameter requires a clock for the calculation or if it is used as the source of the period Clock Period By selecting From Data you can have the clock recovered from the data In this case all other clock setup fields except Clock Slope are unavailable When From Clock is selected the period is automatically measured from the clock pr...

Страница 280: ...he range of n indices that define the pits spaces used in the calculation The range of n coupled with T are used to categorize the pits spaces based on their widths From nT To nT Specifies the range of n indices that define the pits spaces used in the calculation The range of n coupled with T is used to categorize the pits spaces based on their widths Measurements Table Measurement Parameters setu...

Страница 281: ...ate not available for all measurements see Measurement Table next for details When XY Plot is selected a trend plot of the selected parameter is displayed in a second grid and a new tab AORM Trend Y appears Find Scale determines the best scaling for trends center and height This occurs automatically if the Auto Find Scale checkbox is checked Equalizer and PLL Dialog Field Description Track Clock C...

Страница 282: ...ycles are shown which will provide four freq parameter values for each histogram on each sweep With a freq parameter selected a histogram based on it can be specified Histogram Trace Setup Dialog To the right of the main setup dialog a Histogram setup dialog is displayed Each time a waveform parameter value is calculated it can be placed in a histogram bin Enter the Bins from 20 to 2000 You can se...

Страница 283: ...rtical scale setting as required ensuring that the highest histogram bin does not exceed the vertical screen display limit The Center and Width fields allow specification of the histogram center value and width per division The width per division multiplied by the number of horizontal display divisions 10 determines the range of parameter values centered on the number in the Center field used to c...

Страница 284: ...an also configure the center and height of the trend in the base units of the parameter being trended However this is not a requirement and Find Scale can be used to center the trend after it has been calculated Center is for selecting the mantissa exponent or number of digits resolution The configuration is the value at the horizontal center line on the grid while units are those of the parameter...

Страница 285: ... values and corresponding trend events How to Read Trends A trend is like any other waveform its horizontal axis is in units of events with earlier events in the leftmost part of the waveform and later events to the right And its vertical axis is in the same units as the trended parameter When the trend is displayed trace labels appear in their customary place on the screen identifying the trace t...

Страница 286: ...nfiguration options are available for each parameter except as noted in this table Parameter Range of nT Subject nT Dp2c x Dp2cs x BEES x BES x x BESS x x EES x x EESS x x EDGSH x PAA x Pit asym x Pit base x Pit max x Pit middle x Pit minimum x Pit moda x Pit num x Pit res x Pit top x Pit width x T pit x Timj x Available from Measure dialog ...

Страница 287: ...rop down menu Touch inside the View field and select a graph display from the pop up menu Touch inside the Show field and select a display mode A default group of parameters is automatically displayed when Parameter is selected In addition if Show Statistics is checked standard statistics mean min max sdev num are also displayed When nT Table is selected a default list of nT is displayed ...

Страница 288: ...the Select Measurement menu accessible from the Measure dialog Setting Levels To identify pits or spaces thresholds and hysteresis are set Touch inside the Data Source field and select a signal source Check Use Equalizer to apply a filter to the Data Source To set up the equalizer touch the Equalizer and PLL tab Touch inside the Data Slope field and select an edge from the pop up menu ...

Страница 289: ...om Data from the Clock Period menu if you want to extract the clock from your input waveform In this case all other clock setup fields become unavailable except Clock Slope Choose Pos Neg or Near Near means the nearest clock edge to the data edge To keep noise out of parametric measurements set up a hysteresis band in divisions about a level The level can be set to Absolute volts or Percent In eit...

Страница 290: ...e above three items in different parameter setups Pit or Space Identification This is determined uniquely by the threshold hysteresis and edge polarity of threshold crossings A positive threshold crossing indicates the start of a positive polarity pit and the end of a negative polarity space A positive threshold crossing followed by a negative threshold crossing fully delineates a pit A negative c...

Страница 291: ...ions reversed x For the entire signal only a space can be identified after a pit and only a pit can be identified after a space x All subsequent features are identified by crossing into the appropriate zone after the end of the previous feature For a pit this is Zone 3 and for a space it is Zone 1 The end of the previous feature is the beginning of the current feature being identified The subseque...

Страница 292: ...polarity subject pit and nearest positive clock edge time between beginning edge of negative polarity subject space and nearest positive clock edge time between beginning edge of subject pits and spaces to nearest positive clock edge Negative time between beginning edge of positive polarity subject pit and nearest negative clock edge time between beginning edge of negative polarity subject space a...

Страница 293: ...PLAYED Parameter Statistics Off All values of the time between beginning edge of the subject n pit space and nearest clock edges for all subject pits spaces preceded by the spaces pits within the selected nT range for the last acquisition Parameter Statistics On Average minimum maximum and sigma of the beginning edge shift calculated for all identified pit space pairs within the selected nT range ...

Страница 294: ... is used and statistics is on This is because the two measurements are not the same The BESS measurement normalizes the results for each n by subtracting the mean BES from each BES in the nth distribution This results in a superposition of mean centered distributions not a superposition of 0 centered distributions contributing to BES measurements BESS will always be less than or equal to the stand...

Страница 295: ...ve polarity subject pit and nearest positive clock edge time between ending edge of negative polarity subject space and nearest positive clock edge time between ending edge of subject pits and spaces to nearest positive clock edge Negative time between ending edge of positive polarity subject pit and nearest negative clock edge time between ending edge of negative polarity subject space and neares...

Страница 296: ...owed by the spaces pits within the selected nT range for the last acquisition Parameter Statistics On Average minimum maximum and sigma of the ending edge shift calculated for all identified pits spaces pairs within the selected nT range for all acquisitions since the last CLEAR SWEEPS operation nT Table List of values of the average ending edge shift for each nT space pit within the selected rang...

Страница 297: ...normalized ending edge shift values for pits spaces of interest for last acquisition Parameter Statistics On average minimum maximum and sigma of the ending edge shift sigma value calculated per acquisition for all acquisitions since the last CLEAR SWEEPS operation nT Table List of values of the standard deviation of the ending edge shift values for each nT spaces pit within the selected range fol...

Страница 298: ...able units If absolute time is specified the value is simply the time as indicated above If percent is specified the value of the measurement is the time normalized to the clock period For all pits a valid measurement will be obtained only when both edges of the leading and trailing pits spaces can be determined that is there is a hysteresis qualified threshold crossing beginning the start pit spa...

Страница 299: ...g edges of positive polarity pits If Neg negative is selected the measurement is performed from the leading edges of negative polarity spaces And if Both is selected the leading edges of both pits and spaces are used in the calculation The sizes of pits or spaces used in the measurement are also determined by the range of nT values chosen CLOCK EDGE DATA SLOPE Pos Neg Both positive time between le...

Страница 300: ...ns ORM parameter calculations can be displayed histogrammed and trended in a variety of ways DISPLAY TYPE VALUE DISPLAYED Parameter Statistics Off All values of the average time between leading pit space edges and nearest clock edges for all pits spaces within the selected nT range for the last acquisition Parameter Statistics On Average minimum maximum and sigma of the Delta Pit to Clock calculat...

Страница 301: ...tatistics is on This is because the two measurements are not the same DP2CS measurement normalizes the results for each n by subtracting the mean DP2C from each DP2C in the nth distribution This results in a superposition of mean centered distributions not a superposition of 0 centered distributions contributing to DP2C measurements DP2CS will always be less than or equal to the standard deviation...

Страница 302: ...longing to the nth index When edge shift is configured as a custom parameter with a range of n the overall edge shift is calculated and displayed as the weighted average of the edge shift values calculated above The measurement calculation is compliant with the definition of Edge Shift as defined by ISO IEC JTC1 23 14517 Section 22 4 Display Options ORM parameter calculations can be displayed hist...

Страница 303: ...imply the difference between the width calculated and the ideal width since there is only one pit space of that nT width thus The 3T edge shift value is the average difference In an nT Table display these three values would be shown in the appropriate nT location More On Edge Shift A good approach to understanding the operation of the edge shift parameter with different modes of operation starts b...

Страница 304: ...lting from each nT distribution for the last acquisition Note The standard deviation of superimposed Edge Shift distributions is not the same as Timing Jitter LPER Local Period Description Local Period provides a measurement of the clock period of each clock cycle up to the maximum number of cycles governed by memory limitations Histogramming and statistics can be used to provide a clock jitter me...

Страница 305: ... pit space width Display Options ORM parameter calculations can be displayed histogrammed and trended in a variety of ways DISPLAY TYPE VALUE DISPLAYED Parameter Statistics Off Single value of the average amplitude for all pits spaces of interest for last acquisition Parameter Statistics On Overall average minimum maximum and sigma of the single average amplitude value calculated per acquisition f...

Страница 306: ...nd high largest nT values to use in performing the calculation are provided by the user through the associated measurement configuration options Midpoint designates the midpoint value between the average top and base for a specified nT The value shown is in units of percent Display Options ORM parameter calculations can be displayed histogrammed and trended in a variety of ways DISPLAY TYPE VALUE ...

Страница 307: ...ue per space in the nT range contributing a value to the histogram or trend The value displayed on the custom parameter display line is the average of all such base calculations nT Table mode provides an average base measurement for each n index Display Options ORM parameter calculations can be displayed histogrammed and trended in a variety of ways The following table provides a concise descripti...

Страница 308: ... voltage value of pits of interest It provides a comparison of how the maximum point in the waveform corresponds to the ptop value When pmax is configured as a custom parameter all maximums within the single nT or range of nT are calculated Histogramming or trending such a configuration would result in one value per pit in the nT range contributing a value to the histogram or trend The value displ...

Страница 309: ...gram graph of the value of the maximum for all pits within the selected nT range for all acquisitions since the last CLEAR SWEEPS operation Trend Function Trend graph of the value of the maximum calculated for each pit that is within the selected nT range for all acquisitions since the last CLEAR SWEEPS operation Example This waveform contains a single pit whose max is computed as 26 1 mV The same...

Страница 310: ...lculated per acquisition for all acquisitions since the last CLEAR SWEEPS operation nT Table List of the middle level values for each group of pits spaces of common nT width for the last acquisition Histogram Function Histogram of the single middle level value calculated for each acquisition for all acquisitions since the last CLEAR SWEEPS operation Trend Function Trend of the single middle level ...

Страница 311: ...d trended in a variety of ways DISPLAY TYPE VALUE DISPLAYED Parameter Statistics Off All values of the minimum for all pits within the selected nT range for the last acquisition Parameter Statistics On Average minimum maximum and sigma of the minimum for all pits that are within the selected nT range for all acquisitions since the last CLEAR SWEEPS operation nT Table List of values of the average ...

Страница 312: ...DC coupled optical data waveform otherwise incorrect values will result Display Options ORM parameter calculations can be displayed histogrammed and trended in a variety of ways DISPLAY TYPE VALUE DISPLAYED Parameter Statistics Off Single value of the modulation amplitude for the last acquisition Parameter Statistics On Average minimum maximum and sigma of the single modulation amplitude value cal...

Страница 313: ...alculated automatically 1 pmoda 3T paa 11T top 2 pmoda 11T paa 11T top 3 paa 3T 4 paa 11T 5 top 11T P1 contains the ratio of P3 to P5 P2 contains the ratio of P4 to P5 PNUM PIT NUMBER Description Pit Number provides a measurement of the number of pits or spaces of interest or both When pnum is selected as a parameter measurement the total number of pits and or spaces for the selected nT range is d...

Страница 314: ... selected range of nT for the last acquisition Histogram Function Histogram graph of the single value of the number of pits spaces within the selected nT range calculated each acquisition for all acquisitions since the last CLEAR SWEEPS operation Trend Function Trend graph of the single value of the number of pits spaces within the selected nT range calculated each acquisition for all acquisitions...

Страница 315: ...cs On Overall average minimum maximum and sigma of the single pit resolution value calculated per acquisition for all acquisitions since the last CLEAR SWEEPS operation Histogram Function Histogram of the single pit resolution value calculated per acquisition for all acquisitions since the last CLEAR SWEEPS operation Trend Function Trend of the single pit resolution value calculated per acquisitio...

Страница 316: ...ment for each n index Display Options ORM parameter calculations can be displayed histogrammed and trended in a variety of ways DISPLAY TYPE VALUE DISPLAYED Parameter Statistics Off All values of the top for all pits within the selected nT range for the last acquisition Parameter Statistics On Average minimum maximum and sigma of the top for all pits within the selected nT range for all acquisitio...

Страница 317: ...ORM parameter calculations can be displayed histogrammed and trended in a variety of ways The table provides a concise description of the value or values displayed using each approach DISPLAY TYPE VALUE DISPLAYED Parameter Statistics Off All values of the pit width for all pits spaces within the selected nT range for the last acquisition Parameter Statistics On Average minimum maximum and sigma of...

Страница 318: ...it widths and to determine whether the separation is acceptable The scope is set up to acquire the optical data waveform by assigning Channel 1 to the data signal at a time div of 0 2 ms so that many pits spaces can be gathered quickly The signal is AC coupled so the threshold is set to 0 mV The pwid custom parameter is assigned to P1 and configured in the following manner hysteresis 0 5 divisions...

Страница 319: ...istributions is the shortest because of inter symbol interference and the many 3T widths The spacing is 138 ns To measure the spread of widths for the distributions set the measure mode to My Measure and configure the parameters 1 P2 average of F2 2 P3 high of F2 3 P4 low of F2 4 P5 range of F2 Because parameter measurements are performed only on those portions of the waveform between the paramete...

Страница 320: ...he actual event time it can be used as the X axis in an XY plot to examine modulation characteristics of particular parameter measurements Example This example typifies the usage of the t pit parameter Step by step instructions are given A large optical recording waveform is to be acquired and the ordinary pit space widths that can cause errors in the system need to be found The waveform contains ...

Страница 321: ... the time at each pit from the trigger is ascending The trend of the pit widths looks basically as expected Notice that there are exactly as many events inside both trends a necessary condition From the menu bar select Display Setup and set the grid mode to XY Bands of pit widths corresponding to widths that are ideal integer multiples of the clock period will be evident Select F2 the trend of t p...

Страница 322: ...rm using the horizontal zoom control Here is the waveform zoomed in a bit with the measurement cursor placed at 859 600 Ps As can be seen there is some kind of aberration at the center of the trace Further zooming clearly identifies the problem a burst error that prevented the positive polarity width that starts at 859 61 Ps from reaching its peak value This defect caused the reflectivity to drop ...

Страница 323: ...togram of the overall timing jitter values calculated for each acquisition for all acquisitions since the last CLEAR SWEEPS operation Trend Function Trend of the overall timing jitter values calculated for each acquisition for all acquisitions since the last CLEAR SWEEPS operation Example A waveform is acquired with 3T 4T and 5T pit widths as follows 3T 4T 5T 695 ns 925 ns 1 16 Ps 690 ns 1 18 Ps 6...

Страница 324: ...ng jitter displayed for each nT distribution Overall timing jitter is calculated by subtracting the mean width of each distribution from the widths in those distributions and considering the resulting superposition The sigma of the 3T 4T and 5T distributions are what is obtained when the Timing Jitter custom parameter is configured for single n values the sigmas are the same as the sigma of the ed...

Страница 325: ...device or comparator typically solves other threshold problems as well in systems that dynamically adjust the threshold based on the optical recording data signal Sliced or logic signals facilitate the use of a fixed threshold Coupling DC coupling is required only for measurements of absolute DC values Measurements requiring it include ptop pbase pmin pmax and pmoda Otherwise AC coupling is best u...

Страница 326: ...escription how the ORM parameters have certain unique characteristics that make particular measurements useful when trended together with XY plots And how the t pit parameter is essential to those measurements Plots that can be generated on single acquisitions include those listed in the table at left The reason that these plots are considered useful on single acquisitions is because the parameter...

Страница 327: ...d and the waveform acquired The waveform should be centered on the screen The trends will typically have data not well centered or off screen These traces can be positioned on the grid by touching the FIND SCALE button in each trend setup dialog The screen shown here is what each trace looks like after the waveform has been acquired and the trends centered The waveforms are displayed in Quad grid ...

Страница 328: ...cy can be improved by considering certain items pertaining to how a DSO operates and how parameters are measured DSOs sample the signal building a waveform that consists of points at intervals determined by the sample rate One obvious consideration for maximizing horizontal measurement accuracy is to ensure that the highest sample rate possible is used On low time divs waveforms become long Thus i...

Страница 329: ...lculation The base and top are designed to emulate results in the past obtained from persistence plots In general the top was calculated by examining the most intense region near the top of a waveform in an eye pattern persistence map The AORM package improves on this in that the tops of all pits are calculated independently rogue amplitude variations in the waveform can be identified The waveform...

Страница 330: ...r 0 1 V bin Events falling into the first bin would then be between 1 5 V and 1 6 V The next bin would capture all events between 1 6 V and 1 7 V And so on After several thousand events the graph of the count for each bin its histogram provides a good understanding of the distribution of values Histograms generally use the X axis to show a bin s sub range value and the Y axis for the count of para...

Страница 331: ...cquisition Because updating the screen can take significant processing time it occurs only once a second minimizing trigger dead time under remote control the display can be turned off to maximize measurement speed Histogram Parameters Once a histogram is defined and generated measurements can be performed on the histogram itself Typical of these are the histogram s x Average value standard deviat...

Страница 332: ...ange difference between highest and lowest data values sigma standard deviation of the data values in histogram totp total population in histogram xapk x axis position of specified largest peak Zoom Traces and Segmented Waveforms Histograms of zoom traces display all events for the displayed portion of a waveform between the parameter cursors When dealing with segmented waveforms and when a single...

Страница 333: ... bins that may make determination of peaks difficult The oscilloscope s parameter buffer is very effective for determining the optimal number of bins to be used An optimal bin number is one where the change in parameter values is insignificant and the histogram distribution does not have a jagged appearance With this buffer a histogram can be dynamically redisplayed as the number of bins is modifi...

Страница 334: ...elay variation for frequencies 6 5 MHz must be 3 ns and gain at 5 0 MHz minus gain at 0 Hz must be 3 2 0 3 dB For the LPF it gives an example implementation to achieve these characteristics as a 6th order Bessel filter with a cutoff frequency fc 3dB 8 2 MHz and an example for the EQ is a three tap transversal filter The OData function implements the 6th order Bessel filter as a FIR filter to provi...

Страница 335: ...ter cutoff frequency The default values for cutoff frequency 8 2 MHz and boost 3 2 dB are the correct settings for 1x DVD and DVD R x Leveled The data is fed to a 1st order integrating low pass filter whose bandwidth is set by Slicer BW in the Equalizer and PLL dialog The default slicer bandwidth 5 0 kHz is correct for 1x DVD and DVD R The output of this filter is subtracted from the waveform to m...

Страница 336: ... delayed as it would be by an analog filter We compensate for the known delay through the digital filter and replace each input point with the corresponding equalized point 4 The FIR LP filter plus 3 2 dB boost from the three tap EQ filter produces the transfer function shown in the next figure when the FIR fc is set to 8 2 MHz The highest peak is 20 log dB magnitude The bowed trace below it is th...

Страница 337: ...r the reasons previously explained Sliced The slicer uses a fixed hysteresis around zero which corresponds to half a division and 1 4 division when not vertically zoomed Remember that the slicer works on Leveled data so zero is the correct threshold the dynamically computed threshold has already been subtracted This means a peak must cross zero and exceed it by a quarter of a division or it will b...

Страница 338: ...ck waveform from the data by passing it through a software PLL This output may be overlapped on the display with Leveled or Sliced output on another trace and it can be used for measurements of the clock frequency If the JTA option is present a JitterTrack of Frequency of the extracted clock may give interesting insight into timing variation in the input signal The only user set parameter for cloc...

Страница 339: ...26 16 8 2 to six significant digits That is correct for DVD according to the specification however it may not be within 0 1 for a real drive Experience shows that drives read a couple of percent fast To make the clock extraction successful the scope must be successful in finding the starting frequency from the data Here are some things you should do to make this successful 1 Capture as clean a sig...

Страница 340: ...ns We can extract the clock from DVD data at 500 MS s 19x 1 GS s 38x and 2 GS s 76x At 250 MS s 9 5x and at 4 GS s 153x it sometimes does not find the right starting frequency Following are some interesting pictures to show what can be handled Figure 5 13 A small section of a 1 ms long noisy DVD waveform Acquired with an ungrounded AP020 probe at 500 MS s Figure 5 14 Same piece of the same signal ...

Страница 341: ...r division How the Starting VCO Frequency Phase Are Determined The PLL s VCO is started at a frequency of 1 T Due to the accuracy required T is determined in two steps The first step produces an estimate of T starting with very few assumptions The second step starts with the estimate of T and refines it The information used in both steps is the sample at which a transition through zero occurred in...

Страница 342: ... JitterTrack shows this clearly On a 4x DVD waveform we captured which just happens to have a significantly out of place first edge the frequency is disturbed slightly for the first 15 μs or so the frequency shift during this time is very small on the order of 0 1 as the phase adjusts Introduction to 8B 10B The new LeCroy Serial Bus Analyzer SBA option key features x Powerful search capability all...

Страница 343: ...rm requires the capture of the waveform in a real time or sampling oscilloscope followed by parsing of the digital data in 10 bit increments until certain characters symbols are detected For example SAS utilizes K28 3 and K28 5 as primitive delimiters x K28 3 1st character of all primitives except ALIGN x K28 5 1st character of ALIGN primitive Here are the rest of the primitives defined in the spe...

Страница 344: ...Recommended System Configuration x SDA DDA or WaveMaster 4000A 4020 6000A 6020 or SDA11000 real time digital storage oscilloscope x X Stream firmware version 4 7 or newer x At least one Serial Data Standards package for example SDA SATA or SDA PCIE G2 Option Key Installation When ordered as an option for a new instrument no installation is necessary Installation is required however when the option...

Страница 345: ...b s 5 Select a Symbol File This text txt file contains the symbol sequence for each primitive command applicable to the waveform under study There is a primitive file for each serial data standard The Protocol field will be updated with the symbol file loaded When no Symbol File has been selected the generic 8b10b name will be displayed Searching for a Symbol or Hex Equivalent 1 Select Analysis fr...

Страница 346: ...om the menu bar select Analysis then Serial Bus SBA from the drop down menu 2 Touch the Export Setup tab The following menu is displayed 3 Select an Export File By default the output file will be created in D Applications SBA directory Or Browse to create a csv comma separated values file by entering a name using the pop up keyboard 4 Select a Script File The default script file is called Exportda...

Страница 347: ...mple would be a toggle between two setups Rings of three or more setups are possible as are trees or any other topology that you need Basic mode also allows you to recall VBScripts that can set up all or part of the scope and do many other things Another more powerful feature is the PlugIn which allows you to add your own ActiveX controls to a setup These controls are powered by routines written i...

Страница 348: ...urthermore they will appear automatically each time the DSO is powered up Editing a CustomDSO Setup File If the file does not exist touch the Editbutton a dialog will appear for you to create the file If the file does already exist the Edit button enables you to modify it The Edit button allows you to edit the file that is named in the Setup file to recall field and not the file of the setup that ...

Страница 349: ...n mark is a VBS comment and causes no action The text in red contains the path and name of the setup file associated with the numbered button This setup will be called when the button is pressed The boolean in blue decides whether the action button will invoke the setup or remain inactive For example in setup B A lss and C lss can be invoked but not B which is already in place As you see from the ...

Страница 350: ...veX control or graph Creating a CustomDSO PlugIn Follow these steps to create an example Visual Basic PlugIn 1 Start a new VB project Select ActiveX Control from the New tab 2 Resize the control A In the Properties window set Width 11940 B In the Properties window set Height 2475 3 Place two buttons on the control A Double click on the command button at left of screen left arrow below B Move and r...

Страница 351: ...op button in Visual Basic B Select Make Project1 ocx from the File menu 7 Install the PlugIn in the instrument A Start the instrument B Select ActiveDSO in the Analysis Menu C Select PlugIns mode D Type Project1 UserControl1 in the COM ProgID of Plug In text box E Click the Install button under the text box 8 Now Click the new Auto and Single buttons to see their effects Properties of the Control ...

Страница 352: ...WavePro 7Zi 351 WP700Zi OM E RevA In the next example you can see a command button a picture box a list box and a Tabbed Dialog Control ...

Страница 353: ...ss to it right click in the tool box at left but not on an icon You will see this menu Now select the Microsoft Tabbed Control as shown below and click on Apply The control will be added into the toolbox at the left of the screen where you can double click on it as usual The new control is shown below arrow ...

Страница 354: ...Grids The example assumes that the instrument is in dual grid mode and that there are at least two visible traces The routine looks for the visible traces in the order C1 C4 F1 FxThe number of math traces available depends on the software options loaded on your scope See Specifications and it exchanges the first two it finds whenever the button is pressed Note that arrays of objects can be constru...

Страница 355: ...id YT1 End If End If Loop Until trace 12 Or views 2 Show the parity of the last swap If Command1 Caption Swap A Then Command1 Caption Swap B Else Command1 Caption Swap A End If Dim TextString As String TextString Text1 Text Dim TextValue As Integer TextValue Val TextString 1 TextString Str TextValue TextString Trim TextString Text1 Text TextString End Sub This routine exchanges the first two trace...

Страница 356: ...n any routine where numerous operations such as triggers have to be performed In fact the caption of the button could have been used to show the number of operations ActiveX offers a large range of standard controls including list boxes for selection from a list and picture boxes for drawing graphs and charts ...

Страница 357: ...ent instrument setups in the second the FFT was zoomed vertically The graph has a red line to represent the theoretical envelope for the peaks This has great potential for testing the transmission characteristics of amplifiers and filters since the output can be compared with a theoretical curve Furthermore if the output is divided by the curve the result for a perfect DUT would be a horizontal li...

Страница 358: ...variables Dim Top Bot As Single Top WM Math F1 Out Result VerticalFrameStop Bot WM Math F1 Out Result VerticalFrameStart Picture1 Scale 0 Top Samples Bot Dim Wave Wave WM Math F1 Out Result DataArray Dim Black White Blue Red As Long Black 0 White HFFFFFF Blue HFF4444 Red HFF Draw a theoretical curve for the peaks StartPoint Top 20 EndPoint 54 5 Picture1 Line 0 StartPoint Samples EndPoint Red Draw ...

Страница 359: ...ry The Solution At present these needs are addressed in two ways One way is building analog filters and placing them in front of the oscilloscope providing an already filtered signal to the DSO The disadvantages of this approach are many Analog filters depend heavily on the accuracy and stability of analog components Although in some cases analog filters are easily implemented they are quite impra...

Страница 360: ...ng to the Parks MacLellan algorithm described in Digital Filter Design and Implementation by Parks and Burrus John Wiley Sons Inc 1987 and then adjusted by windowing the start and end 20 with a raised cosine for improved time domain characteristics and better ultimate rejection in the frequency domain slightly increasing 1st stop band ripple height Low pass Filter Low pass filters are useful for e...

Страница 361: ...asing attenuation Band 5 Second Stop Band signal highly attenuated Band stop Filter Band stop filters are useful for eliminating a narrow band of frequencies Sample applications include medical equipment such as ECG monitors where the dominant ripple at 50 60 Hz is rejected leaving the low energy biological signals intact Digital troubleshooting the inherent frequency of the switched power supply ...

Страница 362: ...er minus half width to corner plus half width attenuation increases with frequency with a rolloff shape of 0 5cos a 0 5 where a ranges from 0 to p over the transition region This region is determined by b which is specified as a percentage of the corner frequency Band 3 Stop Band above corner frequency plus half width highly attenuated The impulse function for the raised cosine filter is Raised Ro...

Страница 363: ...and for Gaussian filters However the BT value a fraction of the symbol frequency determines the filter s width where B half power bandwidth T bit or modulation period IIR Filters Infinite Impulse Response IIR filters are digital filters that emulate analog filters The four types offered by the DFP2 option are as follows x Butterworth x Chebyshev x Inverse Chebyshev x Bessel The Butterworth or maxi...

Страница 364: ...p Multirate Filters Custom Filters Filter Specifications Filter Setup DFP Filter Setup 1 Touch Math in the menu bar then Math Setup in the drop down menu 2 Touch the Fx tab F1 for example for the math trace you want to display your filtered waveform 3 Touch the Single function button if you want to perform just one filtering function on the trace or touch the Dual function button to perform math o...

Страница 365: ... of coefficients If you selected IIR touch inside the Type field and choose an IIR filter type Then touch inside the Stages data entry field and enter a value using the pop up numeric keypad Alternatively you can touch the Auto Length checkbox the Stages field is grayed out and the scope calculates the optimum number of stages 9 Touch the Frequencies tab 10 Depending on the class FIR IIR and kind ...

Страница 366: ...ransfer a filter to the scope check 0 987 This is the DC gain of the filter Now create an ASCII file containing the coefficients FirFilter txt Writing Data to a Data File To write values from Mathcad version 11 to a data file you can use the File Read Write component as follows 1 Click in the blank spot in your worksheet 2 Choose Insert Data File Output from the menu 3 This opens the File Options ...

Страница 367: ...he name of the variable When you click outside the component the values in the Mathcad variable will be written to the filename you specified Each time you calculate the worksheet the data file is rewritten On the instrument when the Custom filter kind is selected a file selection box will appear Select the file saved from Mathcad the coefficients will be used in the filter Example 2 Creating an I...

Страница 368: ...598096189 0 0609096342883086 0 275707942472944 Writing Data to a Data File To write values from Mathcad to a data file you can use the File Read Write component as follows 1 Click in the blank spot in your worksheet 2 Choose Component from the Insert menu 3 Select File Read or Write from the list and click Next This launches the first part of the File Read or Write Setup Wizard 4 Choose Write to a...

Страница 369: ...hs as compared to standard single rate filters This can be achieved in two or more simple steps First a filter with a relatively limited edge frequency is applied and the results are decimated Then a second filter is applied to the decimated waveform substantially reducing the lower edge frequency limit Example A sine wave with a frequency of 3 MHz has a higher frequency noise component A low pass...

Страница 370: ...e test would then have a selection for which pulse to measure and the ET PMT software will automatically find only those pulses The ET PMT package supports the following ANSI and ITU standards ANSI T1 ITU T DS1 E1 twisted pair DS3 E1 coax STS 1 E2 STS 3E E3 E4 STM 1E In addition to these standards It is also possible to define modified or custom pulse mask tests Compatibility The functions of ET P...

Страница 371: ...to the table below The Electrical Telecom adapters listed in the table are available from LeCroy in the TF ET test fixture kit Telecom Standard Required Termination LeCroy Adapter E1 TP 120 ohm AP120 E1 coax 75 ohm PP090 E2 75 ohm PP090 E3 75 ohm PP090 E4 75 ohm PP090 STM 1E 75 ohm PP090 DS 1 100 ohm AP100 DS 3 75 ohm PP090 STS 1 75 ohm PP090 STS 3E 75 ohm PP090 Test Setup Setup The Setup button a...

Страница 372: ...tion contains a set of check boxes that determine what actions are taken when a test fails Actions are selected by checking the appropriate box multiple actions are possible for each failure The available actions are Save Stores the failed waveform in a file When this option is selected the Save Waveform tab appears in the main dialog Touch this tab to set the file name and storage location Stop S...

Страница 373: ...ors on the waveform showing exactly where the measurements are being made Custom Pulse Mask Test Files The pulse mask test file included with the ET PMT software includes the standards listed in the table In addition to these standard pulse masks custom masks can also be created Custom masks include a mask along with pulse alignment criteria and acquisition settings such as waveform averaging and ...

Страница 374: ...dwidth needed to accurately test signal Minimum Sample Rate Minimum sample rate needed to accurately test signal Probe Required probe or adapter left blank if none Type Defines the type of signal and how it will be aligned and tested The choices are x Absolute x Absolute Offset x Relative x Relative Peak Coding Type of coding CMI code mark inversion AMI alternate mark inversion etc used for inform...

Страница 375: ...mit in DIV in the waveform data at which the mask test is stopped This parameter and the one above it allow you to perform mask testing on specific pulses within a longer more complex waveform Mask Data optional Hyperlink to the table that contains the mask data Mask File Name optional Used if MaskData is not specified file name of the custom mask msk file This file type is created by LeCroy s Mas...

Страница 376: ...WavePro 7Zi 375 WP700Zi OM E RevA Absolute Offset Relative ...

Страница 377: ... plots as a function of time the amplitude of the waveform attributes Cycle to Cycle variation Duty Cycle Interval Error Period Width and Frequency Interval Error for example calculates the timing error of a signal compared with an ideal expected interval defined by a user specified reference frequency the most common estimator of jitter The short term variations of a digital signal s significant ...

Страница 378: ...l amplitude Each parameter calculation is performed over all cycles or edges present in the input signal without limitations Statistical Tools The information obtained from applying timing parameters can then be analyzed using the statistical tools histograms and trends x Histograms characterize and present as a bar chart the statistical distribution of a timing parameter s set of values In additi...

Страница 379: ... to its source trace and contains the same number of points as the waveform JitterTrack or Trend Whether it is more appropriate to use JitterTrack or the statistical tool Trend will largely depend on the application as well as the other factors set out in the tables below While JitterTrack sample points are evenly spaced in time those of Trend are not Trend plots any parameter available in the ins...

Страница 380: ...or Data modes for measuring clock signals or data streams Data should be used where available when the pulse widths intervals periods or other significant instants being measured are randomly distributed and contain multiples of the clock period On the one hand apart from jitter clock signals ought to be regular On the other hand data streams by their very nature have irregular pulse widths A cloc...

Страница 381: ...It does this by reducing the jitter range dividing each measurement equal to n u 7 by n Modes CLOCK DATA Jitter Range 37 H H 37 Resolution coarse fine Table 5 1 Comparing a Random Data Stream Analyzed Using Clock and Data Modes Setting Up Jitter Measurements Jitter Math Setup 1 Touch Math in the menu bar then Math Setup in the drop down menu 2 In the Math dialog touch an unused Fx button to simply...

Страница 382: ...r menu closes and the JitterTrack is automatically enabled Jitter Parameters Setup 1 Touch Measure in the menu bar then Measure Setup in the drop down menu 2 Touch the My Measure button 3 In the Measure dialog touch an unused Px button to simply select a jitter parameter from the Select Measurement menu Or touch a Px tab for more setup options 4 Touch the Jitter button in the Select Measurementmen...

Страница 383: ...tude levels horizontally each bin contains a class of similar time values For a Histogram of Use a crossover point in time or in amplitude on an eye diagram Persistence Histogram Vert and Horiz Slices cumulative jitter on an eye diagram Persistence Histogram Horiz Slice signal to noise ratio on an eye diagram Persistence Histogram Vert Slice the different interval widths present in a long data str...

Страница 384: ... slice the units of the center and width of the slice are given in nanoseconds If you choose a horizontal cut the units of the center and width of the slice are given in millivolts How to Trace Persistence A persistence waveform created by turning on persistence is show here rom this waveform you can create three types of shapes on which waveform processing can be performed F Figure 5 28 Figure 5 ...

Страница 385: ...wing the display of analytical results from raw data Typical applications of Persistence Trace are given in this table If you want to Use see edge detail in a fast signal average eliminate noise on a persistence trace average assess typical noise on a persistence trace sigma assess worst case noise on a persistence trace and use it to create a tolerance mask range To Set Up Trace Persistence 1 Tou...

Страница 386: ...opulation of the persistence map can be chosen from which the envelope will be formed enabling exclusion of infrequent events artifacts For each vertical time slice on the persistence map Ptrace Range calculates and plots an envelope corresponding to the map s range The range can then be used in further processing for example as a source for Pass Fail masks Ptrace Sigma Clear Sweeps Scale to stand...

Страница 387: ...s On or use Histogram Width Jitter measure adjacent cycle deviation Dp lv Statistics On or use Histogram Cycle to Cycle Jitter count number of edges in a waveform edge lv measure duty cycle duty lv Statistics On or use Histogram Duty Cycle Jitter measure time interval error tie lv Statistics On or use Histogram Interval Error Jitter measure n cycle n cycle lv N Cycle Jitter measure skew skew Clock...

Страница 388: ...ter parameter The setup dialogs for the Px position open 5 Touch the Measure On Waveforms button if you want to make a direct measurement on the source waveform Or touch the Math On Parameters button if you want to make a measurement on the result of two other parameters that have been added subtracted multiplied or divided If you want to use this feature you must have first set up those other two...

Страница 389: ...erturbations within this band The width of the band is specified in milli divisions Guidelines for Use 1 Hysteresis must be larger than the maximum noise spike you want to ignore 2 The largest value of hysteresis usable is less than the distance from the level to the closest extreme value of the waveform 3 Unless you know the largest noise and closest extreme level that will ever occur on any cycl...

Страница 390: ...ircular parameter buffer of the last 20 000 measurements including values that fall outside the set histogram range If the maximum number of events to be used in a histogram or trend is a number N less than 20 000 the histogram will be continuously updated with the last N events as new acquisitions occur If the maximum number is greater than 20 000 the histogram or trend will be updated until the ...

Страница 391: ...f several peak value bins known with its associated bins as a histogram peak Example A histogram of the voltage value of a five volt amplitude square wave is centered on two peak value bins 0 V and 5 V see figure The adjacent bins signify variation due to noise The graph of the centered bins shows both as peaks Determining such peaks is very useful because they indicate dominant values of a signal...

Страница 392: ...ied by the user In addition depending on the number of bins selected the change in waveform parameter values can be seen In the next figure the histogram shown in the previous figure has been recalculated with 100 bins Note how it has become far less jagged while the real peaks are more apparent Also the change in sigma is minimal 6 750 ps compared with 6 8 ps SDA Overview Serial Data Analyzer Sta...

Страница 393: ...eye pattern testing to these oscilloscopes The option also adds other key components to the basic scope including JTA2 with its TIE lvl parameter TIE lvl is a JTA2 measurement that measures the time interval error of the crossing points of the signal under test and with option SDM also includes a golden PLL clock recovery module that is used for forming the eye pattern without an external trigger ...

Страница 394: ...s Transmitter RapidIO serial 3 125Gb s TX long haul short haul Rx 2 5Gb s TX long haul short haul Rx 1 25Gb s TX long haul short haul Rx SONET OC 1 OC 3 OC 12 OC 48 STS 1 eye STS 3 transmit STS 3 interface SDH STM 1 STM 4 STM 16 PCI Express TX add in transition TX add in de emphasized TX system transition TX system de emphasized RX Serial ATA 1 5 Gb s TX connector RX connector USB2 0 TX near end f...

Страница 395: ... after the first use of the wizard by checking the Don t show me this message again checkbox In this case the dialog will not be displayed until the instrument is restarted The remainder of the jitter setup wizard guides you through a series of dialogs that request input concerning the signal type and measurement method that is desired Explanations of the various choices that can be made are also ...

Страница 396: ...n touch inside the Clock Source field and select a clock input If you want to recover the clock from the signal touch the Recover clock checkbox the Clock Source field will become inactive The Crossing level s section in this dialog allows you to set the voltage level at which the signal timing is measured The crossing level is set separately for the data and clock if an external clock is selected...

Страница 397: ...ositioning of the clock edges relative to the data signal It shifts the clock signal relative to the data signal A clock signal goes through one complete cycle during each bit interval The edge timing can be measured relative to the rising or falling slope of the clock by means of the Clock Slope setting The Tx Density control indicates the ratio of transitions in the data record to the total numb...

Страница 398: ...The Custom selection allows you to select either a first or second order loop response The first order response allows you to select a pole frequency that sets the PLL cutoff and a zero frequency that must be higher than the pole frequency that limits the stop band attenuation The second order PLL allows you to select the natural frequency and damping factor The damping factor determines the trans...

Страница 399: ...htub curve near the edges of the graph where the curves are at their highest amplitude while random jitter determines the shape of the curve near the middle TIE trend This is a trend of the time interval error measurements between the data transitions and the reference clock This is the time record of the information contained in the TIE histogram and TIE histogram A histogram of the time interval...

Страница 400: ...ndards specify several types of masks So a single standard can have a normalized mask and or absolute mask for the transmitter The standard requires you to make sure that the signal passes both the normalized and the absolute masks field allows you to select different modes for the selected standard Individual modes for a given standard define specific masks for example transmit or receive 6 Under...

Страница 401: ...he pop up menu All means that all failures will be shown regardless of where they occur in the eye pattern Near X Y means that if you select a failure marker either by touching the marker on the waveform or by touching the bit number in the Failures list only the subsequent failures near the selected marker will be shown Note The X and Y coordinates indicate the position of the selected failure on...

Страница 402: ...a This prefix will be ignored and only the data will be examined If you selected Size or Size and Header touch inside the Frame size field and enter the number of bytes in the frame using the pop up keypad Frame size divides your waveform into equal pieces of the size that you enter Jitter Setup Jitter measurements are enabled by touching the Jitter button once the signal is set up The Jitter dial...

Страница 403: ... distribution function which forms the sides of the bathtub curve The bathtub curve gives the eye opening or 1UI Tj UI for all bit error rates down to 10 16 The total jitter for a given bit error rate is found by measuring the width of the bathtub curve at the y axis value corresponding to the desired bit error rate The periodic jitter and data dependent jitter are measured directly on the sequenc...

Страница 404: ...the complex sum of the spectral components listed in the table under the Pj breakdown tab DCD Duty Cycle Distortion is the mean difference between the width of positive going pulses low to high to low and negative going pulses high to low to high measured over all pulses in the acquired waveform The widths are measured at the same amplitude as specified for TIE i e not necessarily at 50 of the sig...

Страница 405: ...two constants used to estimate the function Tj BER for very low BER Rje is obtained through the analysis of the growth of the extrapolated histogram of TIE as a function of BER fitting the form Tj BER Dje Tj sigma 1 BER Rje MJSQ Jitter The other method of determining the random and deterministic components is based on the procedure described in the Fibrechannel MJSQ Methods for Jitter and Signal Q...

Страница 406: ...lizing the extrapolated TIE histogram see the Theory section for all possible sampling points within one unit interval UI The right side of the bathtub curve is the integral of the jitter pdf from approximately 1 2 of a UI to zero and the left side is the integral from 1 2 of a UI to zero where the jitter PDF is centered about zero and zero is defined as the ideal crossing time of a bit The bathtu...

Страница 407: ... band pass filter that is applied to the TIE vs time data measured on the signal under test The filtered waveform of the trend of TIE over time is displayed in the waveform grid when Filtered Jitter is selected The filter is implemented as an FIR Finite Impulse Response digital filter with a maximum tap length of 2000 Not all high pass filters are realizable owing to the tap length restriction or ...

Страница 408: ...icient to resolve the tails but more data is always helpful A histogram that appears smooth is a good indicator that the total jitter will be accurate The TIE histogram shows the measured jitter distribution that is the source for the bathtub curve and total jitter parameter 1 Touch the Jitter Histogram button The histogram will be displayed in the center of the bathtub curve 2 Touch the Bathtub b...

Страница 409: ...irst transition in the data pattern D Check the Show Graphic Bit Pattern checkbox to display a trace showing the bit pattern in the grid with the synchronous n cycle plot The transitions of the pattern line up with the measurement points in the plot DDj ISI plot A repeating data pattern is not always present in cases where there is no ability to program the PHY under test There is an alternate met...

Страница 410: ... inside the Data Source field and select a data source 2 The Crossing Level s section in this dialog allows you to set the voltage level at which the signal timing is measured It can be set to either absolute or percent The absolute crossing level in volts or watts for an optical signal can be set directly or can be automatically found by touching the Find Data Level button This level is determine...

Страница 411: ... errors are eliminated in the SDA through the use of the measured transition density in the normalization process The Tx density is automatically measured when the Find Pattern Length button is pressed Edge Edge Jitter Measurements Jitter measurements are enabled by selecting Jitter in the SDA main menu when the mode is set to Edge Edge The available displays include a jitter bathtub curve TIE his...

Страница 412: ...ngle value The bit error rate is selected in the BER pow 10 control in the jitter menu Rj is expressed in terms of an RMS value whereas Tj and Dj are expressed as peak to peak values Dj Deterministic jitter is the peak to peak non random part of the total jitter This parameter is the sum of the measured peak to peak values of periodic jitter Pj and data dependent jitter DDj The DDj includes the ef...

Страница 413: ...hich is determined by the number of UIs in the analyzed signal The HPF Corner Freq readout displays the minimum frequency jitter component that can be measured Edge Edge Spacing Controls The histogram and bathtub curve of TIE measurements are derived by determining the time interval between transitions of the data signal The timing is measured between adjacent edges that are not always 1 UI apart ...

Страница 414: ...ue including all intermediate values or can be synchronous with the transitions in a repeating pattern AltNcycle Control Summary Control Values Description Synch to pattern On off Synchronizes the measurement to a repeating data pattern if present in the signal when this control is checked The timing is measured between the first transition in the pattern and each subsequent transition For an N bi...

Страница 415: ...te The symbol rate of the signal under test This value must be entered by the user in order to set the nominal UI Avg Wfm On off Averages the N cycle plots measured on successive acquisitions This is especially useful for removing random effects from standard deviation plots Use PLL On off Use the software golden PLL to generate the reference clock for edge timing This setting is ignored when DDme...

Страница 416: ...tie histogram This shows the original histogram of TIE measurements that has been extrapolated to a population of 1016 LogTIE The log of the TIE histogram Bathtub The bathtub curve This is a an alternate version of the total jitter curve scaled horizontally to 1 UI The right hand side of the curve is taken from the left hand side of the total jitter curve and the left hand side comes from the righ...

Страница 417: ... lower corner frequency of the band pass filter High Pass Frequency Set by record length and sample rate bit rate The upper corner frequency of the band pass filter Slice2Persist The Include virtual edges checkbox must be checked in the TIE lvl parameter dialog to include both transition and non transition edges in the eye pattern The Slice2Persist function takes as its input a data waveform and a...

Страница 418: ...nd the zero level is set to 2 5 divisions Auto clear sweeps Clears the eye pattern display on each new acquisition Clear Sweeps Clears the current persistence map from the display Scale Top to 4 V to 4 V Scales the one level to a specific voltage on the display Scale Bottom to 4 V to 4 V Scales the zero level to a specific voltage on the display SDA Theory The SDA operates by processing a long sig...

Страница 419: ... a clock at the data rate The computation follows variations in the data stream being tested through the use of a feedback control loop that corrects each period of the clock by adding a portion of the error between the recovered clock edge and the nearest data edge Figure 5 32 Clock Recovery Implementation As shown in Figure 2 the initial output and the output of the digital phase detector are se...

Страница 420: ...tion An eye diagram shows all values that a digital signal takes on during a bit period A bit period or UI is defined by the data clock so some sort of data clock is needed in order to measure the eye pattern The traditional method of generating an eye pattern involves acquiring data on an oscilloscope using the data clock as a trigger One or more samples are taken on each trigger The samples are ...

Страница 421: ... 4 below shows this alignment When mask testing is turned on the entire waveform is scanned bit by bit and compared to the mask When a mask hit is detected the bit number is stored and a table of bit values is generated The table is numbered starting with the first bit in the waveform This table can be used to index back to the original waveform to display the waveform of the failed bit Figure 5 3...

Страница 422: ...The output of the O E is measured with no signal attached i e dark and this value is subtracted from all subsequent measurements Eye Crossing Eye crossing is the point at which the transitions from 0 to 1 and from 1 to 0 reach the same amplitude This is the point on the eye diagram where the rising and falling edges intersect The eye crossing is expressed as a percentage of the total eye amplitude...

Страница 423: ...ignals the relative time between threshold crossings rising to rising or falling to falling is measured Data signals on the other hand generally require the measurement of the relative positioning of the data signal to the sampling clock which is related to setup and hold time Because of its random nature jitter is normally described in terms of its probability density function PDF Figure 5 36 Set...

Страница 424: ...sents these to the user Figure 5 37 Jitter PDF model corresponding to the heuristic in equation 1 The random jitter is modeled by a Gaussian and the deterministic jitter by a pair of impulses separated by the value of the parameter Dj The curve shown is the convolution of Rj and Dj Bit Error Rate and Jitter Equation 1 shows that the total jitter is a function of bit error rate This relationship is...

Страница 425: ...ty of an edge being greater than t or less than t The contribution to the system BER by jitter is given by the probability that an edge occurs at a time greater than t as we mentioned earlier In order to guarantee a BER contribution from jitter below a certain value the positive and negative values of t are chosen so that the probability of an edge at a time greater and less than these times is eq...

Страница 426: ...aken from the right half of the total jitter curve The bathtub curve corresponding to the total jitter curve in Figure 9 is shown in Figure 10 Extrapolating the PDF Measuring the total jitter requires that the probability density function PDF of the jitter be known exactly The SDA measures the jitter PDF by collecting a histogram of TIE measurements The following histogram approximates the PDF by ...

Страница 427: ...n is simply a quadratic curve fit to the extremes of the log of the jitter histogram The extrapolated histogram is used to compute the total jitter curve described above and is normalized so that the sum of the populations of all of the bins is one The integrals described above are implemented by summing the extrapolated histogram bins Separating Rj and Dj Two Methods The total jitter curve is the...

Страница 428: ... the variation of N BER with the log of BER which is approximately linear The values of Rje and Dje are chosen so that the lower curve lies on top of the upper one From equation 1 it can be seen that Rje is a slope parameter while Dje adjusts the intercept point Figure 5 42 The change in total jitter with BER is represented by the values Tjn in the total jitter curve on the left These values are p...

Страница 429: ...e expected data transition times These inserted edges do not add any additional jitter since they are placed at the ideal edge locations for the data rate The trend of TIE is continuous and the spectrum can be computed Periodic jitter is the complex sum of the spectral components excluding those associated with the repetition frequency of the data pattern and its harmonics The deterministic jitter...

Страница 430: ...the bit error rate will indicate 0 5 meaning that exactly of the bits are in error which of course is the worst case Bit Error Map A further level of debugging is available through the bit error map This display is a view of the bit errors in the data stream relative to any framing that may be present in the signal There are several options for framing that may be set The general form of the data ...

Страница 431: ...ould be entirely due to timing jitter but as is often the case things are not so simple All signals contain amplitude noise and this noise can be interpreted as timing jitter in certain circumstances leading to higher overall jitter values The noise on the signal under test is and should be included in any jitter measurement since the data receiver would also interpret this as jitter Any noise add...

Страница 432: ... always Gaussian in nature Furthermore this can be confirmed by in situ calibration procedures How the Measurement System Noise Is Subtracted from the Jitter Measurement The timing noise can be very complex exhibiting periodic jitter Pj and for data streams ISI induced data dependent jitter DDj Other forms of bounded uncorrelated jitter BUj can contribute as well to make the jitter distribution sh...

Страница 433: ...d or binned into adjacent equal width contiguous intervals or bins When the timing errors TIE are collected as a histogram the histogram serves as an approximation to the Probability Density Function PDF of this statistically based phenomenon jitter The PDF is in theory a smooth function determined by the underlying physics of the measured phenomenon and of course what we actually observe includes...

Страница 434: ... consequently 50 of the total population also falls within that bin and those bins with higher index To the point of all of this in telecommunications or data communications the relative rate of bit errors is called BER Sometimes called bit error ratio BER is the relative rate of bit errors compared to the bit rate often expressed as a power of ten For example the BER is ten to the minus 15th Extr...

Страница 435: ...lar remember not to confuse the complementary error function erfc with the inverse error function erf 1 The Relationship between the Inverse Error Function and Total Jitter It is noteworthy that the inverse error function has no closed analytical form It is also noteworthy that the heuristic jitter equation is linearly related to this inverse error function Recall this equation Usually when this e...

Страница 436: ...nalyzing the EDF in order to predict a CDF is best served by a coordinate transformation for the variable BER The subject of Q Scale has been proposed and described by several sources Fibre Channel Methods for Jitter and Signal Quality Specification MJSQ T11 2 project 1316 DT Rev 14 June 9 2004 Jitter Analysis The Dual Dirac Model RJ DJ and Q scale Ransom Stephens Agilent Technologies white paper ...

Страница 437: ...d have a variable normalization factor This normalization is such that when the area of an un normalized Gaussian is norm then that resulting CDF manifests as straight lines with slope revealing sigma and intercept with Q 0 giving the mean of the Gaussian PDF This is the normalized Q Scale where As an example when two different Gaussian distributions are analyzed in this way their EDFs appear as b...

Страница 438: ...f BER are obtained for these variations and an error inversely proportional to the error is assigned to the data point 2 Varying the Q Scale normalization factor over a range of plausible values the best fit to linear behavior is determined 3 Using this value to correctly scale the probability an intercept with Qnorm BER 0 is obtained for both the right hand side and the left hand side of the CDF ...

Страница 439: ...Operator s Manual WP700Zi OM E RevA 438 ...

Страница 440: ...WavePro 7Zi 439 WP700Zi OM E RevA ...

Страница 441: ...re Dj is the separation between the two means of the distributions If the distribution is governed by only two Gaussians of equal weight this equation degenerates into And if in addition the two Gaussians have the same sigma or Rj then This equation is disturbingly different from This is because in the traditional Dual Dirac discussion we typically forget that the two Gaussians are only half stren...

Страница 442: ... It is available with version 4 3 of X Stream software in SDAs and WaveMaster DSOs Its main features are x Three Additional Modes of Eye Diagram display Front Side Bus FSB Application Transition Non Transition Bit Application PCI Express Gated Qualified Eye Diagram x Eye Diagram Measurements available in every mode Amplitude measurements Height Amplitude Zero Level One Level Timing Measurements Ri...

Страница 443: ...tial signals so the use of differential probes is often required to carry out the measurements As with any high speed precision measurements all probes and SMA cables should be calibrated and deskewed prior to any data collection Example Setups FSB Eye Mode Configuration Channel Setup x DataStrobep Channel 1 M1 x DataStroben Channel 2 M2 x Data1 Channel 3 M3 x Data2 Channel 4 M4 Serial Data Analys...

Страница 444: ...re three groups of parameters x Amplitude Eye Height One Level Eye Zero Level Eye Eye Amplitude x Timing Eye RiseTime Eye FallTime x Eye Eye Width Eye RMS Jit Eye BER Eye Crossing Avg Pwr Eye Mask Test Mask Violation Locator Setup 1 Select the Mask Violation Locator tab 2 Check the Testing On checkbox to detect mask violations 3 Check the Show Location checkbox to select display of bits where mask...

Страница 445: ...mple when signal A transition is delayed relative to signal B transition this means that B is the transmitter and A is the receiver The bus clock BCLK signal is formed by a differential pair BCLK0 and BCLK1 running at 533 MHz This is the trigger signal for the bit transactions with the strobe signals as the qualifiers for the actual bit transfers Data Bus Characteristics Refer to the Following Fig...

Страница 446: ... state meaning high voltage on the signal x BCLK is a differential signal Figure 5 51 Common Clock Bus Timing Diagram Intel Corporation Transition Non Transition Eye Diagram A dual display eye diagram is formed with bits that are of non changing polarity non transition and changing polarity transition This display mode is useful for those serial data standards that utilize mask testing for both ty...

Страница 447: ...differ in voltage depending whether it is a transition bit or a de emphasized bit The exact reduced voltage level of the de emphasized bit will always be relative to the transition bit Gated Qualified Eye Diagram The Gated Eye Diagram mode utilizes a separate signal the Gate or qualifier to create dual eye diagrams based on the polarity of the Gate Here s an example of a gated eye diagram Channel ...

Страница 448: ... Figure 5 53 Data M1 and Gate M2 signal sources The following display is the Eye diagram resulting from applying the Gate signal When the Gate is high the bit data goes to one eye diagram When the Gate is low data goes to the other eye ...

Страница 449: ...r Button You can click the Disk Drive Analysis DDA Quick Access toolbar button to display the Drive Analysis setup dialogs DDA Specifications Additional DDA Triggers Sector Pulse Triggers on the nth sector pulse 1 to 50 after index Index and sector pulse polarity and sector pulse number are selectable ...

Страница 450: ... at minimum local time at maximum local time peak trough local time over threshold local time trough peak local time under threshold narrow band phase narrow band power non linear transition shift overwrite pulse width 50 pulse width 50 pulse width 50 resolution track average amplitude track average amplitude track average amplitude x Correlation function x Trend datalog of up to one million event...

Страница 451: ...cations and the margin available before errors occur Head signals for PRML channels have complex waveshapes which are very difficult or even impossible to analyze by visual inspection Analysis of these signals with an oscilloscope is often limited to looking for gross abnormalities such as significant thermal asperities or dropouts of sufficient duration Furthermore because of the sophistication o...

Страница 452: ... equalization with the target values This makes visual interpretation of the quality of the head signal possible and intuitive As a result you can visually inspect the head signal to an extent beyond the more obvious indications of problems such as thermal asperities and dropouts In addition several powerful ways are available for selecting how the section of the equalized annotated head signal wi...

Страница 453: ...gest to smallest order As a general purpose test method Analog Compare can be applied to finding problems in practically any signal including other head signals General Steps of Analog Compare 1 Tell the DDA the signals you are providing Identify in the Channel Setup the signals that are being provided and their source the particular input channel or memory Also identify the section of the head si...

Страница 454: ...t is greater than 1 00 or dominated by residual electronics noise if less than 1 00 Measure s Drive Parameters The buttons accessed via the Measure tab allow quick and convenient setup of the most common sets of measurements made on a head signal These include x Track Average Amplitude TAA PW50 x Amplitude Asymmetry PW50 PW50 Baseline Separation and TAA x Auto Correlation Signal to Noise ACSN x No...

Страница 455: ... then touch Back to complete this setup 11 Touch the Show ML Markers checkbox to enable the markers ML MarkersThe ML Markers indicate the location of the ideal PRML sample values based on the DDA 5005 s channel emulation 12 Touch the Show Level Markers checkbox to enable the markers Level MarkersThe Level Markers indicate the vertical position of the PRML levels based on the amplitude of the acqui...

Страница 456: ...ing the pop up numeric keypad Then press the Measure Bit Cell Time button See Principle of Equalization in PRML Channel Emulation then touch Back to complete this setup 7 Touch inside the VCO synch data field and enter a value from 1 to 32 using the pop up numeric keypad 8 Touch inside the Ignore Last Samples field and enter a value from 0 to 999 9 Touch the Filter head signal checkbox to enable f...

Страница 457: ...al is connected to a DDA 5005 channel and specified it will be used to determine the regions of the signal to be analyzed If Read Gate is not present the entire waveform will be used unless the Analyze Region cursors are enabled 7 If for Read Gate you selected other than none Touch inside the Gate Polarity field and select positive or negative polarity 8 Touch the Store Head Reference button 9 Tou...

Страница 458: ...cy button This action automatically selects parameters msnr rsnr and m_to_r as Source1 in Measure dialog positions P1 to P3 respectively ParamPassThru is the Measure selection made for each which means that the output is the same as the input 9 Touch the Avg Samples checkbox to enable averaging 10 Touch inside the Max Averages data entry field and enter a value from 1 to 32 000 using the pop up nu...

Страница 459: ...umeric keypad Servo Gate Servo Gate triggers on all or selected Servo Gate pulses starting after the Index mark To set it up proceed as follows 1 Press the Disk Drive Analysis DDA button on the Quick Access toolbar The disk drive dialogs appear 2 Touch the Disk Triggers tab 3 In the Disk Trigger Types menu touch Servo Gate The Servo Gate data entry fields appear 4 Touch inside the After index wait...

Страница 460: ...y on which the head signal is to be carried The instrument utilizes the head signal and optionally the Read Gate and the Analyze Region cursors to determine which part of the head signal will be analyzed What follows is an explanation of how the instrument does this and the manner in which it processes the head signal The following figure shows the fields of the head signal and their relationship ...

Страница 461: ...elihood ML Markers signs and Level Markers horizontal lines are displayed in the after picture The ML Markers indicate the location of the ideal PRML sample values based on the DDA s channel emulation The Level Markers indicate the vertical position of the PRML levels based on the amplitude of the acquired PRML signal Selecting the Waveform Section to Be Analyzed For the Analog Compare and Channel...

Страница 462: ...s true is analyzed as shown in sections A B C D and E in Case 2 Case 2 Head Signal Read Gate True regions analyzed If Analyze Region is enabled and Read Gate is not available only the area of the Head Signal within the region is analyzed as shown in Case 3 Case 3 Only the area within the Region is analyzed If neither the markers nor Read Gate are enabled the entire Head Signal is analyzed Case 4 ...

Страница 463: ...sis you should determine which part of the head signal will be analyzed The options you have are to analyze x Part of a single Read Gate cycle x A single Read Gate cycle x Multiple Read Gate cycles There are additional considerations for each of these choices If you choose to analyze a part of a single Read Gate cycle it is important that it include the VCO Synch signal Because it will be difficul...

Страница 464: ...n order to have a stored trace automatically overlapped with later acquisitions This can be done even if the selected channel analysis method does not require a reference or if you do not intend to use the method This might be done just to scroll through waveforms using Auto Scroll to see how well they match Changing the source of the Head Signal or Read Gate invalidates the stored reference You m...

Страница 465: ... is used as a starting guess for analyzing VCO Synch It is also used by Byte offset and Analog Compare to determine how much time a byte occupies and to set the 3 dB frequency of the DDA s equalizing filter if enabled It should be set correctly for the zone being read it does not need to be set on each read within the same zone Changing the bit cell time changes the filter s 3 dB frequency The fil...

Страница 466: ...ns with which it will be compared This means each sector of the reference must be either unsplit or split in the exact same place as the matching sectors in the acquisitions with which it will be compared Channel Emulation without reference must assume that the final surviving sequence of bits is correct and only points out poor quality in the head signal But Channel Emulation with reference has a...

Страница 467: ... signal called the VCO Synch It is required for adjustment of the phase of the PLL phase locked loop which generates the sampling clock as well as adjustment of the AGC automatic gain control Most commonly the VCO Synch is 2T a transition every other bit cell x Bit Cell Time is used as a starting estimate of the VCO Synch signal If the value is not known and the VCO Synch field is at the beginning...

Страница 468: ...on code 3 d is the minimum number of non transitions between transitions When d 0 adjacent transitions are allowed When d 1 adjacent transitions are not permitted For E2PR4 it can also be set to d 2 A non zero d eliminates several possible sequence choices states and transitions in the Viterbi detector If set to 1 when it should be 0 Channel Emulation without Reference will almost certainly detect...

Страница 469: ...his allows the use of either inclusion or exclusion of positions with close to zero SAM which might or might not actually be an error If the threshold is set near 1 only places where the decision to reject the reference bit sequence was made with considerable certainty will appear in the DDA error list If the threshold is greater than zero all the places where Channel Emulation calculates the bit ...

Страница 470: ...e as in the current acquisition 2 It is not possible to compare a reference of one sector to each sector in an acquisition containing many It is not possible to compare a split sector with an unsplit or differently split sector Using Analog Compare This method compares a reference signal to subsequent acquisitions and looks for large changes in the waveform It is a general purpose test method that...

Страница 471: ...reshold to number of divisions mismatch without vertical zoom average over the analysis window is sqrt thresh For example a threshold of 0 015 corresponds to 0 49 of a division average mismatch within the window 2 Analog Compare works best if it can analyze VCO Synch at the beginning of its analysis region for both the reference and the head signal If Read Gate is available it should be able to do...

Страница 472: ...order to avoid such misidentification a hysteresis argument is provided for many local feature parameters This essentially enables you to set a voltage band which a peak trough pair must exceed in order not to be considered noise or a bump The hysteresis setting is also essential to the way peaks and troughs are identified by the DDA The search for local features extends from the left to the right...

Страница 473: ...ithin a band centered around the midpoint of the peak and trough extremes whose height is 2 3 of the peak to trough height If one of the baselines cannot be identified the local baseline is set to the found value If neither baseline can be identified then the local baseline is set halfway between the extremes of the local feature s peak and trough If baselines can be identified on both falling and...

Страница 474: ...atures are recognized Local Parameters The local parameters group offers measurements of common disk drive waveform parameters Local Parameter Definition lbase baseline of local feature lbsep separation between peak to trough and trough to peak baselines lmax maximum value of local feature lmin minimum value of local feature lnum number of local features displayed lpp local feature s peak to troug...

Страница 475: ...he baseline separation for a local feature Description The average value of the separation of the two baselines used to calculate a local baseline is displayed for all local features between the parameter cursors For histograms each individual baseline separation value for all local features between the parameter cursors is provided Parameter Settings Selecting this parameter from the Measure menu...

Страница 476: ...cal feature between the parameter cursors is provided Parameter Settings Selecting this parameter from the Measure menus prompts you for a hysteresis setting which allows you to set the hysteresis value to a specified number of vertical divisions Example lnum Local Number Definition The number of local features in the input waveform Description The number of local features between the parameter cu...

Страница 477: ...resis setting which allows you to set the hysteresis value to a specified number of vertical divisions Example ltbe Local Time Between Events Definition The time between a local feature peak and trough or a local feature trough and the next local feature peak Description Events are defined as either peaks or troughs The average time between successive events in a waveform is displayed as ltbe Prov...

Страница 478: ... prompts you for a hysteresis setting which allows you to set the hysteresis value to a specified number of vertical divisions Example ltbt Local Time Between Troughs Definition The time between a local trough and the next local trough Description The average of the time between successive troughs is determined and its value displayed as ltbt Provided for histograms are the times between successiv...

Страница 479: ...nus prompts you for a hysteresis setting which allows you to set the hysteresis value to a specified number of vertical divisions Example ltmx Local Time at Maximum Definition The time of the maximum value of a local feature Description The time of the maximum value of the first local feature in a waveform after the left parameter cursor is determined and returned as ltmx Provided for histograms a...

Страница 480: ...me Over Threshold Definition The time a local feature spends over a user specified percentage of its peak to trough amplitude Description The peak to trough height of a local feature is measured The time the local feature spends over a user specified percent of the peak to trough height is then determined The average for all local features in a waveform is displayed as ltot Provided for histograms...

Страница 481: ...rcentage of the peak to peak height of the local feature Example ltut Local Time Under Threshold Definition The time a local feature spends under a user specified percentage of its peak to trough amplitude Description The peak to trough height of a local feature is measured The time the local feature spends under a user specified percentage of this height is determined and the average for all the ...

Страница 482: ...amplitude from baseline pw50 pulse width of negative peaks at 50 amplitude from baseline res resolution taa track average amplitude taa track average amplitude of positive peaks from baseline taa track average amplitude of negative peaks from baseline All disk standard parameters except nbph nbpw owrt and p lv make their measurements on waveform peak trough pairs In addition several of the paramet...

Страница 483: ...he waveform trace displayed by the DDA is 960 x 1 frequency or more in length i e the trace is equal to or longer than 960 cycles of a waveform at the selected frequency Otherwise the bin width is 100 integer trace length 1 frequency where integer designates discarding any fractional portions in the result Thus if the waveform trace is 48 5 times longer than 1 frequency the bin width will be 100 4...

Страница 484: ...measurement see nbpw parameter description at LF for both the HF and LF waveforms and subtracting the second result from the first A menu enables the choice of which waveform HF or LF is assigned to which DDA channel or trace 1 2 3 4 M1 to M4 or F1 to F8 The menu button is used to set the input for HF or LF while the input for the selected waveform is set with the associated knob The owrt results ...

Страница 485: ...50 Provided for histograms is the average pw50 value for each local feature between the parameter cursors Parameter Settings Selecting this parameter displays a hysteresis dialog for setting the hysteresis value to a specified number of vertical divisions pw50 Pulse Width 50 Definition The average pulse width at the 50 point between the local feature baseline and the local feature peak Description...

Страница 486: ...Disk PRML Parameters These enable parameter measurements of auto correlation signal to noise ACSN and non linear transition shift NLTS The calculation of both parameters is based on a correlation math function x ACSN can be applied to any periodic waveform Since these waveforms are by definition identical in every period any deviation is due to uncorrelated noise sources By performing an auto corr...

Страница 487: ...e second waveform to its length minus the section length At the upper bound the end of the first waveform section lies at the last sample point of the second waveform Because the length of waveforms in the DDA is limited to 10 divisions the upper bound of the correlation function is 10 divisions minus the section length in divisions acsn Auto Correlation Signal to Noise Definition Provides a signa...

Страница 488: ...of pattern length should work One limitation to know about at this stage the code checks for a reasonable peak The correlation at the center position must be 0 9 or the parameter computation is canceled This is done without the benefit of the parabolic fit but the intent is only to make sure of a reasonable peak The total number of cycles in the acquisition does not affect the ACSN result for a st...

Страница 489: ...ttern length is less than 0 9 the NLTS is not calculated This is because the pattern length sections will be too uncorrelated to provide a meaningful result Otherwise the pattern length value is used to calculate nlts Using the pattern delay value the DDA measures the auto correlation coefficient for the first pattern length chunk of the input waveform with a second pattern length chunk starting f...

Страница 490: ...n each side A curve fit is performed to calculate a better estimate of the true peak height As described above the nlts parameter only requires one waveform Each acquisition must contain only the pseudorandom repeating sequence PRS not a servo wedge or a preamble It does not matter where in the PRS the acquisition begins its echo properties are independent of starting point There must be at least ...

Страница 491: ...a zero crossings and troughs minima Any deviations from the ideal sample points will be a result of noise By performing multiple reads random noise can be averaged away With this measurement the repeating media noise level can be derived by msnr x rsnr can be applied to any single frequency sector based data pattern The single frequency data will be sampled at the peaks maxima zero crossings and t...

Страница 492: ...1 Deviations from the ideal are quantified and graphed The squared sigma of the total noise distribution is equal to the squared sigma of the media noise distribution This relationship is always true t 2 m 2 r 2 For a large number of samples m 2 a 2 r 2 t 2 a 2 Once the distribution of the media noise has been calculated the msnr is then calculated by msnr 20 log v0 p m Parameter Settings After sp...

Страница 493: ...ance improvements are no longer enough Faced with equally impressive advances in semiconductor technology disk drive engineers have been working to create a new read channel architecture that will allow capacity to grow unimpeded The answer lies in the construction of the disk itself The disk s magnetic poles with two orientations possible along the track store the bits as 0 and 1 When the drive r...

Страница 494: ...ault 3 dB frequency then optimizing 3 dB at the better boost Then optimize boost at the new 3 dB frequency and optimize 3 dB frequency again at the new boost And then if 3 dB frequency has changed by more than a small amount optimize the boost one final time The goal for optimization is to maximize the mean of the 100 worst SAM values A typical run will recompute the filter apply it and run the Vi...

Страница 495: ...the setting Group Delay The delay through the filter of the lowest frequencies can be adjusted The normal setting is 0 0 adjustment that is flat response This is used to compensate for group delay distortion before the filter Group delay setting is unaffected by Train Filter The digital implementation of our equalizing filter does not have perfectly flat group delay The non flatness increases with...

Страница 496: ...ctor circuit and is equal to zero in the correct clock position When the signal is correct the error signal is equal to zero and oscillator frequency and phase remain in exactly the correct position If for some reason the phase of the input signal and that of the oscillator diverge owing to instability of disk rotation or noise for example the phase error signal deviates from zero and the frequenc...

Страница 497: ...or 1 0 1 0 0 1 1 0 or 1 0 1 0 0 0 1 1 is easy But which is the most probable The decision is made based on a sequence of samples instead of only a single current sample and the sequence with the minimum distance maximum likelihood is selected as the detection result Viterbi Detector Trellis The Viterbi detector is a state machine consisting of two distinct parts states and transitions While state ...

Страница 498: ... not implement interleaved ML detection therefore it does not check even and odd sample streams separately for this limit However when the constraints are specified as d k1 k2 one can sum k1 and k2 and use that where k is needed This allows a series of non transitions long enough to unquestionably be an error to be reported as an error However it will not catch all the sequences that would be an R...

Страница 499: ...ents for the preceding keyword When the end of the file is reached the DDA verifies that all required keywords were seen in the file If not the message Missing number required keywords is displayed and the parse is considered canceled Not all keywords are required however we strongly encourage you to use them all in every file The result of omitting most optional keywords is to leave previously se...

Страница 500: ...e maximum change in an expected level due to steering from one sample Setting this value to 1 0 or near that value makes the limit irrelevant The DDA uses 0 0625 for PR4 0 03125 for EPR4 and 0 020833 for E2PR4 If this keyword is not seen its value remains unchanged If this value is never set the default is 0 020833 possible error messages MAX_LEVEL_ADJ must be 0 and 1 0 keyword MAX_PHASE_ADJ argum...

Страница 501: ...yword is not seen its value remains unchanged If it has never been set since power on the default is 4e 11 See notes for PLL_PROP_GAIN above possible error messages PLL_INTEG_GAIN must be 0 and 1e 10 keyword PLL_PROP_GAIN arguments value 0 to 1e 8 required no Notes The value is multiplied by a code difference from the expected level times slope normalized to codes bit cell near the sample The resu...

Страница 502: ...format that is 0 and 1 are the two polarities of magnetization On the head signal the first sample of a negative going pulse begins a 0 polarity region on the media and a positive going pulse begins a 1 polarity region from 0 means the bit cell which is no longer part of the state was 0 polarity Consider the state 0011 If the preceding state was 0001 then the state 0011 was arrived at along the fr...

Страница 503: ...changed If it has never been set since power on the default is 6 CAUTION Increasing the steering latency increases the delay for the steering control loops and may make them unstable For a 16 state signal such as E2PR4 the detector uses the sample at STEERING_LATENCY into the trellis and four more preceding it that is further into the trellis to determine the expected value for the sample at STEER...

Страница 504: ...ord ZERO_CROSS_TO_SAMPLE arguments value 0 to 0 5 required yes Notes This tells the DDA how the correct sampling times relate to zero crossings during the VCO synchronization preamble The value is a fraction of the spacing between zero crossings Example The VCO synch is normally a 2T pattern For PR4 the samples are 1 1 1 1 there are two samples between zero crossings and the first sample after a z...

Страница 505: ...VELS 1 66667 33333 0 33333 66667 1 PLL_PROP_GAIN 1e 9 PLL_INTEG_GAIN 4e 11 MAX_PHASE_ADJ 0 04 STEERING_LATENCY 6 TRELLIS_LENGTH 81 AGC_GAIN 0 12 MAX_LEVEL_ADJ 20 833e 3 ZERO_CROSS_TO_SAMPLE 0 25 Fraction of zero cross spacing End of file TF DSQ Overview Probe Calibration with the TF DSQ Fixture The TF DSQ fixture is used in conjunction with the scope software to perform probe deskew and DC calibra...

Страница 506: ...s accomplished with the TF DSQ fixture by following the basic steps in the flowchart at left It is recommended that you read the instructions presented here in their entirety to familiarize yourself with the advanced features of the TF DSQ fixture The combination of TF DSQ fixture and scope software is designed with an important use model Connecting probes to the circuit under test can be a diffic...

Страница 507: ...e TF DSQ fixture comes in a soft case containing the following components x The TF DSQ fixture x A 50 ohm cable x A ProLink extender x A CD containing PDF files of manuals for several scope options including the TF DSQ fixture TF DSQ Components TF DSQ Fixture Elements ...

Страница 508: ... Connection The TF DSQ fixture is connected to either an unused scope channel or the external Aux In on WaveMaster scopes input if one exists In other words any scope channel or scope input with a ProLink connector The TF DSQ fixture can be used only on scopes with blind mating adaptor BMA inputs Scope Auxiliary Input with ProLink and BMA Connector Connection of the TF DSQ Fixture to the Scope Inp...

Страница 509: ...oints and the Clip Differential probes are connected with the tip designated V mated to the pad on the fixture and the tip designated V to the pad on the fixture Single ended probes are connected with the probe tip connected to the V pad only and the ground lead optionally connected to ground Solder in probes have their appropriate tips held down to the microstrip transmission line by the clip Sim...

Страница 510: ...WavePro 700Zi 509 WP700Zi OM E RevA Differential Probe Properly Connected to the Fixture Browsing Configuration Differential Probe Properly Connected to the Fixture Solder in Configuration ...

Страница 511: ...tion in the probe calibration menu is organized such that each row represents the information for a given channel and each column represents the calibration information or control for that channel For each channel the information and control provided includes x The channel number in the colored button icon and the probe type that is installed x A Full Calibration button which starts the calibratio...

Страница 512: ...ot be able to determine the proper attenuation values In this situation you should make sure that the proper attenuation is entered in the channel Vertical setup dialog Furthermore the gain entered should be the gain correction applied to the system with the correctly entered attenuation Probe Deskew Information The probe deskew information contains the measured skew between the probe in the speci...

Страница 513: ...on button in the Probe Calibration Menu x Wait a few seconds as the probe is calibrated calibration wizard closes at end of calibration x When the calibration completes remove the probe from the TF DSQ fixture Now you are ready to probe the circuit and perform your measurements If power is interrupted during your measurements reboot the scope and manually recall your settings Advanced Mode Probe C...

Страница 514: ... Common Mode Voltage Selection The TF DSQ fixture will calibrate probes differentially or in single ended mode depending on the type of probe Differential probes allow the common mode voltage component to be applied during the DC calibration for improved calibration accuracy in situations where probe gain or offset correction depends on common mode components See Probe DC Calibration or Differenti...

Страница 515: ...n time between the edges due to propagation delay variations between the fixture cabling and the probe During the deskew procedure the scope triggers on the channel or external input used for the fixture connection and the time from this trigger to the edge on the probe channel being deskewed is calculated This time becomes the skew time for the probe This process is repeated for all of the other ...

Страница 516: ...urements but each probe has a different risetime x Two probes are used for relative time measurements but each signal has a different risetime The first case will be explained with obvious analogy to the second case Often two probes are utilized for measurements where each probe has a different risetime This might occur because you are making a measurement where a reasonably low bandwidth probe ca...

Страница 517: ...olves the calculation of two constants to be applied to waveforms to correct for voltage measurement inaccuracy The two constants are the gain applied multiplicatively and the offset applied additively It is important to distinguish the gain and offset correction from the channel gain determined by the sensitivity control volts division selection or the offset control The sensitivity and offset co...

Страница 518: ...his later Each of the probe tips are connected to two different signals in a circuit The probe measures only the difference between the two probing points with no actual notion of the absolute voltages present In practice differential probes have limitations not only on the difference allowed between the two probing tips but also the absolute voltage allowed This absolute voltage is referenced to ...

Страница 519: ... Sensitivity 50 2 mV 1 V div fully variable 2 9 99 mV div via zoom 1 M 2 mV 10 V div fully variable DC Gain Accuracy 1 5 of full scale Offset Range 50 ProBus Input 750 mV 10 170 mV div 4 V 172 mV div 1 V div 1 M ProBus Input 1 V 2 128 mV div 10 V 130 mV 1 28 V div 100 V 1 3 V 10 V div 50 ProLink Input 750 mV 10 118 mV div 4 V 120 mV div 1 V div 50 ProBus Input 750 mV 10 170 mV div 4 V 172 mV div 1...

Страница 520: ... Acquisition Processing Averaging Summed averaging to 1 million sweeps continuous averaging to 1 million sweeps Enhanced Resolution ERES From 8 5 to 11 bits vertical resolution Envelope Extrema Envelope floor or roof for up to 1 million sweeps Interpolation Linear or Sin x x Triggering System WavePro 715Zi SDA WavePro 725Zi SDA DDA WavePro 735Zi SDA WavePro 740Zi SDA DDA WavePro 760Zi Modes Normal...

Страница 521: ...s a window defined by adjustable thresholds SMART Triggers State or Edge Qualified Triggers on any input source only if a defined state or edge occurred on another input source Delay between source is selectable by time or events Qualified First In Sequence acquisition mode triggers repeatably on event B only if a defined pattern state or edge event A is satisfied in the first segment of the acqui...

Страница 522: ...1 25 Gb s Typical Low Speed Serial Protocol Triggering Optional Available I2 C SPI SPI SSPI SIOP UART RS232 CAN LIN FlexRay Reference individual datasheets for complete specifications Color Waveform Display Type Color 15 3 flat panel TFT Active Matrix LCD with high resolution touch screen Resolution WXGA 1280 X 768 pixels Number of Traces Display a maximum of 8 traces Simultaneously display channe...

Страница 523: ...upport to synchronize to precision internal clocks Internal Waveform Memory 4 active waveform memory traces M1 M4 store 16 bit point full length waveforms Waveforms can be stored to any number of files limited only by the data storage media capacity Setup Storage Front Panel and Instrument Status Store to the internal hard drive or to a USB connected peripheral device Interface WavePro Z10Zi WaveP...

Страница 524: ...robe System ProBus and ProLink on 4 and 6 GHz models Automatically detects and supports a variety of compatible probes Scale Factors Automatically or manually selected depending on probe used Calibration Output 1 kHz square wave 1 Vp p typical output to probe hook Power Requirements Voltage 100 240 VAC 10 at 50 60 Hz 100 120 VAC 10 at 400 Hz Automatic AC Voltage Selection Max Power Consumption 800...

Страница 525: ...m 14 x 18 4 x 11 4 height excludes feet Weight 18 4 kg 40 lbs Shipping Weight 26 6 kg 58 lbs Certifications CE Compliant UL and cUL listed conforms to EN 61326 EN 61010 1 UL 61010 1 2nd edition and CSA C22 2 No 61010 1 04 Warranty and Service Three year warranty calibration recommended annually Optional service programs include extended warranty upgrades and calibration services ...

Страница 526: ...ontact corp lecroy com Web Site http www lecroy com Europe Phone Sales 41 22 719 2228 Fax Sales 41 22 719 2230 Email Sales contact sa lecroy com Web Site http www lecroy com europe China Phone Sales 86 28 86527180 7181 7182 Fax Sales 86 28 8652 7183 Email Sales george ni lecroy com Singapore Phone Sales 65 64424880 Fax Sales 65 64427811 Email Sales jimmy ong lecroy com TaiwanPhone Sales 886 2 8226...

Страница 527: ...power switch When it is pressed the oscilloscope s state toggles between operating and Standby mode This switch is not a disconnect device The instrument can only be placed in a complete Power Off state by flipping the main power switch to the off Zero position This symbol is used to denote Alternating Current CAUTION The CAUTION sign indicates a potential hazard It calls attention to a procedure ...

Страница 528: ...y dry non conductive pollution occurs Occasionally a temporary conductivity caused by condensation must be expected Protection Class 1 refers to a grounded equipment in which protection against electric shock is achieved by Basic Insulation and by means of a connection to the protective ground conductor in the building wiring PLEASE NOTE THE FOLLOWING The design of the instrument has been verified...

Страница 529: ...power cord from the AC supply The oscilloscope should be positioned to allow easy access to the socket outlet Disconnect the oscilloscope from the AC supply by unplugging the instrument s power cord from the AC outlet after the oscilloscope is placed in Standby state CAUTION The outer shells of the front panel terminals CH1 CH2 CH3 CH4 AUX IN AUX OUT are connected to the instrument s chassis and t...

Страница 530: ...libration should be performed by qualified personnel only Cleaning Clean only the exterior of the instrument using a damp soft cloth Do not use chemicals or abrasive elements Under no circumstances allow moisture to penetrate the instrument Avoid electrical shock hazard by unplugging the power cord from the AC outlet before cleaning WARNING Electrical Shock Hazard x No operator serviceable parts i...

Страница 531: ...of base top 485 CAV 407 choice of signals 478 clock hysteresis 415 Clock setup fields 414 Clock Slope field 415 Clock Source field 415 configuration menus 426 configuration options table 425 coupling 479 Data fields 413 Data Gate field 413 data hysteresis 414 Data Slope 414 Dp2c parameter 443 Dp2cs parameter 445 DSO process 488 DVD processing model 493 DVD RAM 494 EDGSH parameter 446 EES parameter...

Страница 532: ...r 496 slicer bandwidth 418 slope clock 415 slope data 414 Source field 413 Subject nT field 415 T PIT parameter 471 theory of operation 487 Threshold selecting a 480 TIMJ parameter 474 To nT field 415 trend function 421 calculation 423 example 482 reading 423 setup 421 Trend menu selection 417 Units menu 413 View menu 417 view modes 424 XY Plot menu selection 417 ZCLV 407 zoom traces 490 apparent ...

Страница 533: ...Excel sheets organizing 97 exponential decay time constant 107 gated parameter 109 multiple inputs and outputs 100 multiple traces 112 surface plot 114 trace descriptors 99 golden waveform VBS example 86 MATLAB 128 control panel 130 function editor 131 parameter call 134 parameter control panel 135 parameter editor 136 parameter panel example 137 waveform function call 129 waveform function exampl...

Страница 534: ...setup 141 Displaying an Individual Segment 30 279 Dj effective parameter 242 dov parameter 242 Dperiod level parameter 242 droop fg parameter 243 droop hj parameter 243 dropout trigger 368 DSO process 160 Dtime level parameter 243 Dtrig time parameter 243 Dual Channel Acquisition 44 duration parameter 243 duty cycle parameter 243 duty level parameter 243 Dwidth level parameter 243 E ecc 680 EDF 63...

Страница 535: ...ve port 207 features 507 fft algorithms 214 fft filters 216 fft glossary 216 fft setup 210 least prime 210 power of 2 210 truncate 210 zero fill 210 fft theory 211 aliasing 216 choosing a window 212 coherent gain 216 dynamic range 212 enbw 216 filters 216 frequency bins 216 frequency resolution 217 leakage 211 memory 211 Nyquist frequency 217 picket fence scallop 211 picket fence effect 217 pitfal...

Страница 536: ...7 histogram parameters optional 161 histogram peaks 162 histograms creating and viewing 158 histicons 159 persistence 159 range 160 slice center 159 theory 160 thumbnail 159 histograms and PDF 637 hold time parameter 249 holdoff 376 hparam script parameter 249 hysteresis 697 and local features 686 factors 688 I IIR filters 538 installation 511 Intensity knob 283 intensity of grid 141 intensity of ...

Страница 537: ...een peaks 692 local time between troughs 692 local time over threshold 694 local time peak to trough 694 local time trough to peak 695 local time under threshold 695 local tmax parameter 250 local tmin parameter 250 local tot parameter 251 local tpt parameter 251 local ttp parameter 251 local tut parameter 251 locking of persistence traces 157 logic trigger 356 LPA LeCroy ProLink Adapter 57 81 M m...

Страница 538: ...rameter math 232 parameter script 232 quick access 225 standard horizontal 231 standard vertical 231 statistics 230 status symbols 228 turning on 225 X Stream browser parameter status 228 partitions hard disk 272 pass fail setup 61 pass fail testing 61 actions 61 setup 61 pattern delay 705 pattern length 703 acsn 703 nlts 704 pattern period 705 pattern time parameter 253 pattern trigger 356 PCI Ex...

Страница 539: ...r 353 R random nrz 562 range parameter 173 248 read gate 673 683 and analog compare 685 real power parameter 255 recalling default scope settings 284 recalling scope settings 284 reference waveform using analog compare 685 remote configuring 382 removable hard drive 180 resample and deskew 194 rescaling 195 resolution parameter 255 700 restoring software 176 retraining filters 678 ring parameter 2...

Страница 540: ... 615 effective Dj 597 effective Rj 597 error function 640 eye mode 590 amplitude 622 average power 623 crossing 622 extinction ratio 622 eyeBER 625 height 622 Q factor 623 violation locator 620 width 622 eye patterns 622 function reference 609 alt n cycle 609 Htie to BER 612 jitter filter 614 HDMI 587 histograms and PDF 637 Htie to BER 612 inverse error function 641 ISI setup 603 jitter filter fun...

Страница 541: ...ew parameter 256 slew rate parameter 257 slice center 159 smart memory 341 SMART triggers 361 dropout trigger 368 glitch trigger 362 interval trigger 364 runt trigger 370 slew rate trigger 372 SNTP 386 software assisted trigger 348 software restoring 176 sparser 202 Spectrum Analyzer 32 ssc diff parameter 257 ssc frequency parameter 257 ssc ratio 257 ssc track parameter 257 Starting TriggerScan 35...

Страница 542: ...ing and viewing 343 trigger coupling 374 trigger modes 374 trigger setup 374 coupling 374 find level 374 high frequency optimization 377 holdoff 376 modes 374 optimization 374 slope 374 source 375 trigger types 345 window slope 375 trigger sources 375 trigger types 345 TriggerScan 34 378 truncate 210 tUpS parameter 258 TxCmD parameter 258 TxFall parameter 258 TxRise parameter 258 U upsample 203 us...

Страница 543: ... 512 WaveML data format 286 WavePro Specifications 743 WaveScan 64 channel view 66 edge mode 70 filter methods 77 filter wizard 76 histograms 68 index table 69 level markers 66 measurement mode 74 non monotonic mode 71 persistence 67 runt mode 72 sampling mode 65 search modes 64 signal views 64 Undo button 68 WaveStream sampling mode 283 Welcome 23 width n parameter 259 width parameter 259 width t...

Страница 544: ...Thank you for purchasing a WavePro SDA or DDA 7 Zi Oscilloscope ...

Отзывы:

Нет отзывов

Бренды по названию

Популярные бренды

Загрузить еще бренды