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–21

FFT Glossary

The following table lists the coefficients

The window

functions seen in the time domain are symmetric around the
point k = N/2.

Coefficients Of Window Functions

Window Type

Rectangular

1.0

0.0

von Hann

0.5

–0.5

0.0

Hamming

0.54

–0.46

0.0

Flat-Top

0.281

–0.521

0.198

Blackman-Harris

0.423

–0.497

0.079

Appendix C References

Bergland, G.D

A Guided Tour of the Fast Fourier Transform

IEEE Spectrum, July 1969, pp. 41–52.
A general introduction to FFT theory and applications.

Brigham, E.O.

The Fast Fourier Transform

, Prentice Hall, Inc.,

Englewood Cliffs, N.J., 1974.
Theory, applications and implementation of FFT. Includes
discussion of FFT algorithms for N not a power of 2.

Harris, F.J.

On the Use of Windows for Harmonic Analysis with

the Discrete Fourier Transform

, Proceedings of the IEEE, vol.

66, No. 1, January 1978, pp. 51–83.
Classic paper on window functions and their figures of merit,
with many examples of windows.

Ramirez, R.W.

The FFT Fundamentals and Concepts

, Prentice

Hall, Inc., Englewood Cliffs, N.J., 1985.
Practice-oriented, many examples of applications.

Содержание 9300C Series

Страница 1: ...Operator s Manual LeCroy 9300C Series Digital Oscilloscopes Revision A January 1998 ...

Страница 2: ... Corp Epson is a registered trademark of Epson America Inc PowerPC is a registered trademark of IBM Microelectronics MATLAB is a registered trademark of The MathWorks Inc DeskJet ThinkJet QuietJet LaserJet PaintJet HP 7470 and HP 7550 are registered trademarks of Hewlett Packard Company I 2 C is a trademark of Philips Manufactured under an ISO 9000 Registered Quality Management System Visit www le...

Страница 3: ...ation 3 1 Chapter 4 Introduction to the Controls The Front Panel 4 1 The Main Controls 4 3 Choosing and Navigating in Menus 4 4 System Setup and Menu Controls 4 6 Screen Topography 4 8 Chapter 5 CHANNELS Coupling and Probes Channel Controls 5 1 Coupling 5 3 Probes and Probe Calibration 5 4 Chapter 6 TIMEBASE TRIGGER TIMEBASE TRIGGER Controls 6 1 Chapter 7 Timebase Modes and Setup Timebase Sampling...

Страница 4: ...thematics and Math Setup Zooming for Precise Waveform Measurements 10 1 Math Functions and Options 10 2 Using Waveform Mathematics 10 5 Configuring for Zoom and Math 10 6 Setting Up FFT Span and Resolution 10 17 Chapter 11 Display Setting Up the Display 11 1 Chapter 12 UTILITIES Printing Storing Using Special Modes 12 1 Hardcopy Setup 12 2 Time Date Setup 12 4 GPIB RS232 Setup 12 5 Mass Storage Ut...

Страница 5: ...lues 14 1 Parameters Automatic Measurements 14 4 Pass Fail Testing 14 13 Chapter 15 PANEL SETUPS Saving and Recalling Panel Setups 15 1 Chapter 16 SHOW STATUS The Complete Picture Summarized 16 1 Appendix A Specifications Appendix B Enhanced Resolution Appendix C Fast Fourier Analysis FFT Appendix D Parameter Measurement Appendix E ASCII Stored Files ...

Страница 6: ...ut warranty of any kind covering detailed performance Products not made by LeCroy are covered solely by the warranty of the original equipment manufacturer In exercising its warranty LeCroy will repair or at its option replace any product returned within the warranty period to the Customer Service Department or an authorized service center However this will be done only if the product is determine...

Страница 7: ... example there might be small discrepancies in the values of components affecting pulse shape timing or offset and infrequently minor logic changes However be assured the scope itself is in full order and incorporates the most up to date circuitry We frequently update firmware or software during servicing to improve scope performance free of charge during warranty We will keep you up to date with ...

Страница 8: ...1 3 billed for parts and labor related to the repair work and for shipping ...

Страница 9: ...at the RAN be clearly shown on the outside of the shipping package for prompt redirection to the appropriate LeCroy department What Comes with Your Scope The following items are shipped together with the standard configuration of this oscilloscope Ø Front Scope Cover Ø 10 1 10 MΩ Passive Probe one per channel Ø ProBus Single Channel Adapter 9354C 9374C 9384C SERIES ONLY Ø Two 250 V T rated Fuses 5...

Страница 10: ...processing is also rapid with data being transferred to the display memory for direct waveform display or stored in the reference memories see below ADCs The instrument s multiple ADC architecture ensures absolute amplitude and phase correlation maximum ADC performance for multi channel acquisitions large record lengths and excellent time resolution Memories The copious acquisition memories simpli...

Страница 11: ... HF REJect HF and DC the slope from positive and negative See Chapter 8 Automatic Calibration The oscilloscope s automatic calibration ensures an overall vertical accuracy of typically 1 of full scale Vertical gain and offset calibration take place each time the volts div setting is modified In addition periodic calibration is performed to ensure long term stability at the current setting Display ...

Страница 12: ...thus ensuring rapid front panel configuration When the power is switched off the current front panel settings are automatically stored for subsequent recall at the next power on The oscilloscope has also been designed for remote control operation in automated testing and computer aided measurement applications operations described in the Remote Control Manual The entire measurement process includi...

Страница 13: ...se 8 bit Flash ADC 8 bit Flash ADC 8 bit Flash ADC 8 bit Flash ADC Fast memory Fast memory Fast memory Fast memory Sample Hold Sample Hold Sample Hold Program memory Microprocessor Storage devices Centronics RS 232 C GPIB Coprocessor Front panel processor Real time clock Data memories Hi Z 50 Amplifiers Attenuators W Display processor ...

Страница 14: ...bit ADC 8 bit ADC 8 bit ADC Fast memory Peak detect Peak detect Peak detect Peak detect Fast memory Fast memory Fast memory Sample Hold Sample Hold Sample Hold Program memory Microprocessor Hi Z 50 Amplifiers Attenuators W Storage devices Centronics RS 232 C GPIB Coprocessor Front panel processor Real time clock Data memories Display processor ...

Страница 15: ...2000 m 6560 ft The oscilloscope has been qualified to the following EN61010 1 category Ø Protection Class I Ø Installation Overvoltage Category II Ø Pollution Degree 2 Safety Symbols Where the following symbols or indications appear on the instrument s front or rear panels or elsewhere in this manual they alert the user to an aspect of safety Symbol Meaning CAUTION Refer to accompanying documents ...

Страница 16: ...ions are understood and met WARNING Any use of this instrument in a manner not specified by the manufacturer may impair the instrument s safety protection The oscilloscope has not been designed to make direct measurements on the human body Users who connect a LeCroy oscilloscope directly to a person do so at their own risk Use only indoors Power RequirementsThe oscilloscope operates from a 115 V 9...

Страница 17: ... with a three wire electrical cord containing a three terminal polarized plug for mains voltage and safety ground connection The plug s ground terminal is connected directly to the frame of the unit For adequate protection against electrical hazard this plug must be inserted into a mating outlet containing a safety ground contact Cleaning and Maintenance Maintenance and repairs should be carried o...

Страница 18: ...4 1 4 Introduction to the Controls Two Channel Front Panel ...

Страница 19: ...4 2 Introduction to the Controls Four Channel Front Panel ...

Страница 20: ...d buttons vertically aligned beside the screen RETURN and the two linked rotary knobs enable on screen menu selection See following pages CHANNELS This group offers selection of displayed traces and adjustment of vertical sensitivity and offset See Chapter 5 AUTO SETUP This singular blue button automatically adjusts the scope to acquire and display signals on the input channels See Chapter 6 TIMEB...

Страница 21: ... immediately displayed on screen as a menu group Once accessed these menus are controlled using the menu buttons and the two menu knobs illustrated at left A menu button is active and can be pressed to make selections whenever a menu is visible beside it on screen The two menu knobs work together with the two menu buttons to which they are joined by lines Both control the menus currently shown bes...

Страница 22: ...r up or down the list The arrow s direction shows whether the highlighting selector will move up or down Arrows may also indicate items that are not visible either above or below on the list The respective arrow will disappear when the selection is at the very beginning or end of the list As in the examples at left some menu button and knob combinations control the value of a continuously adjustab...

Страница 23: ...in the other control groups are described in the following chapters along with the other elements in the groups The DISPLAY button provides entry to the DISPLAY SETUP group of menus controlling display mode grids intensities Dot Join and Persistence menus See Chapter 11 The UTILITIES button gives access to the UTILITIES menus controlling hardcopy setups GPIB addresses and special modes of operatio...

Страница 24: ...ied However it is possible to copy the waveforms without the grid by turning the grid intensity to 0 with the Display Setup menu While a screen dump is taking place indicated by the on screen PRINTING or PLOTTING message it can be aborted by pressing SCREEN DUMP a second time It will take a certain amount of time for the buffer to empty before copying stops CLEAR SWEEPS restarts operations requiri...

Страница 25: ...tion to the Controls Screen Topography The sections of the screen shown here and described below which surround the grid contain a variety of useful information as well as accessing specific commands and functions ...

Страница 26: ...sed are indicated in the Displayed Trace label above Trigger Level arrows on both sides of the grid that mark the trigger voltage level relative to ground level Trigger Delay an arrow indicating the trigger time relative to the trace The delay can be adjusted from zero to ten grid divisions pre trigger or zero to 10 000 post trigger off screen Pre trigger delay appears as the upward pointing arrow...

Страница 27: ...ection from the MEASURE menu group this field displays the time between the cursor and the trigger point Message field used to display a variety of messages above the grid including warnings indications and titles showing the instrument s current status General Instrument Reset Simultaneously press the AUTO SETUP button the top menu button and the RETURN button The scope will revert to its default...

Страница 28: ... and VOLTS DIV controls will then be attributed to this the active channel On two channel models right each channel has its own set of unique dedicated controls SELECT CHANNEL On four channel models right these buttons are used to attribute all the vertical controls to one channel independent of whether or not it is the channel displayed The selected channel number is highlighted in the Acquisitio...

Страница 29: ...the acquisition offset can be chosen from the SPECIAL MODES menu VAR allows the user to determine whether the VOLTS DIV knob will modify the vertical sensitivity in a continuous manner or in discrete 1 2 5 steps The format of the vertical sensitivity in the Acquisition Summary field bottom left of screen shows whether the VOLTS DIV knob is operating in continuous or stepping mode COUPLING menu ent...

Страница 30: ...v and input coupling to display ECL signals Press the button a second time and the settings for TTL signals are given And a third time returns the settings to those used at the last manual setup of the channel Global BWL To turn the bandwidth limit OFF or ON The bandwidth can be reduced from 500 MHz or 1 GHz to either 200 MHz or 25 MHz or 30 MHz 3dB depending on the model see Appendix A Bandwidth ...

Страница 31: ...o the trimmer on the probe s barrel and turning it clockwise or counter clockwise to achieve the optimal square wave contour More On Coupling In the AC position signals are coupled capacitively thus blocking the input signal s DC component and limiting the signal frequencies below 10 Hz In the DC position all signal frequency components are allowed to pass through and 1 MΩ or 50 Ω may be chosen as...

Страница 32: ...Used to select the input channel s coupling If an overload is detected the instrument will automatically set the channel to the grounded state the menu can then be reset to the desired coupling V div Offset When NORMAL is highlighted pressing the corresponding menu button sets the offset Volts div and input coupling to display ECL signals Press the button a second time and the settings for TTL sig...

Страница 33: ...ETUP will operate on all channels switching them all on Signals detected must have an amplitude between 5 mV and 40 V a frequency greater than 50 Hz and a duty cycle greater than 0 1 If signals are detected on several channels the channel with the lowest number will determine the selection of the timebase and trigger source STOP This button halts the acquisition in any of the three re arming modes...

Страница 34: ...scope will sample the input signals continuously and indefinitely The acquisition will have no trigger condition but can be stopped as desired Press AUTO in Sequence Mode and the acquisition will be terminated if the time between two consecutive triggers exceeds a timeout that can be selected The next acquisition is then started from Segment 1 NORM Pressing this button will continuously update the...

Страница 35: ...to 100 of the full time scale in steps of 1 The pre trigger delay is illustrated by the vertical arrow symbol at the bottom of the grid Post trigger adjustment is available from 0 to 10 000 divisions in increments of 0 1 of a division The post trigger delay value is labeled in seconds and is located in the on screen Trigger Delay field ZERO sets the trigger delay at zero the trigger instant at the...

Страница 36: ...6 4 TIMEBASE TRIGGER TIMEBASE SETUP menu entry button that calls up the TIMEBASE menus described in the next chapter TRIGGER SETUP menu entry button that calls up TRIGGER SETUP detailed in Chapter 8 ...

Страница 37: ...s being determined by the trigger delay The time of the trigger event is measured using the timebase clock The horizontal position of a waveform is determined using the trigger event as the definition of time zero Waveform display is also carried out using this definition Because each channel has its own ADC the voltage on each input channel is sampled and measured at the same instant This allows ...

Страница 38: ...ctive sampling rates higher than the maximum single shot sampling rate It is used on repetitive waveforms with a stable trigger The maximum effective sampling rate of 10 GS s can be achieved by acquiring 100 single shot acquisitions or bins at 100 MS s using the 9304C 9310C 9314C Series oscilloscopes 20 bins at 500 MS s when using the other models These bins are positioned approximately 0 1 ns apa...

Страница 39: ... The latest data is used to update the trace display in the same manner as a strip chart recorder Waveform Math and Parameter calculations are done on the completed waveforms Sequence Sequence Mode is an alternative to single shot acquisition that offers many unique features The complete waveform consists of a number of fixed size segments acquired in Single Shot Mode see Appendix A for the limits...

Страница 40: ...quence Mode is normally for acquiring the desired number of segments and terminating the waveform acquisition It can also be used to acquire the segments continuously overwriting the oldest ones as needed with a manual STOP order or timeout condition being used to terminate the waveform acquisition The ADCs can be interleaved to boost standard sampling rate and record length considerably When chan...

Страница 41: ...cessive single shot acquisitions from the input channels This mode allows the capture of non recurring or very low repetition rate events simultaneously on all input channels Ø RIS Random Interleaved Sampling achieves a higher effective sampling rate than Single Shot provided the input signal is repetitive and the trigger stable Sample Clock To select Internal or External ECL OV TTL clock modes se...

Страница 42: ...7 6 Timebase Modes and Setup For selecting the maximum number of samples to be acquired using the associated menu knob See Appendix A for model maximums ...

Страница 43: ...RIG Option ONLY RP Rear Panel specifies that the 50 500 MHz external clock connected to the rear panel be used as the sample clock see CKTRIG Manual for details External To select the input coupling for the external clock signal Sequence Offers Sequence Mode The corresponding knob is used to adjust the number of segments Neither the trigger time stamps nor the AUTO sequence time out feature are av...

Страница 44: ...r and the external clock Therefore successive acquisitions of the same signal can appear to jitter on the screen Ø The oscilloscope will require a number of pulses typically 50 before it recognizes the external clock signal The acquisition is halted only when the trigger conditions have been satisfied and the appropriate number of data points have been accumulated Ø Any adjustment to the time divi...

Страница 45: ...hile when the same selection is made on four channel models either Channels 1 and 2 or 3 and 4 may be combined But when 1 on two channel models or 4 on four channel scopes is selected none of the channels is combined Sequence When either On or Wrap are activated the menu changes to the one shown here The associated menu knob is used to choose the desired number of segments here given in example as...

Страница 46: ...he last n segments will be displayed An alternative way to stop the WRAP sequence is through AUTO mode if the time between two consecutive triggers exceeds a time out that can be selected the acquisition will stop Max segment To select using the corresponding button or associated knob the maximum record length for each segment See Appendix A for model maximums Note A summary of the acquisition con...

Страница 47: ...adjustments are made directly using the front panel controls and with the trigger menus Rotating for example causes the scope to adjust the trigger level of the highlighted trace Pressing accesses advanced trigger operations such as changing the glitch width or the hold off timeout which are changed via the TRIGGER SETUP menu group Fig 8 1 Once the trigger configuration has been modified changes a...

Страница 48: ...es or spikes specific logic states or missing bits A qualification might include trigger generation only on a pulse wider or narrower than a user specified limit Or it might require to take but another example three trigger sources exceeding specific levels for a minimum time Generally speaking SMART Trigger offers various trigger qualifications based on three basic abilities 1 To count a specifie...

Страница 49: ...signal source meets the trigger conditions The trigger source is defined by the trigger level coupling slope or hold off Figure 8 2 Edge Trigger Menu see page 8 9 Edge Trigger on Coupling Slope Pos Neg Window DC AC LFREJ HFREJ HF 1 2 3 4 Ext Ext10 Line Holdoff Off Time 10 ns to 20 s Events 1to 99 999 999 ...

Страница 50: ...hat 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 is normally unchanged when the vertical gain or offset is modified The Amplitude and Range of the trigger level are limited as follows Ø 5 screen divisions with a channel as trigger source Ø 0 5 V with EXT as trigger source Ø 5 V with EX...

Страница 51: ... when needed It will be automatically overridden and set to AC when incompatible with other trigger characteristics as is also the case for SMART Trigger Only one slope is available indicated by the trigger symbol Slope Slope determines the direction of the trigger voltage transition used for generating a particular trigger event Like coupling the selected slope is associated with the chosen trigg...

Страница 52: ... and started on each trigger The hold off timeout should exceed the duration of the signal displayed on screen For instance at a timebase setting of 1 ms div the time out hold off should at least exceed 10 ms Figure 8 3 Edge Trigger with Hold off by Time Hold off time Hold off time Trigger Source Positive Slope Trigger can occur Generated Trigger Trigger Event Trigger Event Trigger Event Trigger i...

Страница 53: ...r of times the trigger condition is met after the last trigger For example if the number selected is two the trigger will occur on the third event Figure 8 4 Edge Trigger with Hold off by Events Holdoff by 2 events Holdoff by 2 events Trigger Source Positive Slope Trigger can occur Generated Trigger Event 1 Event 2 Event 2 Event 1 Trigger Event Trigger Event Trigger Event Trigger initiates hold of...

Страница 54: ...lable Fig 8 5 Two trigger levels are defined and a trigger event occurs when the signal leaves the window region in either direction Figure 8 5 Edge Window Trigger Window Trigger AVAILABLE ONLY WITH 9304C 9310C 9314C SERIES WINDOW REGION Trigger Level Triggers Time Lower Region Upper Region ...

Страница 55: ...hich allows triggering whenever the input signal leaves a specified voltage window defined in the window size menu The window size menu becomes available on models featuring Window Trigger It allows adjustment of the window around a level defined using the Trigger LEVEL knob holdoff To allow the disabling of the oscilloscope s trigger circuit for a definable period of time or number of events afte...

Страница 56: ...tterns Glitch Trigger Glitch Trigger Fig 8 6 is used to capture narrow pulses inferior to or exceeding a given time limit In addition a width range can be defined to capture any pulse that is comprised within or outside the specified range an Exclusion Trigger Figure 8 6 Glitch Trigger Menu see page 8 30 Glitch Trigger on Coupling At end of Neg Pos Pulse DC AC LFREJ HFREJ HF 1 2 3 4 Ext Ext10 Patt...

Страница 57: ...MI telecommunications and magnetic media studies This Glitch Trigger selects a maximum pulse width Fig 8 7 It is generated on the selected edge when the pulse width is less than the selected width The timing for the width is initialized and restarted on the slope opposite to the edge selected Widths of between 2 5ns and 20 s can be selected but typically triggering will occur on glitches 1ns wide ...

Страница 58: ...s will generate the trigger The timing for the width is initialized and restarted on the slope opposite to the edge selected Widths of between 2 5 ns and 20 s can be selected Figure 8 8 Exclusion Trigger Only pulses within or outside the boundaries of the width range are captured Applications Exclusion Triggers allow a signal s normal width or period to be specified with the scope instructed to ig...

Страница 59: ...t In addition a width range can be defined to capture any interval that is comprised within or outside the specified range an Exclusion Trigger by Interval Figure 8 9 Interval Trigger Menu see page 8 32 Applications Interval Trigger is helpful for determining missing cycles or transitions and for ignoring unwanted signal reflections Interval Trigger on Coupling Between Pos Neg edges DC AC LFREJ HF...

Страница 60: ...r is generated on the second edge if it occurs within the selected interval The timing for the interval is initialized and restarted whenever the selected edge occurs Intervals of between 10 ns and 20 s can be selected Figure 8 10 Interval Trigger Trigger if the interval is smaller than the selected interval Interval width Generated Trigger Interval width T Selected interval Trigger Source Positiv...

Страница 61: ...n the second edge if it occurs after the selected interval The timing for the interval is initialized and restarted whenever the selected edge occurs Intervals of between 10 ns and 20 s can be selected Figure 8 11 Interval Trigger Trigger if the interval is greater than the selected width Interval width Generated Trigger Interval width T Selected interval Trigger Source Positive Slope Trigger can ...

Страница 62: ...e if it occurs within the selected interval range The timing for the interval is initialized and restarted whenever the selected edge occurs Intervals of between 10 ns and 20 s can be selected Figure 8 12 Interval Trigger Trigger if the interval is between the selected ranges Interval width Generated Trigger Interval width T2 Selected ranges Trigger can occur T1 T2 T1 Trigger Source Positive Slope...

Страница 63: ...after the selected interval range The timing for the interval is initialized and restarted whenever the selected edge occurs Intervals of between 10 ns and 20 s can be selected Figure 8 13 Interval Trigger Trigger if the interval is outside the selected ranges Interval width Generated Trigger Interval width T2 Selected ranges Trigger can occur T1 T2 T1 Trigger Source Positive Slope ...

Страница 64: ...shold low when less than this threshold Fig 8 15 For example the pattern could be defined as present when the trigger state for CH 1 is high CH 2 is low and EXT is irrelevant X or don t care If any of these conditions are not met the pattern state is considered absent Limits can be selected from 10 ns to 20 s Figure 8 14 Pattern Trigger Menu see page 8 33 NOT AVAILABLE ON 9304C 9310C 9314C SERIES ...

Страница 65: ... for the testing of complex logic inputs or data transmission buses Figure 8 15 Pattern Trigger Trigger when pattern conditions met CH 1 Generated Trigger Pattern Entering Pattern 1H 2L Threshold CH 2 Generated Trigger Pattern Exiting Threshold High High Low Low ...

Страница 66: ...igger connect the signal to two inputs Channels 1 and 2 or any other pair that can be triggered on For example the threshold of CH 1 could be set to 100 mV and that of CH 2 at 200 mV The Bi level Trigger will occur if the oscilloscope triggers on CH 1 for any pulse greater than 100 mV or on CH 2 for any pulse less than 200 mV For improved precision the gains of the two channels should be at the sa...

Страница 67: ...t signal A Qualified Trigger can occur immediately after the validation or within a set time after it Or it can occur following a predetermined time delay or number of potential trigger events The time delay or trigger count is restarted with every validation Figure 8 16 State and Edge Qualified Trigger Menus see pages 8 35 and 8 36 Qualified By Trigger on After 1 2 3 4 Ext Ext10 Pattern 1 2 3 4 E...

Страница 68: ...r when another signal the trigger source meets its trigger condition while the pattern is present The trigger source itself is not allowed in the pattern Applications Typical applications can be found wherever time violations occur such as in micro processor debugging or telecommunications State Qualified with Wait State Qualified Trigger with Wait Fig 8 17 is determined by the parameters of Time ...

Страница 69: ... generated on a rising edge whenever the pattern is asserted pattern present and the wait timeout has expired The timeout is respectively activated or disabled once the pattern is asserted or absent Generated Trigger Selected wait Trigger Source Positive Slope Trigger can occur Qualifier Pattern Present ...

Страница 70: ...ns Ø Events selects a minimum number of events of the trigger source An event is generated when a trigger source meets its trigger conditions On the selected event of the trigger source and before the end of the pattern a trigger can occur The count is initialized and started whenever the selected pattern begins It continues while the pattern remains When the selected count is reached the trigger ...

Страница 71: ...e beginning of each line The field signal provides the starting transition and the beginnings of line pulses are counted to allow the final trigger on the chosen line Each field the number of fields the field rate interlace factor and number of lines per picture must be specified although there are standard settings for the most common types of TV signals TV Trigger can also function in a simple a...

Страница 72: ...is identical to line 1 Number of fields eight is most useful for color PAL signals four for SECAM signals Ø 525 60 2 1 NTSC systems This setting should be used for standard 60 field NTSC signals The lines can be selected in the range 1 to 1051 where line 1051 is identical to line 1 Number of fields four is most useful for US type NTSC systems Ø 50 60 In order to allow maximum flexibility no line c...

Страница 73: ...t Trigger is useful for detecting interruptions in data streams such as network hang ups and microprocessor crashes A typical application is on the last normal interval of a signal that has disappeared completely This is essentially a single shot application usually with a pre trigger delay RIS acquisition is not useful here because the timing of the trigger timeout is insufficiently correlated wi...

Страница 74: ...8 28 Triggers and When to Use Them Figure 8 21 Dropout Trigger A trigger occurs when the timeout has expired Generated Trigger Wait timeout Trigger Source Trigger can occur ...

Страница 75: ...tterns NOT AVAILABLE ON 9304C 9310C 9314C SERIES Ø State or edge qualified events Ø TV signals Ø Dropouts Edge SMART To select SMART SETUP SMART TRIGGER This is primary menu that accesses the SMART TRIGGER menu group for choosing the type of SMART Trigger required from the type secondary menu This and the other SMART menus are described starting page 8 30 ...

Страница 76: ...while the test can be turned on or off by pressing the menu button and used in combination with the width test Width values in the range 2 5 ns to 20 s can be entered width On instructs the instrument to trigger if the pulse is greater than the value defined in that field The value can be adjusted using the associated menu knob and the test turned on or off with the menu button in combination with...

Страница 77: ...for pattern For selecting pattern Present or Absent width To trigger if the pattern is present or absent for less than the time value defined in that field The value can be adjusted with the associated menu knob and the test commuted to by pressing the corresponding menu button width To trigger if the pattern is present or absent for more than the time value defined in that field The value can be ...

Страница 78: ...turned on or off with the corresponding menu button and can be used in combination with the interval test Interval values in the range 10 ns to 20 s may be entered OR interval To trigger if the interval is greater than the value defined here which can be adjusted using the associated menu knob The test can be turned on or off using the corresponding menu button and can be used in combination with ...

Страница 79: ... available for Pattern Trigger level For modifying these values using the associated knob adjusts the level and the corresponding menu button which chooses L low H high or X Don t care holdoff To disable the trigger circuit for a definable period of time or number of events after a trigger event a change in the input signal that satisfies the trigger conditions When not turned off holdoff can be d...

Страница 80: ...elds up to eight TV type For selecting either Standard or Custom TV decoding as When Standard is chosen for selecting either 625 50 2 1 PAL SECAM or 525 60 2 1 NTSC standards When Custom is selected for specifying the number of lines and cycles and setting the interlacing factor for non standard TV signals trigger on For selecting the line and field number on which to trigger ...

Страница 81: ...t whether the qualifier signal will be valid either Above or Below that threshold When Pattern is selected as the qualifier source this menu is used to determine whether the pattern should be present or absent wait within To specify the time limit T for accepting the trigger event And alternatively to specify how much time T or how many trigger events Evs should be allowed before the acquisition i...

Страница 82: ...old and determine whether the qualifier signal is valid once it has gone above or below that threshold Pattern selected as the qualifier source determines whether the pattern should be present or absent wait within To specify the time limit T for accepting the trigger event Or to specify the delay in time T or number of trigger events Evs after a valid transition has occurred A trigger can only be...

Страница 83: ...eout if NO edge occurs on For selecting the trigger source four channel menu shown with slope To define whether the measurement starts on a Positive or Negative slope of the trigger signal Within of previous edge For defining the time out value in the range 25 ns 20 s ...

Страница 84: ...three original traces Thus Trace A for example could be set up to zoom Trace B C or D but not itself The Displayed Trace label at left of screen indicates the source The TRACE ON OFF buttons display the corresponding trace A B C or D When a trace is switched on the POSITION and ZOOM knobs and the RESET button will then be attributed to this the active trace The SELECT ABCD button assigns the contr...

Страница 85: ...e trace The ZOOM knob horizontally expands or contracts the active trace If the source of the zoomed trace is also displayed it will show an intensified region corresponding to the area of expansion While the vertically expands or contracts the active trace The RESET button resets the vertical and horizontal POSITION and ZOOM Finally the menu entry button accesses the zoom math and sequence segmen...

Страница 86: ...ints acquired zooming can be done until there are only a few points on the screen Using Multi Zoom With Multi Zoom the zoomed region of the waveform can be moved simultaneously along two or more different traces or two or more regions of the same trace When Multi Zoom On is selected from the ZOOM MATH menu see page 10 8 the horizontal zoom and position controls apply simultaneously to all displaye...

Страница 87: ...10 2 Zoom Mathematics and Math Setup mathematical function simply cancel any expansion or position change by pressing RESET ...

Страница 88: ...atistical analysis menus page 10 17 Continuous Averaging This is the repeated addition with unequal weight of successive source waveforms It is particularly useful for reducing noise on signals that drift very slowly in time or amplitude However the statistics of a continuous average tend to be worse than those from a summed average see next page on the same number of sweeps This is because the mo...

Страница 89: ... SWEEPS button or changing an acquisition parameter such as input gain offset coupling trigger condition timebase or bandwidth limit The number of current averaged waveforms of the function or its expansion is shown in the Displayed Trace label When summed averaging is selected the display is updated at a reduced rate about once every 1 5 s in order to increase the averaging speed points and event...

Страница 90: ...ther pushing the CLEAR SWEEPS button or by changing an acquisition parameter such as input gain offset coupling trigger condition or the timebase or bandwidth limit The number of currently accumulated waveforms is displayed in the function s Displayed Trace Label of that of its zoom expansion Whenever the maximum number of sweeps is reached an even larger number can be accumulated simply by changi...

Страница 91: ...any data points are involved This delay can be cut by limiting the number of data points used in the computation To do this the instrument will process the entire waveform by taking every Nth point where N depends on the timebase and the desired maximum number of points and the first point taken is always the data value at the left hand edge of the screen Combining Channels Zoom and math functions...

Страница 92: ......

Страница 93: ...sses the SETUP menus described in the remainder of this chapter using A as an example Multi Zoom For switching Multi Zoom On or Off When On all displayed traces A B C D are simultaneously controlled by the horizontal POSITION and ZOOM knobs When OFF only the active trace chosen using the SELECT ABCD button is controlled by POSITION and ZOOM Selected NOT SHOWN When a trace with a zoom of a sequence...

Страница 94: ...10 9 Zoom and Math Setup Menus Zoom use Math For toggling between No Zoom only and Yes Math functions SETUP Trace A B C or D is ZOOM of To select the source trace to be zoomed four channel menu shown ...

Страница 95: ...this page shows a setup of trace A as the sum of Channels 1 and 2 use Math To choose a math function Math Type To select Arithmetic Sum Difference Product Ratio For selecting the operator 1 2 3 4 B C D M1 M2 M3 M4 To select one of two operand source traces four channel menu shown plus 1 2 3 4 B C D M1 M2 M3 M4 To select the other operand source trace four channel menu shown ...

Страница 96: ...t available on the standard scope Avg Type To select Summed or Continuous Average for weight When Summed is selected this menu for is used to define the number of sweeps When Continuous Average is chosen the same menu becomes weight and is used to define the weight similar to number of sweeps In for the first n sweeps will be taken into account whereas in weight the last sweep will be given a weig...

Страница 97: ...y and the sampling speed affect bandwidth If high bandwidth is needed at slow timebases averaging and repetitive sampling should be considered use Math To choose a math function Math Type To select Enhanced Resolution enhance by For selecting the filter that will enhance resolution of the displayed signal from one to three bits in 0 5 bit steps 1 2 3 4 B C D M1 M2 M3 M4 To select the source trace ...

Страница 98: ...o select Extrema limits To select either Envelope Floor or Roof Floor shows only the lower and Roof only the upper part of the envelope Changing the limits does not force the analysis to start again for For selecting the number of sweeps of To select the source trace four channel menu shown Only with WP01 Math package See Signal Analysis in Appendix A for specifications ...

Страница 99: ...mag with window Using the corresponding menu button to select the FFT window type from Rectangular Hanning Hamming Blackman Harris and Flat top And the associated knob to select AC or DC of For selecting the source trace four channel menu shown Only with WP02 Spectral Analysis package See Signal Analysis in Appendix A for specifications Note During Fast Fourier Transform computation the FFT sign i...

Страница 100: ...of this chapter and Appendix C for when and how to use FFT use Math To choose a math function Math Type To select FFT AVG FFT result To select the output format of the FFT Average Magnitude Power Density Power Spectrum for For selecting the number of sweeps of To select the FFT source Only with WP02 Spectral Analysis package See Signal Analysis in Appendix A for specifications Note FFT Average can...

Страница 101: ...ting the signal offset used to compensate for any DC offset in the signal plus For selecting the source trace four channel menu shown Functions shown include functions available only with WP01 Math package See Signal Analysis in Appendix A for specifications Notes for Math Functions Ø Square root is computed on the absolute value of the source waveform Ø For logarithmic and exponential functions t...

Страница 102: ...secondary menu offering more histogram settings FIND CENTER AND WIDTH To calculate optimal center and bin width values for the histogram Histogram To select up to five source parameters for histogramming using up to For limiting the total histogram population Only with WP03 Parameter Analysis or DDM PRML Disk Drive Measurements Supplementary Disk Drive Measurements packages See these options respe...

Страница 103: ...ts can have values ranging between 1015 and 1015 use Math To choose a math function Math Type For selecting Rescale a 1 b To select a or b a or b The corresponding menu button for this menu highlights the mantissa the exponent or the number of digits while the associated knob changes the highlighted value 1 2 3 4 B C D M1 M2 M3 M4 To select the source trace four channel menu shown ...

Страница 104: ...f Correctly setting up an FFT starts with the frequency resolution or f This parameter is the spacing of samples in the frequency domain display The f is set by inputting the time duration of the time domain signal to the FFT If an acquisition channel Channel 1 or 2 or 3 or 4 is the source then the waveform duration is the capture time the TIME DIV setting multiplied by ten The relationship betwee...

Страница 105: ...using the for Math use max points menu see page 10 8 is identical to the number of samples in the acquired waveform TIMEBASE menus Chapter 7 then the span will be half the sampling frequency But if this max points for math number is less than the number of points the waveform and in turn the FFT span will be decimated The relationship between the span of the FFT and the sampling rate 1 T is illust...

Страница 106: ...he FFT transform size to account for the user entered max points for math and the display scaling In some combinations of these factors it also adjusts the length of the displayed trace The user can determine the span from the Displayed Trace Label for the math trace containing the FFT This will show the horizontal calibration in MHz div The span is also explicitly shown as the Nyquist frequency i...

Страница 107: ...n the effective sampling rate must be 20 MS s On say an oscilloscope with a sampling rate of 500 MS s the 50 000 sample default memory length and a 10 µs TIME DIV setting would be used to first give a 250 MHz span Now to obtain a 10 MHz span the sampling rate must be reduced This can be done in either of two ways a In TIMEBASE decreasing the number of samples by setting the RECORD UP TO menu to 25...

Страница 108: ...would result in a full scale range of 12 5 MHz or 1 25 MHz Div To maintain a display scale factor of 1 2 or 5 it decimates the acquired waveform by 25 000 1 and calculates the FFT using a 2000 point transform This results in a scale factor of 2 MHz Div The display is truncated at 6 25 divisions to retain the original 12 5 MHz span ...

Страница 109: ...atible traces are selected If incompatible traces are selected a warning message is displayed at the top of the screen And if compatible traces are not matched in time their XY diagram will be displayed showing the shifting in time or in frequency between them The T or f indicator is displayed in the Displayed Trace Label at left of screen Persistence In Persistence Mode the oscilloscope can displ...

Страница 110: ...n separate grids When Parameters are used the parameter style grid comes into play automatically Other grid styles illustrated on the following pages offer the choice of a variety of ways to view one or more traces in either Standard or XY Mode Standard and XY Display Grids Single ...

Страница 111: ...11 3 Dual Quad ...

Страница 112: ...11 4 Display Parameter s XY only ...

Страница 113: ...11 5 XY Single XY Dual ...

Страница 114: ...ly the sample points are displayed Grids For selecting the number of grids W form Text intensity Adjusts the screen intensity for the waveform and associated text using the attributed menu knob Grid intensity Adjusts the screen intensity of the grid using the attributed menu knob Note If W form Text intensity is turned down to 0 the waveform and text disappear Press the DISPLAY button to return au...

Страница 115: ...ple points with a line segment or OFF when only the sample points are displayed Persistence Setup To access the PERSISTENCE Setup menus see next page Grids For selecting the number of grids W form Text intensity Adjusts the screen intensity for the waveform and associated text using the attributed menu knob Grid intensity Adjusts the screen intensity of the grid using the attributed menu knob Note...

Страница 116: ... Setup is selected from DISPLAY SETUP Persistence To select whether persistence is applied to all or to the top two traces Persist for For selecting the persistence duration in seconds The number of sweeps accumulated up to 1 million is displayed below the grid ...

Страница 117: ...t Join To select Dot Join ON connecting the sample points with a line segment or OFF when only the sample points are displayed Grids For selecting the grid style W form Text intensity Adjusts the screen intensity for the waveform and associated text using the attributed menu knob Grid intensity Adjusts the screen intensity of the grid using the attributed menu knob ...

Страница 118: ... the CAL BNC connector magnitude frequency shape trigger out pass fail use Hardcopy Setup see page 12 2 To access secondary menu for viewing changing printer settings Time Date Setup page 12 4 To access secondary menu for adjusting the real time clock displayed in the upper left hand corner of the screen GPIB RS232 Setup page 12 5 To access secondary menu for viewing changing interface settings Ma...

Страница 119: ...inter is connected a storage unit such as Floppy or portable hard disk HDD or the internal printer If a port the GPIB RS232 menu should be checked to ensure settings are correct File names are assigned automatically when copying to storage units page feed For starting when On is selected a new page each time SCREEN DUMP is pressed Press to make a copy of the screen display printer To select the ty...

Страница 120: ...onnected a storage unit such as Floppy or portable hard disk HDD or the internal printer If a port the GPIB RS232 menu should be checked to ensure settings are correct File names are assigned automatically when copying to storage units auto print For generating On a hard copy of the screen and send to the internal printer after every acquisition cm division For selecting the expansion factor Note ...

Страница 121: ...rd time LOAD CHANGES NOW To activate the changes made with the Hour Min Sec and Day Mnth Year buttons and knobs see below Hour Min Sec Using the corresponding menu button for toggling between Hour Min utes and Sec onds and the associated menu knob to adjust the value Day Mnth Year Using the corresponding menu button for toggling between Day Mnth and Year and the associated menu knob to adjust the ...

Страница 122: ...nal computer RS 232 C Connector Pin Assignments DB9 Pin No Line Name Description 3 T D Transmitted Data from the oscilloscope 2 R D Received Data to the oscilloscope 7 RTS Request To Send from the oscilloscope If the software Xon Xoff handshake is selected it is always TRUE Otherwise hardware handshake it is TRUE when the oscilloscope is able to receive characters and FALSE when the oscilloscope i...

Страница 123: ...communication When RS 232 is selected the GPIB interface is in Talk Only mode Any change becomes effective immediately Parity To select the odd or even parity or none for RS 232 communication Stop bits For selecting the number of stop bits for RS 232 communication Baud Rate To set the Baud Rate for RS 232 communication using the attributed menu knob GPIB Device Address To choose the appropriate GP...

Страница 124: ...D Format The removable hard disk structure is based on the PCMCIA III JEIDA 4 0 standard The media is arranged as a DOS partition containing files as in any DOS floppy or hard disk The HDD format uses 512 bytes per sector and four sectors per cluster One cluster is the minimum file size any files smaller than 2048 bytes in size will still use one cluster s allocation of 2048 bytes of disk space Su...

Страница 125: ...dium the old file will be deleted Type Default Name Customized Name Manually stored waveform files Stt nnn xxxxxxxx nnn Automatically stored waveform files Att nnn xxxxxxxx nnn Panel files Pnnn PNL xxxxxnnn PNL Hard copy files Dnnn TIF Dnnn BMP Dnnn PRT xxxxxnnn TIF xxxxxnnn BMP xxxxxnnn PRT Template files LECROYvv TPL Cannot be changed Directory name LECROY_1 DIR xxxxxxxx Spreadsheet Sttnnn TXT x...

Страница 126: ...tored waveform files will be renamed the oldest group of files will be named Axx 001 the second oldest Axx 002 and so on The current sequence number is deduced from inspection of all file names in the working directory regardless of file type panel hard copy or waveform The highest occupied numeric file name extension of the form nnn is determined and the next highest number is used as the current...

Страница 127: ...12 10 UTILITIES Protected will be displayed on the upper part of the grid whenever the medium is accessed for writing ...

Страница 128: ...tilities OPTION To delete files format or copy a machine template onto memory card The Utilities menus accessed by selection of this menu for the optional Memory Card are similar to those accessed for Floppy Disk shown on the following pages Floppy Disk Utilities To delete files format or copy a machine template onto floppy disk The examples on the following pages illustrate this selection Hard Di...

Страница 129: ... UTIL These menus appear when Floppy Disk UTILITIES is selected from MASS STORAGE and Ø a floppy has been newly inserted or Ø there is no floppy in the drive RE READ DRIVE To read the floppy and display directory contents ...

Страница 130: ...of the selected file on the media TEMPLATE AND FORMATTING To access a secondary menu for formatting storage media or copying to it the machine template The template is an ASCII text file containing all information required for decoding the descriptor part of a binary waveform DO DELETE To delete the file selected in the File menu below File For selecting the file to be deleted with the attributed ...

Страница 131: ...ormat with an interleave factor of two which optimizes throughput to and from the scope Density This menu appears only in FORMAT FLOPPY For selecting density 1 44 MB HD or 720 kB DD COPY TEMPLATE TO For copying the machine template an ASCII text file containing all the information required to decode the descriptor part of a binary waveform to the medium ...

Страница 132: ...AT To quickly 15 seconds clear the portable hard disk drive FULL FORMAT For a complete formatting of the HDD recommended if the disk is non readable COPY TEMPLATE TO For copying the machine template an ASCII text file containing all the information required to decode the descriptor part of a binary waveform to the medium ...

Страница 133: ...ng the Add New Directory menu on drive For selecting the medium File Name Preferences To access the secondary menu for defining custom names for waveform setup or hardcopy files see next page DELETE THIS DIRECTORY To delete the directory selected in work with menu see below work with For selecting the directory to be used for file storage and retrieval Add new Directory To access secondary menu fo...

Страница 134: ...cation RESTORE DEFAULT NAME For restoring the file type selected in the File Type menu see below to its default name ENTER NEW FILE NAME To validate the newly defined name BACKSPACE For moving back one space and erasing the previous character INSERT To move forward to create a space for insertion of a character character For selecting a character using the menu knob File Type To select the file ty...

Страница 135: ...Card For selecting the character to be modified MAKE THIS DIRECTORY For validating the new directory BACKSPACE To move back one space and erase the previous character INSERT For moving forward to create a space for the insertion of a character character For selecting a character using the menu knob ...

Страница 136: ...AGE File Transfers is selected and copies files from one medium to another Direction DEPENDING ON OPTIONS INSTALLED To select source copy from and destination copy to Which files For selecting the type of file for copying DO COPY To execute the copying ...

Страница 137: ... menus On GAIN Changes all OFFSETS fixed Ø In For specifying the offset behavior of a gain VOLTS DIV change The offset can be fixed either in Volts or vertical Divisions Ø Automatic Recalibration For turning the automatic recalibration ON or OFF Default is ON Turning this off may speed up the acquisition but during that time calibration is not guaranteed Cursors Measure Accesses the secondary menu...

Страница 138: ...12 21 Ø FLASH UPDATE Offering the Update from and Update Program menus illustrated next page ...

Страница 139: ...12 22 UTILITIES The full screen warning message shown when FLASH UPDATE has been selected ...

Страница 140: ...e is ready to accept a trigger event Trigger Rdy When the instrument is switched on the calibration signal is automatically set to its default state 1 kHz 1 V square wave mode To change the kind of signal SET TO To quickly reset the CAL BNC output to its default state Shape To change the form of the calibration signal Amplitude Using the associated knob for setting the desired high level for all C...

Страница 141: ... page the scope will store the waveform in an ASCII format But this will create an output file requiring 10 20 times the disk space of the original LeCroy binary file A one megabyte record will typically take up 13 15 MB stored in ASCII Furthermore waveforms stored in ASCII cannot then be recalled back into the scope Note Ø The capacity of the Reference and Zoom Math memories each match those of t...

Страница 142: ...13 2 WAVEFORM STORE RECALL ...

Страница 143: ...uto Store For automatically storing waveforms after each acquisition Fill stores until the medium is filled while Wrap stores continuously discarding first in first out the oldest files DO STORE To store in accordance with specifications made in the store and to menus see below store For selecting the waveform All displayed can only be selected when storing to optional storage media to To select t...

Страница 144: ...13 4 WAVEFORM STORE RECALL ASCII SETUP Data Format This secondary menu accessed through SETUP ASCII FORMAT offers a choice of ASCII formats For details on each format see Appendix E ...

Страница 145: ...To execute recall based on the selections made in the from Memory and to menus see below At the same time resets the horizontal and vertical positions as well as the zooms showing the full contents of the memory at its original magnification from Memory For selecting the source memory to To select the destination trace Note Performing a recall operation from an internal memory to Trace A D overrid...

Страница 146: ... selections made in the File and to menus see below File To select the file on which the waveform is stored using the attributed menu knob Note The files listed will be those in the current working directory to For selecting the destination memory If the All M is selected up to four files with the same three digit numeric extension as the current File selection will be recalled into memories M1 4 ...

Страница 147: ...or time and amplitude using Time cursors can be displayed at the cursor location Measured amplitudes are relative to ground measured times to the trigger point In Relative Mode a pair of Amplitude or Time cursors is controlled providing readings on the difference between the two in amplitude or time and amplitude respectively Amplitudes are shown in the Trace Label for each trace When Time cursors...

Страница 148: ... value X value Product 4 f arc tan Y X range 180 to 180 Angle polar 5 r sqrt X X Y Y Radius distance to origin The definition of X and Y depends on the cursor used The table below shows how X and Y are defined for each type of measurement Cursors TAbs AAbs ARel Org 0 0 Org VXOffset VYOffset TRel DX VXRef 0 VXDif VXRef VXRef 0 VXRef VXOffset VXDif VXRef DY VYRef 0 VYDif VYRef VYRef 0 VYRef VYOffset...

Страница 149: ...iff Ref which displays the amplitude values for each cursor Not available in persistence mode Reference cursor To control the Reference cursor available with Relative cursors using the associated menu knob With Track ON both Reference and Difference cursors are controlled by this knob and move together a constant time or voltage interval maintained between them This tracking interval is represente...

Страница 150: ...e parameter values are accumulated and can be displayed for all modes In addition to the overall number of sweeps used each parameter has its average lowest and highest value The standard deviation of the parameter is also calculated Parameter Symbols The algorithms that determine pulse waveform parameters are able to detect those situations where the mathematical formulas may be applied However t...

Страница 151: ...ulated on a histogram Insufficient data to determine the parameter Warnings Amplitude histogram is flat within statistical fluctuations minimum and maximum are used to assign top and base Only an upper limit could be estimated the actual value of the parameter may be smaller than the displayed value The signal is partially in overflow The signal is partially in underflow The signal is partially in...

Страница 152: ...tion conditions change or when the CLEAR SWEEPS button is pressed As long as Parameters is highlighted in the top menu the accumulation of statistics continues even if the statistics are not shown on trace To select the trace for which the voltage parameters are measured The choices available in this menu will depend on the traces displayed a maximum of four traces can be displayed Here Traces 1 a...

Страница 153: ...on is pressed As long as Parameters is highlighted in the top menu the accumulation of statistics continues even if the statistics are not shown on trace For selecting the trace for which the time parameters are to be measured The choices available in this menu will depend on the traces displayed a maximum of four traces can be displayed Here Traces 1 and 2 are displayed and 2 selected from To det...

Страница 154: ...ime the acquisition conditions change or when the CLEAR SWEEPS button is pressed As long as Parameters is highlighted in the top menu the accumulation of statistics continues even if the statistics are not shown CHANGE PARAMETERS For accessing the secondary CHANGE PARAM menu see following pages from To determine the starting point in screen divisions for parameter measurements Track On links contr...

Страница 155: ... see below will feature all parameters However when a particular category is selected only those parameters in the category are shown DELETE ALL PARAMETERS For deleting all parameters previously selected measure To choose the new parameter to be measured on this line When is selected the line is not used of For selecting the channel or trace on which the parameter will be measured four channel men...

Страница 156: ...five different parameters 1 2 3 4 or 5 Category To specify the category or type of parameter MORE t lv SETUP Calls up the t lv customization menu next page measure Set at t lv source Using the menu button selects the channel 1 2 3 or 4 or memory A B C or D While the knob selects from which and to which channel the measurement is to be made ...

Страница 157: ...crossing is recognized when an acquisition point in the waveform passes through the threshold level by 1 2 the hysteresis division setting from For selecting the voltage setting the level on the trace at which the timing should start And to select where the timing should start Pos for rising edge Neg for falling edge First for either positive or negative edges to For selecting the voltage setting ...

Страница 158: ...veform peak trough pair must exceed in order not be considered either noise or a bump This threshold crossing is recognized when an acquisition point in the waveform passes through the threshold level by 1 2 the hysteresis division setting clock edge To select the clock edge or edges used for this parameter measurement data edge For selecting the data edge or edges used for the measurement ...

Страница 159: ...ted against limits at the same time And in tolerance mask testing a trace can be compared to a tolerance mask Whether the tests pass or fail any or all of the following actions can be provoked Ø Stop capturing further signals Ø Dump the screen image to a hardcopy unit Ø Store selected traces to internal memory to a memory card optional or to a floppy Ø Sound the buzzer Ø Emit a pulse on the CAL BN...

Страница 160: ...r Fail testing For turning testing Off or On Testing is turned off in order to observe only the parameter variations CHANGE TEST CONDITIONS To access the secondary CHANGE TEST menu see next page from To determine the starting point in screen divisions for parameter measurements to To determine the end point in screen divisions ...

Страница 161: ...or if no test is required No Test choose To select Param DELETE ALL TESTS For deleting all tests previously selected measure For selecting the new parameter to be measured on this line When is selected the line is not used of For selecting the channel or trace on which the parameter will be measured four channel menu shown ...

Страница 162: ... Param 14 15 DELETE ALL TESTS For deleting all tests previously selected True if For selecting the adequate relation smaller than or greater than limit To make the choice of one of three modifications of a limit its mantissa exponent and the number of digits for the representation of its mantissa The corresponding menu button is used to select and the associated knob to modify the number in that f...

Страница 163: ... condition of To select channel or trace for testing four channel menu shown are For choosing this mask test condition mask To select mask trace A B C or D Note Pass Fail testing against a mask is affected by horizontal and vertical zooming of the mask trace The test will be made inside the area bordered by the parameter cursors Timebases of the mask and the trace under test should be identical Fo...

Страница 164: ... W FORM see previous chapter memories M1 M4 can be recalled to traces A to D for display INVERT MASK To generate an inverted mask Use W form For selecting the waveform to be used as reference The mask will be generated around this waveform four channel menu shown MAKE MASK To generate the mask delta V For selecting tolerance in amplitude using the attributed knob delta T For selecting tolerance in...

Страница 165: ...ICE from To select the device into For selecting D M4 to automatically display the mask on screen or M1 M2 M3 or M4 INVERT MASK For generating an inverted mask DO RECALL To recall the mask File To select the appropriate mask using the associated menu knob ...

Страница 166: ...CTIONS To delete all previously selected actions If To determine if the action will be taken on PASS or FAIL Then For selecting the action Dump in this example The selected action will then be activated in the menu below Dump To perform Yes or disable No the action chosen in the Then menu see above The choice will then be indicated alongside the already selected action in Then ...

Страница 167: ...portable hard disk HDD depending on options installed Recall Save To choose to save a panel setup or recall one already saved When Save is selected as shown here the TO SETUP menus appear While when Recall is chosen the FROM SETUP menus shown overleaf appear TO SETUP 1 2 3 or 4 For saving any of four possible setups to Card Flpy or HDD For saving a setup to floppy memory card or hard disk dependin...

Страница 168: ...M SETUP 1 2 3 or 4 For recalling any of four possible saved setups In the example shown here all four possible setups have been stored When no setup has been stored that menu will indicate Empty FROM DEFAULT SETUP To choose a default setup already stored in the scope from Card Flpy or HDD For accessing the secondary RECALL SETUPS menu to recall a setup stored on floppy card or portable hard disk d...

Страница 169: ...py or card or portable hard disk depending on the options installed and the medium on which the desired setup is stored DO RECALL To perform the recall of the setup selected in the File menu see below File For selecting the stored setup using the attributed menu knob ...

Страница 170: ...to summon the STATUS menu and access full screen summaries of the oscilloscope s system and other functional status Acquisition Status Vertical sensitivity probe attenuation offset and coupling for each channel as well as timebase and trigger status summaries ...

Страница 171: ...mware version and software and hardware options installed The MORE VERSION INFORMATION menu is used to perform a cyclic redundancy check CRC of the internal firmware and will generate a checksum that can be used to ensure the firmware is uncorrupted ...

Страница 172: ...timing information four channel menu shown in this example And when Text Times is selected the for and Select menus shown here also appear allowing a trace or memory to be selected and a segment range to be specified for information Refer to the Remote Control Manual ...

Страница 173: ...16 4 SHOW STATUS Waveform Detailed status information on channels memories zoom and math or displayed traces specified using the bottom menu which appears when Waveform is selected from the top ...

Страница 174: ...can be selected and then cleared using the CLEAR INACTIVE menu The dedicated persistence data maps for each channel are dynamically created resized and deleted as necessary The allocation of memory to each of these data maps will appear in this menu Persistence data maps are cleared using the CLEAR SWEEPS button ...

Страница 175: ... MS s simultaneously on each channel Sensitivity 2 mV div to 5 V div fully variable Scale Factors Wide range of probe attenuation factors Offset Range Ø 2 00 9 9 mV div 120 mV Ø 10 0 199 mV div 1 2 V Ø 0 2 5 0 V div 24 V DC Accuracy 2 full scale eight divisions at 0 V offset Vertical Resolution 8 bits Bandwidth Limiter 30 MHz Model 9304C 9304CM 9310C 9310CM 9310CL 9314C 9314CM 9314CL Number of Cha...

Страница 176: ...10C 9314C 2 200 9304CM 9310CM 9314CM 2 500 9310CL 9314CL 2 2000 Timebase System Timebases Main and up to four Zoom Traces Time Div Range 1 ns div to 1000 s div Clock Accuracy 0 002 Interpolator resolution 10 ps Roll Mode Ranges 500 ms 1000 s div For 50 000 points 10 1000 s div External Clock 100 MHz on EXT input with ECL TTL or zero crossing levels Triggering System Modes Normal Auto Single and St...

Страница 177: ...riggers on any source only if a given state or transition number of events time interval on another source TV Selection of both line up to 1500 and field number up to 8 for PAL SECAM NTSC or nonstandard video Exclusion Trigger Triggers only on shorter than normal defined aberrations Autosetup AUTOSETUP button Sets timebase trigger and sensitivity to display wide range of repetitive signals amplitu...

Страница 178: ...e or Infinite Persistence Real time Clock Date hours minutes seconds Vertical Zoom Up to 5x Vertical Expansion 50x with averaging up to 40 µV sensitivity Horizontal Zoom Model Zoom Factor 9304C 9310C 9314C 1000x 9304CM 9310CM 9314CM 5000x 9310CL 9314CL 20 000x Signal Analysis Waveform Processing Processing Functions Add Subtract Multiply Divide Negate Identity and Summation Averaging four function...

Страница 179: ...A 5 9304C Series 9310C Series 9314C Series Extrema Roof Floor or Envelope values of from 1 to 106 waveforms with optional WP01 Advanced Waveform Math Package ...

Страница 180: ...fferences relative to each other Relative Voltage Horizontal bars measure voltage differences up to 0 2 full scale in single grid mode Absolute Time Cross hair marker measures time relative to trigger and voltage with respect to ground Absolute Voltage Reference bar measures voltage with respect to ground Interfacing Remote Control By GPIB and RS 232 C for all front panel controls internal functio...

Страница 181: ...ity 80 for temperatures up to 31 C decreasing linearly to 50 relative humidity at 40 C Altitude Up to 2000 m 6560 ft operating 40 C max Power 90 250 V AC 45 66 Hz 150 W Battery Backup Front panel settings maintained for two years Dimensions HWD 8 5 x 14 5 x 16 25 inches 264 x 397 x 453 mm Weight 12 5 kg 27 5 lb net 18 kg 40 lb shipping Warranty Three years Conformity EMC EN 50082 1 conformity Safe...

Страница 182: ......

Страница 183: ...Hz typical at tip of optional FET probe AP020 Number of Channels Ø 9344C 9354C Series four Ø 9350C Series two Number of Digitizers Ø 9344C 9354C Series four 9350C Series two 9344C Series MEMORY PER CHANNEL IN POINTS PER MODEL CHANNELS USED PEAK DETECT ON OFF MAX SAMPLE RATE C CM CL ACTIVE CHANNELS All Peak Detect Off 250 MS s 50k 250k 2M All 100 MS s data 25k data 100k data 1M data All Peak Detect...

Страница 184: ...lsCombined by PP092 Adapter Peak Detect OFF 2 GS s 250k 1M 8M CH 2 PP092 input 9354CTM All Peak Detect OFF 500 MS s 500 000 All Two Channels Paired Peak Detect OFF 1 GS s 1M CH 2 and CH 3 100 MS s data 250k data All All Peak DetectON 400 MS s peak 250k peak 2 5 ns peak detect FourChannelsCombined by PP092 Adapter Peak Detect OFF 2 GS s 2M CH 2 PP092 input Sensitivity 2 mV div to 5 V div fully vari...

Страница 185: ...nnels active Peak Detect Ø 9344C Series Captures and displays 5 ns glitches and other high speed events Ø 9350C 9354C Series Captures and displays 2 5 ns glitches and other high speed events Sequence Stores multiple events in segmented acquisition memories Deadtime Between Segments 80 µs Number of Segments Available Model Segments 9344C 9350C 9354C 2 200 9344CM 9350CM 9354CM 9354CTM 2 500 9344CL 9...

Страница 186: ...r Types Signal or Pattern Width Triggers on width between two limits of between 2 5 ns and 20 s Signal or Pattern Interval Triggers on interval between two limits of between 10 ns and 20 s Dropout Triggers if the input signal drops out for a time out longer than 25 ns 20 s State Edge Qualified Triggers on any source only if a given state or transition number of events time interval on another sour...

Страница 187: ...A 13 9344C Series 9350C Series 9354C Series where each source can be defined as High Low or Don t Know and the trigger as the pattern s beginning or end ...

Страница 188: ... selected rise and fall time 1 ns typical calibrator also offers trigger or Pass Fail output Signal Viewing Display CRT 12 5 x 17 5 cm 9 diagonal raster Resolution 810 x 696 points Grids 1 2 or 4 grids Formats YT XY and both together Graticules Internally generated separate intensity control for grids and waveforms Waveform Style Vectors which can be switched on and off connect individual sample p...

Страница 189: ...A 15 9344C Series 9350C Series 9354C Series 9354CTM 50 000x 9344CL 9350CL 9354CL 100 000x ...

Страница 190: ...Spectral Analysis with five windowing functions and FFT averaging with optional WP02 Spectrum Analysis Package Histogramming and Trending With optional WP03 Parameter Analysis Package in depth diagnostics on waveform parameters Internal Memory Waveform Memory Up to four 16 bit Memories M1 M2 M3 M4 Processing Memory Up to four 16 bit Waveform Processing Memories A B C D Setup Memory Four non volati...

Страница 191: ...Jet and EPSON printers HP 7400 and 7500 series or HPGL compatible plotters Ø Optional internal high resolution graphics printer Output Formats Binary or ASCII waveform output compatible with spreadsheets MATLAB Mathcad General Auto calibration Ensures specified DC and timing accuracy Temperature 5 to 40 C 41 to 104 F rated Humidity 80 for temperatures up to 31 C decreasing linearly to 50 relative ...

Страница 192: ...ale Factors Wide range of probe attenuation factors 9370C 9374C Series MEMORY PER CHANNEL POINTS Model CHANNELS USED PEAK DETECT ON OFF MAX SAMPLE RATE C CM CTM CL ACTIVE CHANNELS All Peak Detect OFF 500 MS s 50k 250k 500k 2M All 100 MS s data 25k data 100k data 250k data 1M data All All Peak DetectON 400 MS s peak 25k peak 100k peak 250k peak 1M peak 2 5 ns peak detect 9370C M L 9374C M L TM TwoC...

Страница 193: ...quisition Modes Random Interleaved Sampling RIS For repetitive signals from 1 ns div to 5 µs div Single shot For transient and repetitive signals from 10 ns div all channels active Peak Detect Captures and displays 2 5 ns glitches and other high speed events Sequence Stores multiple events in segmented acquisition memories Deadtime Between Segments 80 µs Number of Segments Available Model Segments...

Страница 194: ... 0 99 999 999 events Internal Trigger Range 5 div EXT Trigger Max Input Ø 50 Ω 1 5 V DC 500 mW or 5 V rms Ø 1 MΩ 15 pF 400 V max DC peak AC 10 kHz EXT Trigger Range 0 5 V 5 V with Ext 10 Trigger Timing Trigger Date and Time listed in Memory Status menu SMART Trigger Types Signal or Pattern Width Triggers on width between two limits of between 2 5 ns and 20 s Signal or Pattern Interval Triggers on ...

Страница 195: ... two seconds Vertical Find Automatically sets sensitivity and offset Probes Probe Model One PP005 probe supplied per channel 10 1 10 MΩ 11 pF 500 V max input FET probes purchased separately fully compatible with entire scope series Probe calibration Max 1 V into 1 MΩ 500 mV into 50 Ω frequency and amplitude programmable pulse or square wave able to be selected rise and fall time 1 ns typical calib...

Страница 196: ...ional WP01 Advanced Waveform Math Package Extrema Roof Floor or Envelope values of from 1 to 10 6 waveforms with WP01 Option ERES Low Pass digital filter provides up to 11 bits vertical resolution sampled data always available even when trace turned off any of above modes usable without destroying data with WP01 Option FFT Spectral Analysis with five windowing functions and FFT averaging with opti...

Страница 197: ...III Ports Optional for memory cards flash cards and removable hard disks Floppy Disk High density 3 5 inch floppy disk drive DOS format Hardcopy TIFF and BMP formats available for import to Desktop Publishing programs printers and plotters HP DeskJet HP ThinkJet QuietJet LaserJet PaintJet and EPSON printers HP 7400 and 7500 series or HPGL compatible plotters Ø Optional internal high resolution gra...

Страница 198: ...fications Safety Designed to comply with EN 61010 1 UL and cUL listed File E 170588 Protection Category I Installation Over Voltage Category II Pollution Degree 2 See Declaration of Conformity for further details ...

Страница 199: ...ide range of probe attenuation factors Offset Range Ø 2 00 4 99 mV div 400 mV Ø 5 99 mV div 1 V Ø 0 1 1 V div 10 V Ø 1 10 V div 100 V 1 MΩ Only Ø 20 V over the full sensitivity range using AP 020 FET probe 9384C Series MEMORY PER CHANNEL IN POINTS Model CHANNELS USED PEAK DETECT ON OFF MAX SAMPLE RATE C CM CTM CL ACTIVE CHANNELS All Peak Detect OFF 1 GS s 100k 500k 2M All 100 MS s data 50k data 25...

Страница 200: ...A 26 Specifications FourChannelsCombined by PP094 Adapter Peak Detect OFF 4 GS s 400k 2M 8M One PP094 input ...

Страница 201: ...gh speed events Sequence Stores multiple events time stamped in segmented acquisition memories Deadtime Between Segments 80 µs Number of Segments Available Model Segments 9384C 2 500 9384CM 9384CTM 9384CL 2 2000 Timebase System Timebases Main and up to four Zoom Traces Time Div Range 1 ns div to 1000 s div Clock Accuracy 10 ppm Interpolator resolution 10 ps Roll Mode Ø Ranges 500 ms 1000 s div Ø F...

Страница 202: ...ate or transition number of events time interval on another source TV Selection of both line up to 1500 and field number up to 8 for PAL SECAM NTSC or nonstandard video Exclusion Trigger Triggers only on shorter than normal defined aberrations Pattern Triggers on the logic combination of the five inputs CH 1 CH 2 CH 3 CH 4 and EXT Trigger where each source can be defined as High Low or Don t Know ...

Страница 203: ...vidual sample points highlighted as dots Modes Normal XY Variable or Infinite Persistence Real time Clock Date hours minutes seconds Vertical Zoom Up to 5x Vertical Expansion 50x with averaging up to 80 µV sensitivity with optional WP01 Advanced Waveform Math Package Horizontal Zoom Waveforms can be expanded to give 2 2 5 points div Model Zoom Factor 9384C 2000x 9384CM 9384CTM 10 000x 9384CL 80 00...

Страница 204: ...A 30 Specifications waveforms in the basic instrument up to 106 averages possible with optional WP01 Advanced Waveform Math Package ...

Страница 205: ...e Cursor Measurements Relative Time Arrow cursors measure time and voltage differences relative to each other Relative Voltage Horizontal bars measure voltage differences up to 0 2 full scale in single grid mode Absolute Time Cross hair marker measures time relative to trigger and voltage with respect to ground Absolute Voltage Reference bar measures voltage with respect to ground Interfacing Remo...

Страница 206: ...to 104 F rated Humidity 80 for temperatures up to 31 C decreasing linearly to 50 relative humidity at 40 C Altitude Up to 2000 m 6560 ft operating 40 C max Power 90 250 V AC 45 66 Hz 350 W Battery Backup Front panel settings maintained for two years Dimensions HWD 8 5 x 14 5 x 16 25 inches 264 x 397 x 453 mm Weight 13 kg 28 6 lb net 18 5 kg 40 7 lb shipping Warranty Three years Conformity EMC EN 5...

Страница 207: ...ad of successive trace averaging Advantages Enhanced resolution filtering improves two important characteristics of the oscilloscope Resolution is improved by a fixed amount for each filter This true increase in resolution occurs whether or not the signal is noisy or whether a single shot or repetitive signal Signal to noise ratio SNR is improved in such a way as to be dependent on the form of the...

Страница 208: ...mprovement due to the removal of coherent noise signals feed through of clock signals for example is decided 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 desirable properties First the filters do not distort the relative position of different e...

Страница 209: ...ord has a single shot or slowly repetitive nature and averaging cannot be used There are two particular situations in which enhanced resolution is especially useful One is when the signal is noticeably noisy and measurements of the noise are not required The signal can be cleaned up by using the enhanced resolution function The other is when even if the signal is not particularly noisy high precis...

Страница 210: ... the spectrum of a square signal before top grid and after bottom grid enhanced resolution processing The result clearly illustrates how the filter rejects high frequency components from the signal The higher the bit enhancement the lower the resulting bandwidth ...

Страница 211: ...solution In this example the bottom trace has been significantly enhanced by a three bit enhanced resolution function Note The original signal being highly oversampled the resulting bandwidth is still high enough for the signal not to be distorted ...

Страница 212: ...illustration shows the effect of enhanced resolution on a noisy signal The original trace top grid has been processed by a two bit enhanced resolution filter The result bottom grid shows a smooth trace where most of the noise has been eliminated ...

Страница 213: ...lter the 2 bit enhancement filter is illustrated below indicating the 3 dB cut off frequency of 5 8 of the Nyquist frequency Ø The filtering must be performed on finite record lengths data will lost at the start and end of the waveform so that the trace becomes slightly shorter after filtering Ø The number of samples lost is exactly equal to the length of the impulse response of the filter used an...

Страница 214: ...bserve in the frequency domain If sampling is done at a rate fast enough to faithfully approximate the original waveform usually five times the highest frequency component in the signal the resulting discrete data series will uniquely describe the analog signal This is of particular value when dealing with transient signals because unlike FFT conventional swept spectrum analyzers cannot handle the...

Страница 215: ... explanations Histogramming in Trace C tracks the spread of the first harmonic Figure C 1 Slicing the waveform in the fashion described above is tantamount to diluting the spectral energy in an infinite number of side lobes which correspond to multiples of the frequency resolution f Fig C 2 The observation window or capture time T determines the frequency resolution of the FFT f 1 T Whereas the sa...

Страница 216: ...tance in Hz between the center frequencies of two neighboring bins is always the same f Power Density Spectrum Because of the linear scale used to show magnitudes lower amplitude components are often hidden by larger components In addition to the functions offering magnitude and phase representations the FFT option offers power density and power spectrum density functions selected from the FFT res...

Страница 217: ...nalyzed is f N 2 10 kHz 100 k 2 500 MHz FFT Pitfalls to Avoid Take care to ensure that signals are correctly acquired improper waveform positioning within the observation 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 bandpass filters centered at mu...

Страница 218: ...cy components Intermediate components exhibit a lower and broader peak The broadening of the base stretching out in many neighboring bins is termed leakage Cures for this are to ensure that an integral number of periods is contained within the display grid or that no discontinuities appear at the edges Another is to use a window function to smooth the edges of the signal Choosing a Window The choi...

Страница 219: ...ase is conditioned by the cut off frequency of the Eres low pass filter and the noise shape frequency distribution LeCroy digital oscilloscopes employ FIR digital filters so that a constant phase shift is maintained The phase information is therefore not distorted by the filtering action Spectral Power Averaging Even greater dynamic range improvement is obtained on signals showing periodicity More...

Страница 220: ... a 3 dB cutoff o1 11 MHz obtained by exciting the filter with a white noise source Fig C 3 and a sine swept generator Fig C 4 Both techniques give substantially the same results The choice of method is governed by the availability of an adequate generating source The spectra of single time domain waveforms can be computed and displayed to obtain power averages obtained over as many as 50 000 spect...

Страница 221: ...ificantly alter the spectrum Effects such as leakage and aliasing that distort the spectrum must be understood if meaningful conclusions are to be arrived at when using FFT An effective way to reduce these effects is to maximize the acquisition record length Record length directly conditions the effective sampling rate of the scope and therefore determines the frequency resolution and span at whic...

Страница 222: ...pectrum These are 1 Transform Size N number of input points 2 Nyquist frequency sample rate and 3 Frequency Increment f between two successive points of the spectrum These parameters are related as Nyquist frequency f N 2 Where f 1 T and where T is the duration of the input waveform record 10 time div The number of output points is equal to N 2 Note on Maximum Points FFT spectra are computed over ...

Страница 223: ... FFT calculation The power density is suitable for characterizing broad band noise It is displayed on a logarithmic vertical axis calibrated in dBm Power Spectrum The signal power or magnitude represented on a logarithmic vertical scale 0 dBm corresponds to the voltage 0 316 V peak which is equivalent to 1 mW into 50 Ω The power spectrum is suitable for characterizing spectra which contain isolate...

Страница 224: ...r multiple of the fundamental frequency of the window Signals other than these types will show varying amounts of spectral leakage and scallop loss corrected by selecting another type of window Hanning Von Hann Reduce leakage and improve amplitude accuracy However frequency resolution is also reduced Hamming Reduce leakage and improve amplitude accuracy However frequency resolution is also reduced...

Страница 225: ... be moved into the frequency domain by going beyond the right hand edge of a time domain waveform The Relative Time cursors can be moved into the frequency domain to simultaneously indicate the frequency difference and the amplitude difference between two points on each frequency domain trace The Absolute Voltage cursor reads the absolute value of a point in a spectrum in the appropriate units and...

Страница 226: ...end of the record these are replaced by zeros before FFT processing FFT source data over underflow The source waveform data has been clipped in amplitude either in the acquisition gain too high or inappropriate offset or in previous processing The resulting FFT contains harmonic components which would not be present in the unclipped waveform The settings defining the acquisition or processing shou...

Страница 227: ...mplementation of the DFT Discrete Fourier Transform X N x W n k nk k k N 1 0 1 where xk is a complex array whose real part is the modified source time domain waveform and whose imaginary part is 0 Xn is the resulting complex frequency domain waveform W e j N 2π and N is the number of points in xk and Xn The generalized FFT algorithm as implemented here works on N which need not be a power of 2 4 T...

Страница 228: ...is needed The appropriate part of the complex result is given as the result R n or I n or R n jI n as defined above If Magnitude is selected the magnitude of the complex vector is computed as M R I n n n 2 2 Steps 1 6 lead to the following result An AC sine wave of amplitude 1 0 V with an integral number of periods Np in the time window transformed with the rectangular window results in a fundamen...

Страница 229: ...ggested in the above formula dBm Power Density dBm PD dBmPS ENBW f 10 10 log where ENBW is the equivalent noise bandwidth of the filter corresponding to the selected window and f is the current frequency resolution bin width 7 The FFT Power Average takes the complex frequency domain data R n and I n for each spectrum generated in Step 5 and computes the square of the magnitude Mn 2 R n 2 I n 2 the...

Страница 230: ...ze should be selected so that the resulting Nyquist frequency is higher than the highest significant component in the time domain record Coherent Gain The normalized coherent 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 i...

Страница 231: ...onic components of the input signal For a real source waveform imaginary part equals 0 there are only N 2 independent harmonic components An FFT corresponds to analyzing the input signal with a bank of N 2 filters all having the same shape and width and centered at N 2 discrete frequencies Each filter collects the signal energy that falls into the immediate neighborhood of its center frequency and...

Страница 232: ...nt has a lower and broader peak The broadening of the base of the peak stretching out into many neighboring bins is termed leakage It is due to the relatively high side lobes of the filter associated with each frequency bin The filter side lobes and the resulting leakage are reduced when one of the available window functions is applied The best reduction is provided by the Blackman Harris and Flat...

Страница 233: ...r spectrum divided by the equivalent noise bandwidth of the filter in hertz The power density spectrum is displayed on the dBm scale with 0 dBm corresponding to Vref2 Hz Sampling Frequency The time domain records are acquired at sampling frequencies dependent on the selected time base Before the FFT computation the time domain record may be decimated If the selected maximum number of points is low...

Страница 234: ... pp 41 52 A general introduction to FFT theory and applications Brigham E O The Fast Fourier Transform Prentice Hall Inc Englewood Cliffs N J 1974 Theory applications and implementation of FFT Includes discussion of FFT algorithms for N not a power of 2 Harris F J On the Use of Windows for Harmonic Analysis with the Discrete Fourier Transform Proceedings of the IEEE vol 66 No 1 January 1978 pp 51 ...

Страница 235: ...l spanned by the left and right time cursors For example the histogram of a waveform transitioning in two states will contain two peaks Fig D 1 The analysis will attempt to identify the two clusters that contain the largest data density Then the most probable state centroids associated with these two clusters will be computed to determine the top and base reference levels the top line corresponds ...

Страница 236: ...me interval separating the points on the rising or falling edges is then estimated to yield the rise or fall time These results are averaged over the number of transition edges that occur within the observation window Rising Edge Duration Mr i i i Tr Tr Mr 1 10 90 1 Falling Edge Duration Mf i i i Tf Tf Mf 1 90 10 1 Where Mr is the number of leading edges found Mf the number of trailing edges found...

Страница 237: ...urate differential time measurements between two traces for example propagation setup and hold delays Fig D 3 Parameters such as c2d require the transition polarity of the clock and data signals to be specified RIGHT CURSOR LEFT CURSOR TWO FULL PERIODS 2 cycles first last 50 delay PERIOD PERIOD cmean cmedian crms csdev computed on interval periods width width width freq period 1 duty width period ...

Страница 238: ...terval separating the rising edge of the clock trigger from the first negative transition of the data signal Similarly c2d 1 2 measures the time interval between the trigger and the next transition of the data signal RIGHT CURSOR LEFT CURSOR TRIGGER POINT DATA 1 CLK 2 THRESHOLD CLOCK EDGE Positive Transition DATA EDGE Negative Transition HYSTERESIS Noisy spikes ignored due to Hysteresis band c2d 1...

Страница 239: ...iangle or saw tooth waves for example returns same value as min cycles Determines number of cycles of a periodic waveform lying between cursors First cycle begins at first transition after the left cursor Transition may be positive or negative going Number of cycles of periodic waveform See Fig D 2 cmean Cyclic mean Computes the average of waveform data Contrary to mean computes average over an in...

Страница 240: ... delay of other Time between trigger and first 50 crossing after left cursor See Fig D 2 dly delay Computes time between 50 level of two sources Time between midpoint transition of two sources t lv t at level Computes transition between selected levels or sources Time between transition levels of two sources or from trigger to transition level of a single source Reference levels and edge transitio...

Страница 241: ...s triangle or saw tooth waves for example top and base can default to maximum and minimum giving however less predictable results f level Fall at level Duration of pulse waveform s falling edges between transition levels Duration of falling edge between transition levels On signals NOT having two major levels triangle or saw tooth waves for example top and base can default to maximum and minimum g...

Страница 242: ... of the right cursor and first will give the location of the cursor formerly on the right now on left freq Frequency Period of cyclic signal measured as time between every other 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 See Fig D 2 last Time from trigger t...

Страница 243: ...e contributions from more than one acquisition median The average of base and top values Average of base and top See Fig D 2 minimum Measures the lowest point in a waveform Unlike base does NOT assume waveform has two levels Lowest value in waveform between cursors See Fig D 1 Gives similar result when applied to time domain waveform or histogram of data of same waveform But with histograms result...

Страница 244: ...tween signal and reference points Number of points in the waveform between the cursors Number of points between cursors See Fig D 2 r20 80 Rise 20 to 80 Duration of pulse waveform s rising transition from 20 to 80 averaged for all rising transitions between the cursors Average duration of rising 20 80 transition On signals NOT having two major levels triangle or saw tooth waves for example top and...

Страница 245: ...same waveform But with histograms result may include contributions from more than one acquisition Where videnotesmeasuredsample values and N number of data points within the periods found up to maximumof100periods sdev Standard deviation of the data between the cursors about the same as rms for a zero mean waveform N i i mean v N 1 2 1 See Fig D 2 Gives similar result when applied to time domain w...

Страница 246: ... may include contributions from more than one acquisition width Width of cyclic signal determined by examining 50 crossings in data input If first transmission after left cursor is a rising edge waveform is considered to consist of positive pulses and widththe time between adjacent rising and falling edges Conversely if falling edge pulses are considered negative and width the time between adjacen...

Страница 247: ...les of the use of each format are given on the following pages Format Header Format includes some form of header before the data Time Values Format stores time values with each amplitude value Amplitude Values Format stores amplitude values Sequence Times Header contains sequence time information for each sequence segment Multi Segment Format concatenates multiple segments of a sequence waveform D...

Страница 248: ...Microsoft Excel Version 7 0 for Windows A waveform stored in Spreadsheet format may be read into Microsoft Excel using the File Open dialog as follows Excel will now ask for more information about the file type Ensure that the Delimited option is selected in the first step of the Wizard ...

Страница 249: ...E 3 ASCII Waveform Export The next step allows the specific delimiter to be specified The Spreadsheet format generated by the scope uses a comma to delimit columns Ensure that this is selected ...

Страница 250: ...d and final step allows the format of the columns to be specified The general format for each column should be used this is the default After clicking the Finish button a display similar to that following should be displayed ...

Страница 251: ...may be used to extract information such as the start and end row of the data for a given segment or the trigger time of a given segment SegmentStartRow DesiredSegment D2 B2 5 SegmentEndRow SegmentStartRow D2 1 TrigTime INDIRECT ADDRESS DesiredSegment 3 2 4 TimeSinceFirstTrig INDIRECT ADDRESS DesiredSegment 3 3 4 Plotting the data from all segments using a scatter plot will result in all segments o...

Страница 252: ...E 6 Appendix E ...

Страница 253: ...indows On this and the next page the procedure for reading and graphing a file for a single segment is shown using Mathcad Versions 3 1 and 7 respectively The example on page E 9 is for multiple segments Single Segment Version 3 1This single segment example illustrates the use of Mathcad Version 3 1 ...

Страница 254: ...ngle Segment Version 7 This single segment example is valid for more recent versions of Mathcad A READPRN file K last A 0 A submatrix A 2 K 0 1 t A 0 v A 1 K last t k 0 K 1 v k t k 0 001 0 0 001 0 002 0 003 0 004 1 0 1 ...

Страница 255: ...lti Segment Example The following Mathcadexample demonstrates how to extract data from a given segment The data used for this example consisted of two segments of three samples each allowing the entire imported matrix to be shown ...

Страница 256: ...ATLAB Version 4 2c 1 for Windows Reading and graphing a waveform in MATLABmay be achieved with two simple commands as the following example shows The first command loads the file into a matrix which is automatically named after the file The second command plots this matrix ...

Страница 257: ... the file is written scopeid scopeserial Segments numseg SegmentSize numpts Segment TrigTime TimeSinceFirstSegment 1 trigtime 1 0 0 numseg trigtime numseg trigdelta numseg Time Ampl Ampl1 x 0 y 0 y1 0 x 1 y 1 y2 0 x numgseg numpts y numseg numpts y1 numseg numpts Single Segment Example LECROY9354 935412345 Segments 1 SegmentSize 502 Segment Trig Time TimeSinceFirstSegment 1 21 Mar 1990 9 37 08 0 0...

Страница 258: ...ray Example LECROY9354 935412345 Segments 1 SegmentSize 502 Segment Trig Time TimeSinceFirstSegment 1 21 Mar 1990 9 37 08 0 0 Time Ampl 0 0 1 1 1 1 0 1 2 1 2 1 Note Ø The basic structure of the Spreadsheet format is a header containing scope identification information followed by a block containing trigger times for multi segment waveforms followed by the data itself Ø This format is compatible wi...

Страница 259: ...egment TimeSinceFirstSegment 1 0 0 numseg trigdelta numseg Time Ampl Ampl1 x 0 y 0 y1 0 x 1 y 1 y1 1 x numgseg numpts y numseg numpts y1 numseg numpts Single Segment Example LECROY9354 935412345 23 March 90 12 44 23 1 502 Segment TimeSinceFirstSegment 1 0 0 Time Ampl 0 0 1 0 1 2 ...

Страница 260: ...ilar to the Spreadsheet format but with some differences due to the way MathCad interprets the header information Ø One of the most important of these is that the absolute trigger time is only given for the first segment with relative times in units of seconds being included for each segment Ø Another difference is that the scope identification and trigger time are wrapped in quotes to ensure that...

Страница 261: ...le Segment Example 1 0 1 1 1 2 4 5 Notes Ø The MATLAB format is simple without header information and having amplitude values only Ø Multiple segments will be appended without a separator Ø Only one value from the pair of amplitude values present in a dual array will be stored ...

Страница 262: ... 6 A 13 A 19 A 26 E 1 E 2 E 3 E 4 E 5 E 9 E 10 E 11 E 12 E 13 E 14 E 15 AUTO 6 2 7 9 AUTO SETUP 4 3 6 1 9304C 9310C 9314C Series A 3 9344C 9350C 9354C Series A 11 9370C 9374C Series A 17 9384C Series A 23 Auto Calibration 12 19 9304C 9310C 9314C Series A 6 9344C 9350C 9354C Series A 13 9370C 9374C Series A 19 9384C Series A 26 Auto Store 12 9 13 2 Average Setup 10 9 Averaging B 3 B Bandwidth 5 3 5...

Страница 263: ...CTIVE menu 16 5 CLEAR SWEEPS 4 7 10 3 10 4 10 13 11 7 14 6 14 7 14 8 Clock 9304C 9310C 9314C Series A 2 9344C 9350C 9354C Series A 9 9370C 9374C Series A 16 9384C Series A 22 Clock Edge 14 12 D 4 Coherent Gain C 17 Combining Channels 2 1 7 4 7 5 7 8 10 5 Conformity 3 1 Continuous Averaging 10 3 10 9 Controls Menu buttons and knobs 4 3 COPY FILES 12 18 Copying files between storage media 12 10 Coup...

Страница 264: ...0C 9354C Series A 7 9384C Series A 21 Directory 12 7 12 11 12 15 12 16 12 17 Disk Density 12 13 Display 2 2 9304C 9310C 9314C Series A 4 9344C 9350C 9354C Series A 11 9370C 9374C Series A 17 9384C Series A 24 on screen sections and fields 4 9 Standard Persistence 11 7 DISPLAY 4 6 11 1 11 6 11 7 Display Scaling 10 19 Display Setup 11 1 Persistence 11 7 Displayed Trace Label 4 9 10 3 10 19 11 1 Dist...

Страница 265: ...st Fourier Transform menus 10 12 10 13 FFT Algorithms C 14 FFT Average Setup 10 13 FFT Error Messages C 13 FFT Interruption 10 12 FFT result menu C 10 C 11 FFT Span 10 17 10 18 10 19 10 20 10 21 FFT Windows 10 12 C 5 C 6 C 11 C 17 C 19 C 20 Fields 8 34 File 13 5 14 19 File Deleting 12 9 File Naming 12 8 12 9 12 15 12 16 File Transfers 12 10 Files 12 7 12 9 12 10 12 12 12 14 12 18 15 3 Fill 12 9 Fi...

Страница 266: ...s 11 9 Dual 11 3 Parameter Display 11 4 Quad 11 3 selecting 11 6 11 7 Single 11 2 XY Dual 11 5 XY only 11 4 XY Single 11 5 Ground and Trace Level markers 4 9 H Hard Disk 12 7 12 10 12 14 12 15 13 1 13 2 13 5 14 19 15 1 15 2 Hardcopy 2 2 9304C 9310C 9314C Series A 6 9344C 9350C 9354C Series A 13 9370C 9374C Series A 19 9384C Series A 26 Expansion factor 12 3 Hardcopy Setup 12 1 12 2 12 3 Harmonics ...

Страница 267: ...C 5 C 11 C 19 LEVEL 6 3 8 1 LINE 8 4 Lobes C 2 C 5 C 17 C 19 Low Frequency Triggering 8 5 Low pass Filtering B 2 B 4 C 6 M Magnitude C 4 C 6 C 10 C 15 C 16 Maintenance 1 2 Mask Testing 14 13 14 17 14 18 14 19 Mass Storage 12 7 12 15 12 16 12 18 MASS STORAGE 12 10 12 12 12 14 Math Functions 9 1 10 2 10 6 10 14 10 17 10 18 10 19 Speeding them up 10 5 MATH SETUP 9 2 Math Type menu C 11 Mathcad E 1 E ...

Страница 268: ...314C Series A 1 9344C 9350C 9354C Series A 8 9370C 9374C Series A 15 9384C Series A 21 Offset scaling 6 1 Operand 10 8 Operating Environment 3 1 A 6 A 13 A 19 A 26 Operator 10 8 Options installed information on 16 2 OR interval 8 32 Output Formats A 6 A 13 A 19 A 26 Over D 9 Over D 9 Overflow B 3 Overload 3 3 5 3 5 5 Oversampling B 1 Overvoltage 3 1 P Packing and Shipment 1 3 PANEL SETUPS 4 7 15 1...

Страница 269: ...C Series A 6 9344C 9350C 9354C Series A 13 9370C 9374C Series A 19 9384C Series A 26 Power Average C 16 Power Averaging 10 13 Power Density 10 12 C 10 C 16 Power Density Spectrum C 4 C 20 Power On Self Test 3 3 Power Spectrum 10 12 C 4 C 10 C 16 C 20 Precise Timing Measurements 10 1 Pre Trigger 6 3 Printers 12 2 12 3 12 5 9304C 9310C 9314C Series A 5 9344C 9350C 9354C Series A 13 9370C 9374C Serie...

Страница 270: ...mpling 2 2 7 1 7 2 7 5 8 27 9304C 9310C 9314C Series A 2 9370C 9374C Series A 15 9384C Series A 22 AUTO 6 2 SNGL 6 3 STOP 6 2 Rise D 2 Rise 20 80 D 10 Rise at Level D 10 Rise time 14 7 D 2 D 10 Rising edge 14 11 Roll Mode 7 1 7 3 9304C 9310C 9314C Series A 2 9344C 9350C 9354C Series A 9 9370C 9374C Series A 16 9384C Series A 22 AUTO 6 2 NORM 6 2 SNGL 6 3 STOP 6 2 Roof 10 11 in extrema waveforms 10...

Страница 271: ...NR ratio improving it using Enhanced Resolution Filtering B 1 B 2 SINGLE 7 8 Single Shot Acquisition 10 3 Single Shot Aquisition 7 1 Single Shot Mode 6 3 7 5 Size 9304C 9310C 9314C Series A 6 9344C 9350C 9354C Series A 13 9370C 9374C Series A 19 9384C Series A 26 SMART Trigger 8 1 8 2 8 10 8 11 8 12 8 13 8 14 8 15 8 16 8 17 8 18 8 19 8 20 8 21 8 22 8 24 8 25 8 27 8 29 8 30 8 31 8 32 8 33 8 34 8 35...

Страница 272: ...Date Setup 12 1 TIME DIV 6 3 Timebase 8 6 14 17 16 1 9304C 9310C 9314C Series A 2 9344C 9350C 9354C Series A 9 9370C 9374C Series A 15 9384C Series A 22 TIMEBASE 6 1 10 18 10 20 TIMEBASE TRIGGER 4 3 Timebase Clock 7 1 Timebase scaling 6 1 TIMEBASE SETUP 6 4 7 5 Timebase Source 6 1 Timebase summary 16 1 Timeout 8 6 8 37 Time outs 8 27 tolerance 14 18 Top D 1 D 2 D 11 Trace and Ground Level markers ...

Страница 273: ...RSETUP 6 4 8 29 TRIGGER SETUP 8 1 TRIGGER SETUP menus 8 1 Trigger Signal Interval 9304C 9310C 9314C Series A 3 Trigger Signal or Pattern Interval 9344C 9350C 9354C Series A 10 9370C 9374C Series A 16 9384C Series A 23 Trigger Signal or Pattern Width 9304C 9310C 9314C Series A 3 9344C 9350C 9354C Series A 10 9370C 9374C Series A 16 9384C Series A 23 Trigger Slope 8 5 8 9 8 37 9304C 9310C 9314C Seri...

Страница 274: ...C 9374C Series A 15 9384C Series A 22 increasing it B 5 Vertical Sensitivity 5 1 VOLTS DIV 5 1 5 2 Volts div scaling 6 1 W Warnings 3 2 Warranty 1 1 A 6 A 13 A 19 A 26 Waveform and Text intensity 11 6 11 7 11 9 Waveform Mathematics 10 2 10 5 10 6 Waveform Processing 10 5 C 1 C 7 C 11 C 12 C 14 C 17 C 18 Waveform Recall 13 4 13 5 WAVEFORM RECALL 4 6 Waveform Status 16 4 Waveform Store 13 1 13 3 WAV...

Страница 275: ...Index 9370C 9374C Series A 18 9384C Series A 24 Zoom menu 10 7 Zoom of Math Functions 10 1 ...

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