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HP 54750A User Manual Download Page 235

Increasing

Measurement

A

ccuracy

Measuring

time

intervals

In

this

section,

we

discuss

measuring

a

pulse

width

to

show

the

principles

of

time-interval

measurement.

The

time

interval

you

want

to

measure

might

be

a

setup

time

,

a

propagation

delay

,

or

a

rise

time

.

However

,

all

time-interval

measurements

made

with

instruments

are

similar

.

In

all

cases

you

measure

the

time

between

two

events

,

where

an

event

is

dened

as

a

voltage

transition

of

a

specied

polarity

through

a

specied

level.

When

measuring

the

width

of

a

pulse

,

these

two

events

are

the

leading

edge

and

the

trailing

edge

.

The

concepts

developed

here

can

be

applied

to

any

other

time-interval

measurement.

F

or

two-channel

measurements

,

you

must

take

care

to

deskew

the

two

channels

.

Refer

to

\Channel-to-channel

measurements",

later

in

this

chapter

,

for

more

information.

9-3

Summary of Contents for 54750A

Page 1: ...User s Guide HP 83480A Analyzer HP 54750A Oscilloscope ...

Page 2: ...uential damages in connection with the furnishing performance or use of this material Restricted Rights Legend Use duplication or disclosure by the U S Government is subject to restrictions as set forth in subparagraph c 1 ii of the Rights in Technical Data and Computer Software clause at DFARS 252 227 7013 for DOD agencies and subparagraphs c 1 and c 2 of the Commercial Computer Software Restrict...

Page 3: ...rd It calls attention to a procedure which if not correctly performed or adhered to could result in injury or loss of life Do not proceed beyond a warning sign until the indicated conditions are fully understood and met Instruction Manual L The instruction manual symbol The product is marked with this symbol when it is necessary for the user to refer to the instructions in the manual CE The CE mar...

Page 4: ...rmal condition in which all means for protection are intact only WARN ING For continued protection against re hazard replace line fuse only with same type and ratings type nA nV The use of other fuses or materials is prohibited WARN ING The power cord is connected to internal capacitors that may remain live for 5 seconds after disconnecting the plug from its power supply CAUT ION Before this instr...

Page 5: ...nput circuits can be damaged by electrostatic discharge ESD Repair of damage due to misuse is not covered under warranty Therefore avoid applying static discharges to the front panel input connectors Before connecting any coaxial cable to the connectors momentarily short the center and outer conductors of the cable together Avoid touching the front panel input connectors without rst touching the f...

Page 6: ...NOTE Clean the cabinet using a damp cloth only vi ...

Page 7: ...X Ray Radiation Notice vii ...

Page 8: ...Declaration of Conformity viii ...

Page 9: ...f Conformity EMC Product Speci cation Performance Code IEC 801 2 1991 EN 50082 1 1992 4kV CD 8kV AD PASS Temporary degradation self recoverable IEC 801 3 1984 EN 50082 1 1992 3 V m 1 kHz 80 AM 27 1000 MHz PASS Temporary degradation self recoverable IEC 801 4 1988 EN 50082 1 1992 0 5 kV Sig Lines 1kV Power Lines PASS Normal operation no e ect ix ...

Page 10: ...NNNNNNN Softkey This indicates a softkey a key whose label is determined by the rmware of the instrument Screen Text This indicates text displayed on the instrument s screen WARN ING This symbol will appear along with bold print to highlight a warning CAUT ION This symbol will appear when special care is required x ...

Page 11: ...t from the factory Hewlett Packard further certi es that its calibration measurements are traceable to the United States National Institute of Standards and Technology to the extent allowed by the Institute s calibration facility and to the calibration facilities of other International Standards Organization members xi ...

Page 12: ... instrument will execute its programming instructions when properly installed on that instrument Hewlett Packard does not warrant that the operation of the instrument or software or rmware will be uninterrupted or error free Limitation of Warranty The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by Buyer Buyer supplied software or interfacing unau...

Page 13: ...ure and error messages along with the instrument being returned Please notify the service o ce before returning your instrument for service Any special arrangements for the instrument can be discussed at this time This will help the HP service o ce repair and return your instrument as quickly as possible The original shipping containers should be used If the original materials were not retained id...

Page 14: ...55 1500 Illinois Hewlett Packard Company 5201 Tollview Drive Rolling Meadows IL 60008 708 342 2000 New Jersey Hewlett Packard Company 150 Green Pond Road Rockaway NJ 07866 201 586 5400 Texas Hewlett Packard Company 930 East Campbell Road Richardson TX 75081 214 231 6101 EUROPEAN FIELD OPERATIONS Headquarters Hewlett Packard S A 150 Route du Nant d Avril 1217 Meyrin 2 Geneva Switzerland 41 22 780 8...

Page 15: ...00 South Service Road Trans Canada Highway Kirkland Quebec H9J 2X8 Canada 514 697 4232 China China Hewlett Packard Company 38 Bei San Huan X1 Road Shuang Yu Shu Hai Dian District Beijing China 86 1 256 6888 Japan Yokogawa Hewlett Packard Ltd 1 27 15 Yabe Sagamihara Kanagawa 229 Japan 81 427 59 1311 Singapore Hewlett Packard Singapore Ltd Pte Ltd Alexandra P O Box 87 Singapore 9115 65 271 9444 Taiw...

Page 16: ...e oor mat and heel strap combination Both types when used together provide a signi cant level of ESD protection Of the two only the table mat and wrist strap combination provides adequate ESD protection when used alone To ensure user safety the static safe accessories must provide at least 1 M of isolation from ground Refer to Table 0 1 for information on ordering static safe accessories WARN ING ...

Page 17: ...Figure0 1 Exampleof astatic safeworkstation xvii ...

Page 18: ...fe accessories that can be obtained from Hewlett Packard using the HP part numbers shown Table 0 1 Static SafeAccessories HP Part Number Description 9300 0797 Set includes 3M static control mat 0 6 m 2 1 2 m 2 ft 2 4 ft and 4 6 cm 15 ft ground wire The wrist strap and wrist strap cord are not included They must be ordered separately 9300 0980 Wrist strap cord 1 5 m 5 ft 9300 1383 Wrist strap color...

Page 19: ...binations jackets and indexes of refraction In general di erent types of cables do not work well together Cables should match each other and the system However regardless of the cable type the connectors have only one function to provide a direct and low loss optical signal transition from one ber end to another When these connectors are used in a measurement system repeatability becomes an import...

Page 20: ...re ections caused by damaged worn or loose ber ends and the improper use and removal of index matching compounds Achieving the best possible connection where the ber end faces are ush no air gap and properly aligned depends on two things 1 the type of connector 2 using the proper cleaning and connecting techniques If the connection is lossy or re ective light will not make a smooth transition If t...

Page 21: ...tical ber Used to mate two optical connectors Handling Always handle lightwave connectors and cable ends with great care Fiber ends should never be allowed to touch anything except other mating surfaces or cleaning solutions and tools Always keep connectors and cable ends covered with a protective cap when they are not in use See Storage Cleaning Two cleaning processes are provided The rst process...

Page 22: ...r Then use alcohol to clean the ber end Some amount of wiping or mild scrubbing of the ber end can help remove particles when application of alcohol alone will not remove them This can be done by applying the alcohol to a cotton swab and moving it back and forth across the ber end several times This technique can help remove or displace particles smaller than one micron Allow the connector to dry ...

Page 23: ... either laser shutter caps or dust caps on the lightwave adapters that come with the instrument Also all of the cables that are shipped have covers to protect the cable ends from damage or contamination These dust caps and protective covers should be kept on the equipment except when in use Making connections Proper connection technique requires attention to connector compatibility insertion techn...

Page 24: ...ment and nonrepeatable measurements Always nger tighten the connector in a consistent manner Refer to the manufacturer s data sheet for any torque recommendations CAUTION OPTION 3XX INSTRUMENTS To avoid damage handle the pigtail ber with care Use only an appropriate ber cleaver tool for cutting the ber Do not pull the bare ber out of its jacket crush it kink it or bend it past its minimum bend rad...

Page 25: ...tical performance testing Introduction Consistent measurements with your lightwave equipment are a good indication that you have good connections However you may wish to know the insertion loss and or return loss of your lightwave cables or accessories If you test your cables and accessories for insertion loss and return loss upon receipt and retain the measured data for comparison you will be abl...

Page 26: ...ropriate source receiver and lightwave coupler an HP 8504B precision re ectometer an HP 8153A lightwave multimeter and HP 81534A return loss module Many other possibilities exist The basic requirements are an appropriate lightwave source a compatible lightwave receiver and a compatible lightwave coupler Refer to the manuals provided with your lightwave test equipment for information on how to perf...

Page 27: ...e mask and eyeline measurement tutorials Chapter 6 describes the mask test measure eye channel setup time base and trigger menus Part 3 Digitizing Oscilloscope Functions Chapter 7 describes the automatic waveform measurement process Chapter 8 describes how to use the built in automatic measurements Chapter 9 describes how to increase measurement accuracy and how to make time interval measurements ...

Page 28: ......

Page 29: ...ine Function 2 4 The Help Key 2 5 The Local Key 2 6 The Run Key 2 7 The Stop Single Key 2 8 3 Speci cations and Characteristics Horizontal system 3 3 Trigger speci cations electrical and optical channels 3 4 Standard instrument 2 5 GHz mode 3 4 Option 100 12 GHz mode 3 5 Option 100 12 GHz Gate mode 3 5 General speci cations 3 6 4 Calibration Overview Mainframe Calibration 4 3 Plug in Module Calibr...

Page 30: ...rd Mask 5 32 Making Eyeline Measurements HP 83480A Option 001 only 5 37 Eyeline traces 5 38 Noise reduction 5 40 Error trace capture 5 42 Equipment con guration program installation 5 43 Error trace capture 5 48 6 The Digital Communications Analysis Menus Mask Test Menu 6 3 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Scale Mask 6 19 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Mask Align 6 21 NNNNNNNNNNNNNNNNNNNNNNNNNNN...

Page 31: ...NNNNNNNNNNNNNNNN Window Position 6 49 Trigger Menu 6 50 Trigger Basics 6 50 NNNNNNNNNNNNNNNNN Sweep 6 51 NNNNNNNNNNNNNNNNNNNN Source 6 51 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN External Scale 6 52 NNNNNNNNNNNNNNNNN Level 6 52 NNNNNNNNNNNNNNNNN Slope 6 52 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Hysteresis 6 53 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Trig Bandwidth 6 53 7 Waveform Measurements H...

Page 32: ...y Cycle 8 6 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Fall Time 8 7 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Frequency 8 7 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Overshoot 8 7 NNNNNNNNNNNNNNNNNNNN Period 8 8 NNNNNNNNNNNNNNNNNNNNNNNNNN Preshoot 8 8 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Rise Time 8 8 NNNNNNNNNNNNNN Vamp 8 9 NNNNNNNNNNNNNNNNN Vbase 8 9 NNNNNNNNNNN Vpp 8 9 NNNNNNNNNNNNNN Vrms 8 10 NNNNNNNNNNNNNN Vtop 8 10 General Meas Menu ...

Page 33: ...NNNNNNNNNNN 62 8 19 NNNNNNNNNNNNNNN 63 8 20 NNNNNNNNNNNNNN hits 8 20 NNNNNNNNNNNNNN mean 8 20 NNNNNNNNNNNNNNNNNNNN median 8 21 NNNNNNNNNNNNNN peak 8 21 NNNNNNNNNNNNNNNNN pk pk 8 21 NNNNNNNNNNNNNNNNNNNNNNN std dev 8 22 9 Increasing Measurement Accuracy and Time Interval Measurement Increasing Measurement Accuracy 9 3 Measuring time intervals 9 3 Automatic measurements 9 4 Markers 9 5 Channel to cha...

Page 34: ...NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Edge Threshold 10 15 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Color grade 10 16 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Signal type 10 16 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Eye window 1 and NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Eye window 2 10 17 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Meas Complete 10 18 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Statistics ...

Page 35: ...10 46 NNNNNNNNNNNNNNNNNNNNNNNNNN Function 10 47 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Define Function 10 47 NNNNNNNNNNNNNNNNNNNNNNN Display 10 51 Time Base Menu 10 53 NNNNNNNNNNNNNNNNN Units 10 54 NNNNNNNNNNNNNNNNNNNNNNNNNN Bit rate 10 54 NNNNNNNNNNNNNNNNN Scale 10 55 NNNNNNNNNNNNNNNNNNNNNNNNNN Position 10 55 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Reference 10 56 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN...

Page 36: ...NNNNNNNNNNNNNNNNNNNNN Mask Formats 11 21 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN From File NNNNNNNNNNNNNNNNNNNNNNN To File or NNNNNNNNNNNNNNNNNNNNNNNNNNNNN File Name 11 22 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN To memory 11 23 Display Menu 11 24 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Persistence 11 25 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Color grade 11 27 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN draw waveform ...

Page 37: ...NNNNNNNNNNNNNNNNNNNNNNNNNNN Default setup 11 66 Setup Print Menu 11 70 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Print format 11 72 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Destination 11 74 NNNNNNNNNNNNNN Data 11 76 TIFF and GIF les on the Apple Macintosh Computer 11 77 Utility Menu 11 78 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN HP IB Setup 11 79 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Sys...

Page 38: ...ture 13 8 The major plug in module hardware components 13 9 The major mainframe hardware components 13 10 Probe selection 13 12 System bandwidth 13 17 Probe types 13 18 Summary 13 21 Standard and Enhanced Trigger Modes 13 22 DC 2 5 GHz mode 13 22 DC 100 MHz mode 13 22 2 12 GHz mode Option 100 only 13 23 12 GHz Gate mode Option 100 only 13 25 Index Contents 10 ...

Page 39: ...5 28 5 14 Eye with a mask 5 32 5 15 Mask with a 20 margin set 5 35 5 16 Conventional eye diagram display 5 38 5 17 Similar eye diagram in eyeline mode 5 39 5 18 Conventional eye diagram of a low power signal 5 40 5 19 Low power signal viewed with eyeline mode using averaging 5 41 5 20 Mask violation and the sequence leading to the violation 5 42 5 21 Front panel connection for eyeline mode 5 43 5 ...

Page 40: ... reinforce dc errors 9 11 9 4 Faster transitions decrease e ect of dc o set errors 9 12 9 5 Measure time intervals at fastest changing part of transition 9 12 9 6 Narrow pulse applied to the instrument 9 16 9 7 Errors in pulse height measurement 9 17 9 8 Error in pulse width at 10 level is approximately equal to the error in 10 90 rise time 9 18 9 9 E ect of probe capacitance 9 19 10 1 Standard me...

Page 41: ...pacitance 13 15 13 10 Resistive divider probe 13 18 13 11 Active probe 13 20 13 12 Viewing a 10 Gb s eye diagram using 12 GHz trigger 13 24 13 13 12 GHz mode jitter with 200 mV p p sine wave input 13 26 13 14 12 GHz Gate mode jitter with 300 mV p p sine wave input 13 27 13 15 Gating application 13 28 13 16 2 5 GHz trigger on signal with pulsed 2 GHz RF content 13 29 13 17 12 GHz trigger on signal ...

Page 42: ...Accessories xviii 9 1 Rise Time Measurement Errors 9 15 11 1 Partial listing of the Text Verbose Format for a Normal Waveform 11 16 11 2 Partial Example of the Text Y Values Format 11 20 11 3 Default Setups 11 67 Contents 14 ...

Page 43: ...1 The Instrument at a Glance ...

Page 44: ...s used in this manual The following topics are discussed options and accessories menu and key conventions the front panel and rear panel the display indicator lights entry devices keys that do not display menus on screen Understanding the information in this chapter will help you operate the instrument Information on using the front panel interface is in the User s Quick Start Guide supplied with ...

Page 45: ...try standard eye diagram masks or pulse templates are e ciently executed The instrument is a modular platform which accepts up to two dual channel electrical or optical measurement modules The instrument provides you with the necessary capabilities to test and measure analog and digital circuits The instrument provides Optical and electrical measurement channels HP 83480A only Optical input wavele...

Page 46: ...TS1 Eye STM1 OC3 STS1 Pulse OC12 STS3 Eye OC24 STS3 Pulse 0 STM16 OC48 STS3 Pulse 1 FC133 DS1 FC266 DS1C FC531 DS2 FC1063 DS3 FDDI PDH 2 048 Mb 100BASE FX PDH 8 448 Mb GIGABIT ETHERNET PDH 34 4 Mb PDH 139 Mb 0 PDH 139 Mb 1 Automatic mask and template scaling positioning and testing Statistical waveform analysis FFT 1 4 ...

Page 47: ...bilities Option 908 Rackmount kit without handles HP p n 54710 68704 Option 909 Rackmount kit for instruments with handles HP p n 54710 68705 Option 0BW Service guide Option 0B1 Additional set of user documentation Option 0B0 Deletes the user documentation Option UK6 Measured performance data Optional accessories HP 10086A ECL terminator HP 11898A extender module HP 54006A 6 GHz divider probe HP 5...

Page 48: ...P 83486A 1300 1500 nm multimode optical electrical plug in module HP 83487A 850 nm multimode optical electrical plug in module Blank one 1 slot ller plug in HP part number 54700 68702 or HP 54700B Connectiondevices SMA f f adapter HP part number 1250 1158 APC 3 5 f f adapter HP part number 1250 1749 1 6 ...

Page 49: ...ion press the blue front panel Shift key and the front panel key next to the desired function Throughout this manual front panel keys are indicated by a box around the key label for example 4Timebase5 Softkeys are indicated by shading on the key label for example NNNNNNNNNNNNNNNNN Scale The softkeys displayed depend on the front panel key pressed and which menu is selected Shifted functions are in...

Page 50: ...Freerun is highlighted A choices softkey will be indicated throughout this manual as NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Sweep Triggered Freerun Triggered When some softkeys such as NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Eye Height are pressed the rst time a measurement will be made and the result will be provided Some softkeys such as NNNNNNNNNNNNNNNNNNNN Offset requ...

Page 51: ...area and several functional areas including Control Measure Setup Storage System Autoscale Figure1 1 Theinstrument frontpanel The display area and Autoscale key are described in this chapter Information on the other functional areas are included later in this manual 1 9 ...

Page 52: ...s HP 83480A Option 100 only If no trigger signal is detected at the external input and the instrument is in the 2 5 GHz trigger mode the sweep will stop If the instrument is in the 12 GHz trigger mode it will sweep continuously in freerun condition If the Autoscale key is pressed unintentionally use the Undo Autoscale function to return the instrument to the settings that existed prior to pressing...

Page 53: ...The Instrument at a Glance TheFront Panel Display The instrument has a high resolution color display The display is divided into several areas as shown in Figure 1 2 Figure 1 2 Theinstrumentdisplay 1 11 ...

Page 54: ...on 20 ns ChannelSettingsand MeasurementResults area Channel Settings and Measurement Results share the same area Channel Settings are displayed only when the measurements are o When making an automatic measurement the results are displayed in place of the channel settings To display the Channel Settings press 4Shift5 NNNNNNNNNNNNNNNNNNNNNNNNNN Clr Meas When a channel number is displayed it indicat...

Page 55: ...ay When possible the acquisition hardware is set up so all of the waveform record is displayed on the screen When the acquisition is stopped and the waveform is magni ed with the time base controls the memory bar indicates which portion of the waveform is viewed Entry devices The entry devices are the knob the arrow keys the keypad You can use the entry devices to change the numeric settings of so...

Page 56: ...n sampled to ll the record length a trace is completed The triggered light can be used to help determine the trigger thresholds To do this simply move the trigger level in either direction When the triggered light turns o you know that is one of the trigger thresholds Move the trigger level in the other direction to determine the other threshold You now know what the trigger thresholds are and you...

Page 57: ...The Rear Panel Figure1 3 Theinstrument rearpanel 1 15 ...

Page 58: ... fuse can be replaced with one of the following values 100V operation F15A 250V HP part number 2110 0054 120V operation F12A 250V HP part number 2110 0249 240V operation F8A 250V HP part number 2110 0342 LineSelect The Line Select switch adapts the instrument to the power source Select either 115 V or 230 V whichever most closely matches the voltage being supplied to the Line Input To change Line ...

Page 59: ...L compatible input allows gating of the 12 GHKz trigger Refer to 2 12 GHz mode Option 100 only in Chapter 13 for additional information Memory Protect Frame Cal protected Up position prevents timebase calibration from being overwritten switch to down position to perform mainframe calibration Best cal protected Not used Forces system ROM programming at power up In down position the operating system...

Page 60: ...TheInstrument ataGlance ...

Page 61: ...2 General Purpose Keys ...

Page 62: ...hischapter The front panel includes the following functions the Clear Display key the Fine function the Help key the Local key the Run key the Stop Single key This chapter describes each of these functions They are listed alphabetically 2 2 ...

Page 63: ...theinstrumentis stopped If the instrument is stopped the display remains cleared of waveform data until the trigger circuit is rearmed and the instrument is triggered Then the new data is displayed and measurements are recalculated When theinstrumentis running If the instrument is running new waveform data is displayed on the next acquisition and all measurements are recalculated 2 3 ...

Page 64: ...el scale in a 1 2 5 sequence such as 10 mV 20 mV and 50 mV When the Fine function is selected the knob changes the channel scale in smaller increments such as 10 0 mV 10 1 mV 10 2 mV To put the instrument in the Fine mode press 4Shift5 NNNNNNNNNNNNNN Fine Repeat the process to exit the Fine mode The screen displays the word FINE at the top right corner of the graticule area when the Fine mode is a...

Page 65: ... either the knob or arrow keys to scroll through the list of features Figure 2 1 TheHelpmenu For example to move a signal vertically on the display look up Channel vertical scale in the Help menu list The middle column instructs you to press the Channel key and the right column instructs you to press the Scale key Features may be listed under di erent names For example you could have also looked f...

Page 66: ... function returns control of the instrument to the front panel This is the only key that is active when the instrument is under remote control The exception occurs when the controller sends a Local Lockout command The Local Lockout command disables the Local function key 2 6 ...

Page 67: ...to display on the screen try the following Press the Autoscale key Make sure a signal is connected to one of the channels and the display for that channel is turned on Make sure the o set does not have the trace clipped o the display Check the trigger setup conditions to make sure the trigger conditions are valid for the signal Set the Trigger Sweep mode to Freerun Freerun forces the instrument to...

Page 68: ...on is stopped Each subsequent press of the Stop Single key rearms the trigger circuit A complete acquisition cycle is performed any measurements are recalculated and the status area of the screen displays the message Acquisition is complete If all of the channels are turned o or if a trigger event is not found the instrument will not acquire any data 2 8 ...

Page 69: ...3 Speci cations and Characteristics ...

Page 70: ...eci cations Speci cations described warranted performance Characteristics Characteristics provide useful nonwarranted information about the functions and performance of the instrument Characteristics are printed in italics Calibration Cycle HP warrants instrument speci cations over the recommended calibration interval To maintain speci cations periodic recalibrations are necessary We recommend tha...

Page 71: ...e o set relative to trigger Minimum 22 ns Maximum 1000 screen diameters or 10 s whichever is smaller Time intervalaccuracy 8 ps 60 1 of reading dual marker measurement Time intervalresolution screen diameter record length or 62 5 fs whichever is larger Time displayresolution 451 points horizontally 3 3 ...

Page 72: ...Hz Sensitivity 40 mV p p at 100 MHz increasing linearly to 200 mV p p at 2 5 GHz Pulsewidth 200 ps 200 mV Bandwidthlimit Trigger bandwidth reduced to approximately 100 MHz with bandwidth limit enabled Maximumtriggersignal 62 Vdc ac peak 16 dBm Jitter 2 5 ps rms 5E 5 2 delay setting at 2 5 GHz with 200 mV source 3 4 ...

Page 73: ...p p from 2 0 GHz to 12 GHz sine wave input Maximum triggersignal 62 Vdc ac peak 16 dBm Jitter 2 ps rms with time delay less than 100 ns Option 100 12 GHz Gate mode For more information on Option 100 triggering refer to Chapter 13 How the Instrument Works located in this book Trigger bandwidth 2 0 GHz 0 12 GHz typical Sensitivity 300 mV p p from 2 0 GHz to 12 GHz sine wave input typical Trigger gat...

Page 74: ...t 35 C 95 F Non operating up to 90 relative humidity at 65 C 149 F Altitude Operating up to 4 600 meters 15 000 ft Non operating up to 15 300 meters 50 000 ft Vibration Operating Random vibration 50500 Hz 10 minutes per axis 0 3 grms Non operating Random vibration 50500 Hz 10 minutes per axis 2 41 grms Resonant search 5 to 500 Hz swept sine 1 octave minute sweep rate 0 75g 5 minute resonant dwell ...

Page 75: ... PowerRequirements Voltage 90 to 132 or 198 to 264 Vac 48 66 Hz Power 1200 VA 650 W Weight approximate Net 24 5 kg 54 lb Shipping 31 8 kg 70 lb Dimensions H 2 W 2 D 238 2 mm 2 433 6 mm 2 637 38 mm 9 378 in 2 17 071 in 2 25 094 in 3 7 ...

Page 76: ...Speci cationsand Characteristics ...

Page 77: ...4 Calibration Overview ...

Page 78: ...schapter This chapter brie y explains the calibration of the instrument It is intended to give you or the calibration laboratory personnel an understanding of the various calibration levels available and how they were intended to be used 4 2 ...

Page 79: ...quired The procedures and equipment needed to perform a mainframe calibration are included in the optional HP 83480A 54750A Service Guide 1 To see the temperature change since the last calibration on the Cal status screen press 4Utility5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Calibrate NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Cal status on The temperature change is displayed as Current Frame Temperature 1 _ C 2 To...

Page 80: ...led The rear panel includes a drawing showing each switches function and protected position To prevent access to the mainframe calibration switch place a sticker over the access hole to this switch Refer to the optional HP 83480A 54750A Service Guide for more details about the mainframe calibration and the position of the rear panel memory protect switches 4 4 ...

Page 81: ...last calibration on the Cal status screen press 4Utility5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Calibrate NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Cal status on 2 To initiate a plug in calibration press 4Utility5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Calibrate NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Calibrate plug in No additional equipment is required to perform a plug in calibration Reference signals are ...

Page 82: ...for matching propagation delay between channels probes cables and so forth using external probes Optical channels have calibration procedures for adjusting timebase skew monitoring and adjusting internal o sets performing a user de ned O E responsivity adjustment Refer to the plug in module user s guide for more information on these calibrations 4 6 ...

Page 83: ...obe calibration is performed 2 If you do not perform a probe calibration but want to use a passive probe enter the attenuation factor by pressing 4Channel5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN external scale NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Attenuation You can use the probe calibration to calibrate any network including probes or cable assemblies The instrument calibrates the voltage at...

Page 84: ...CalibrationOverview ...

Page 85: ...5 Eye Mask and Eyeline Mode Measurement Tutorials ...

Page 86: ... Q factor Rise time and Fall time Mask Measurements The eye may be measured against a number of standard masks One example is used in this tutorial The eye is measured with the mask in place and then a margin measurement is made Eyeline Measurements This section includes a description of the HP Eyeline software and its installation and usage when used with the HP 83480 series digital communication...

Page 87: ...ded display mode see the 4Display5 key in the menus section of this manual for more information Color grade mode must be activated whenever an eye measurement is made After completing this tutorial you will be able to make the following eye measurements of your transmitter s data waveform Extinction ratio HP 83480A only or HP 54750A with optional 83480K upgrade Eye height Crossing percentage Eye w...

Page 88: ...e measurement system according to Figure 5 1 For this particular set of measurements we are testing a laser source using an HP 83485A plug in module with an integrated optical to electrical converter Measurements are also available when measuring electrical signals Figure5 1 Settingupyourmeasurement system 5 4 ...

Page 89: ... be properly positioned on the instrument display The measurement algorithm needs at least two full crossing points on screen to be able to make the measurements You should also have about four divisions of vertical scale Refer to Figure 5 2 Figure5 2 Positionof datawaveform To accomplish this you need to set the trigger vertical scale and the time base 5 5 ...

Page 90: ...he middle of its range See the following note NOTE Typically the trigger level of the instrument is set to a value midway between the high and low levels of the clock or trigger signal connected to the trigger port on the plug in module If the trigger signal varies between 01 volts and 0 volts the trigger level would be set to 00 5 V The trigger can be set to activate on either the rising or falli...

Page 91: ...ing the arrow keys located next to the knob Selecting NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Channel autoscale will generally give you the same results Selecting thetimebase 6 To select the time base press 4Time base5 NNNNNNNNNNNNNNNNN Units bit period HP 83480A only 7 Select the bit rate of your transmitter For this example select 2 48832 GHz STM16 OC48 NNNNNNNNNNNNNNNNNNNNNNNNNN B...

Page 92: ... bit period and entering the bit rate the time base can then be set to show a speci c number of bits For instance if a transmitter is operating at 2 48832 Gbit sec select the STM16 OC48 setting for the bit period To display two complete eyes of the pattern the scale is then set to two bits If the position of the bit pattern needs to be o set by one half bit the current position value is adjusted b...

Page 93: ...NNNNNNNNNNNNNNN Meas Eye A column of softkeys on the right side of the instrument s screen titled Measure eye is displayed N OTE Eye parametric measurements are made from histogram analysis of the instrument s database rather than directly on the active channel To make these measurements the color grade display mode must be turned on When selecting a measurement from the NNNNNNNNNNNNNNNNNNNNNNNNNN...

Page 94: ...libration is performed data for the database will begin to acquire Some of the data will be measured points acquired while the laser is still o therefore the laser should be turned on allowed to stabilize and then the instrument s display should be cleared to have a valid database The extinction ratio measurement is de ned using the measurement database as the mean high level over a windowed porti...

Page 95: ...NNNNNNNNNNNNNNNNN Dark Cal from the softkey menus and follow the instructions displayed on the screen a Turn o the laser and select NNNNNNNNNNNNNNNNNNNNNNNNNN Continue from the softkey menu This establishes a basis for the o set level of the instrument so that a true extinction ratio measurement may be made N OTE The dark calibration requires that the signal level with the laser o be on screen b T...

Page 96: ...e format that you wish your measurement to be displayed by pressing the NNNNNNNNNNNNNNNNNNNN format softkey to cycle among ratio decibel and 4 Select NNNNNNNNNNNNNNNNN Enter from the softkey menus and your measurement will be displayed on the lower left corner of the instrument display 5 12 ...

Page 97: ...high level and low level Eye height is de ned as Eye height Vtop 0 3 top 0 Vbase 3 base These measurements are made over the middle 20 of the eye by default The measurement window can be changed by use of the 4De ne meas5 menu Figure5 4 Eyeheight measurement 1 Select NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Eye height from the softkey menu on the instrument display and the measurement will be displayed in...

Page 98: ...axis This is then used with the mean high and low levels as follows Crossing percent 100 Vcross 0Vbase Vtop 0 Vbase These measurements are made over the middle 20 of the eye by default The measurement window can be changed by use of the 4De ne meas5 menu Figure5 5 Crossingpercentagemeasurement 1 Select NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Crossing from the softkey menu on the instrument display The me...

Page 99: ...crossing points Tcross1 Tcross2 and horizontal standard deviation are determined The Eye width is determined as Eye width Tcross2 03 cross 0 Tcross1 3 cross Figure5 6 Eyewidthmeasurement 1 Select NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Eye width from the softkey menu on the instrument display The measurement will be displayed in the lower left corner of the instrument display 5 15 ...

Page 100: ...ns 63 standard deviations Jitter RMS 1 crossing Jitter p 0 p 6 crossing Figure5 7 Jittermeasurement 1 Select NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Jitter from the softkey menu on the instrument display 2 Select the format that you wish your measurement to be displayed by selecting either NNNNNNNNNNNNNNNNNNNN Format RMS or and NNNNNNNNNNNNNNNNNNNN Format p p 3 Select NNNNNNNNNNNNNNNNN Enter from the softke...

Page 101: ...n the 4De ne meas5 menu Narrow horizontal histograms are computed at the center threshold level to determine the mean location of the rising and falling edge at that level The time di erence between the falling and rising edge can be expressed in absolute time DCD time jTrise center 0Tfall centerj The time di erence between the falling and rising edge expressed as a percentage of the bit period DC...

Page 102: ...om the softkey menu on the instrument display 2 Select the format that you wish your measurement to be displayed by selecting either NNNNNNNNNNNNNNNNNNNN Format time or NNNNNNNNNNNNNNNNNNNN Format 3 Select NNNNNNNNNNNNNNNNN Enter from the softkey menus Your measurement will be displayed on the lower left corner of the instrument display 5 18 ...

Page 103: ... the noise present on the eye The measurement data used is similar to that discussed for eye height Q 0 factor Ptop 0 Pbase top base N OTE The measured values of top and base will include the HP 83480A channel noise Channel noise may be larger than the signal noise resulting in a Q factor less than the theoretical value For typical channel noise gures refer to the documentation for the speci c mod...

Page 104: ...als MakingEye DiagramMeasurements Figure5 9 Q factormeasurement 1 Select NNNNNNNNNNNNNNNNNNNNNNNNNN Q factor from the softkey menu on the instrument display The measurement will be displayed in the lower left corner of the instrument display 5 20 ...

Page 105: ...ed by the following time at the upper threshold crossing 0 time at the lower threshold crossing Rise time The instrument has two standard and a user de ned threshold level for which rise time may be measured The rst is the 10 to the 90 point on the transition and the second is the 20 to the 80 point on the transition The 20 to 80 transition is recommended for devices with signi cant pulse distorti...

Page 106: ...NNNNNNN Bandwidth wavelength NNNNNNNNNNNNNNNNNNNN Filter o 3 Make sure that color grade is on Select 4Display5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Color grade on 4 Select the blue colored button from the ENTRY MEASURE group on the instrument s front panel This activates the Blue Labeled measurement functions of the instrument 5 Select the 4Rise5 button from the ENTRY MEASURE group on the ...

Page 107: ...ined by the following time at the lower threshold crossing 0 time at the upper threshold crossing Fall time The instrument has two standard and a user de ned threshold level for which fall time may be measured The rst is the 10 to the 90 point on the transition and the second is the 20 to the 80 point on the transition The 20 to 80 transition is recommended for devices with signi cant pulse distor...

Page 108: ...hat color grade is on Select 4Display5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Color grade on 4 Select the blue colored button from the ENTRY MEASURE group on the instrument s front panel This activates the Blue Labeled measurement functions of the instrument 5 Select the 4Fall5 button from the ENTRY MEASURE group on the instrument s front panel a Select NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN co...

Page 109: ...testing is used with eye diagrams to de ne the required opening or center of the eye as well as the unacceptable region above the logic 1 level and below the logic 0 level Both the HP 54750A and HP 83480A can test waveforms against user de ned custom masks created and stored using a built in mask editor refer to the Mask Menu section located in Chapter 6 In addition a variety of industry standard ...

Page 110: ... 000 Mb s xed voltage DS4 139 264 Mb s STM1 OC3 155 520 Mb s FC266 265 625 Mb s OC9 466 560 Mb s FC531 531 250 Mb s STM4 OC12 622 080 Mb s OC18 933 120 Mb s FC1063 1 06250 Gb s OC24 1 24416 Gb s GIGABIT ETHERNET 1 2500 Gb s OC36 1 86624 Gb s STM16 OC48 2 48832 Gb s OC192 9 95328 Gb s NOTE The four PDH masks listed above are xed voltage masks Industry standards for these masks require the signal be...

Page 111: ...bit sequence Refer to the appropriate standards for additional information Setting up the system Set up your measurement system according to the following diagram For this particular set of measurements we are testing a laser source using an HP 83485A plug in module with an integrated optical to electrical converter Figure5 12 Setting upthemeasurement 5 27 ...

Page 112: ...rement by automatically adjusting the vertical and horizontal scales The horizontal scale is set to show slightly over one bit period as de ned by the selected mask centered on the screen while the amplitude is set so that the eye covers approximately four vertical divisions In this mode it is not necessary that a full eye initially be displayed because the instrument automatically makes the appro...

Page 113: ...r more information on triggering see the 4Trigger5 menu in this manual located in Chapter 6 Setting thevertical scale mask to waveform mode only 1 Select 4Channel5 from the SETUP group on the front panel of the plug in module where you have input your signal 2 Turn on the channel by selecting NNNNNNNNNNNNNNNNNNNNNNN Display on Ensure all other channels are o 3 If an optical transmitter compliance ...

Page 114: ...he knob 5 Center your waveform on the instrument display Select the NNNNNNNNNNNNNNNNNNNNNNNNNN Position softkey and adjust the display with the arrow keys keypad or the knob NOTE HP 83480A only The instrument has the capability to set its horizontal scale in time units as is typical with conventional oscilloscopes or in a scale corresponding to bit periods By selecting bit period and entering the ...

Page 115: ...RY MEASURE group on the instrument s front panel This activates the Blue Labeled measurement functions of the instrument 2 Select the 4Mask test5 button from the SETUP group on the instrument s front panel You should see a column of softkeys on the right side of the instrument s display titled Mask test N OTE The database is an in nite persistence record of all data since the last time the display...

Page 116: ...ye Mask and Eyeline Mode Measurement Tutorials Testing toaMask Standard Mask HP 83480A only The following gure shows an eye diagram with the standard STM16 OC48 mask applied Figure5 14 Eye withamask 5 32 ...

Page 117: ...y menu b Press NNNNNNNNNNNNNNNNN Enter 4 Select NNNNNNNNNNNNNN Done on the Standard Mask menu 5 Select NNNNNNNNNNNNNN Test on from the Mask Test softkey menu When mask test is turned on testing will begin The database will be cleared and reset whenever 4Clear display5 is pressed or when the horizontal or vertical scales are changed 6 Select NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Mask align on the Mask T...

Page 118: ...ber of failed samples that have violated the lower number 3 region of the mask Usingmaskmargins When a test device passes a mask test without any violations it is often useful to determine the margin of compliance Mask margins are used for this purpose First a mask measurement is made then the mask is linearly increased in size by a particular percentage For instance if you want to verify that the...

Page 119: ... size of the margin For this example the margin is 20 larger than the mask total hits This is the total number of failures margin hits This is the number of failures due to the margin All data acquired since mask testing was enabled will be compared to the margin Sampled points acquired before the margin was activated that fall into the margin region will also show up as mask hits mask hits This i...

Page 120: ...aligned turn the mask test on 2 Acquire the desired number of samples and or waveforms that result in an accurate representation of the test device performance 3 Stop the instrument from acquiring data Press 4Stop Single5 4 Increase the mask margin value until the monitored test data indicates mask violations 5 The largest margin value where no mask violations occur yields the device margin 5 36 ...

Page 121: ...e HP 83480 series digital communications analyzer The bene ts achieved by using HP Eyeline software are continuous traces to show individual waveforms that make up an eye diagram referred to as eyeline traces noise reduction in eye diagrams through trace averaging analysis of speci c data patterns that lead to mask violations referred to as error trace capture 5 37 ...

Page 122: ...ram as a con guration of sampled data points While these data points accurately represent a digital data signal there is essentially no way to view the individual waveforms or bit sequences that make up an eye pattern Through sequential sampling point by point through a repetitive data pattern individual traces can be displayed Figure5 16 Conventional eyediagramdisplay 5 38 ...

Page 123: ...71604B 70841B 71612A or 70843A One data point is taken for each valid trigger The entire data pattern is transmitted from the pattern generator before the next trigger Through control of the position of the trigger relative to the data pattern a continuous or eyeline trace can be produced However because only one data point is measured for each repetition of a data pattern a waveform takes longer ...

Page 124: ... Trace averaging is not a viable noise reduction technique for multi valued waveforms such as an eye diagram because the result is the average between the two logic levels which results in a collapsed eye Because eyeline mode produces continuous traces trace averaging can be used for noise reduction When averaging is implemented each eyeline trace is measured N times N averages and the average of ...

Page 125: ...Eye Mask and Eyeline Mode Measurement Tutorials MakingEyeline Measurements HP83480A Option001only Figure5 19 Low powersignalviewedwith eyelinemodeusingaveraging 5 41 ...

Page 126: ...apture Mask testing is a standard feature of the HP 83480 series digital communications analyzer In addition to determining when mask violations occur the eyeline application allows determination of the bit sequence that led to a mask violation Figure 5 20 Maskviolationand thesequenceleadingto theviolation 5 42 ...

Page 127: ...connected to the trigger input on the instrument Avoid excessive signal levels On the HP 83480A select NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN DC 2 5 GHz triggering bandwidth when using eyeline mode Eyeline mode is not compatible with NNNNNNNNNNNNNNNNNNNNNNNNNN 2 12 GHz or NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN 2 12 GHz Gate triggering Figure5 21 Front panelconnectionforeyeline mode The HP IB cable sh...

Page 128: ...IG menu and correct the address The program starts when the pattern generator address is set properly NOTE When the eyeline program is running almost all front panel access is retained even though the instrument is in remote Front panel keystrokes are detected over HP IB and passed back to the instrument over HP IB This slows down the front panel interface especially the knob so you have to be mor...

Page 129: ...ing 4STOP5 The pattern generator returns to local so you can now change pattern length bit rate and so forth When you have nished making these adjustments resume operation of the eyeline program by pressing 4RUN5 To exit the program completely without unloading it from memory press 4Shift5 4Local5 You can now use the knob and front panel keys at normal speed Note that when using 4Local5 you don t ...

Page 130: ... measurement such as extinction ratio without rst turning on color grading the instrument asks if you want to turn color grading on A menu with two keys NNNNNNNNNNNNNNNNNNNNNNNNNN CONTINUE and NNNNNNNNNNNNNNNNNNNN CANCEL is displayed When you are running the eyeline program these functions are not active To get out of this state without cycling power press 4Shift5 4Local5 NNNNNNNNNNNNNNNNNNNNNNNNN...

Page 131: ...iagram and gives the user complete control of the pattern generator 2 The eyeline mode puts the pattern generator in remote and executes the line mode operation N OTE Measurement rate is strongly in uenced by data pattern type and length Instrument throughput in eyeline mode is dominated by the rate at which valid triggers are generated by the pattern generator This is a function of the data rate ...

Page 132: ...sure that the desired number of bits is displayed in the sequence leading to a mask violation Set the time base position to several bits or time increment above the lowest allowable value to ensure the full sequence is seen For example the minimum setting at 622 Mbit sec is 13 7 bits To view 10 bits set the position to greater than 24 bits Similarly at 2 488 Mbit sec the minimum setting is 54 7 bi...

Page 133: ...ion001only An appropriate formula for adjusting the mask to the right screen edge is to adjust the time base position as follows new position old position 0 timebase scale in bits 0 2 bits Figure5 23 Display afterinitialmaskalignment Figure5 24 Displayaftertimebase positionadjustment 5 49 ...

Page 134: ...creen and any waveform violations show up on the bottom screen The mask extends vertically across the entire screen but this does not cause a problem The analyzer continues to measure waveforms until a mask violation occurs Standard masks custom masks or mask margins can generate violations When a violation occurs the trace leading to the violation is displayed This trace will be updated when subs...

Page 135: ...t recent error trace To restart an Error Trace Capture display press NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN START CLEAR ERROR TRACE CAPTURE Do not use 4CLEAR DISPLAY5 because it does not clear the waveform memory To return the instrument to a single display with no error trace displayed press NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN...

Page 136: ...Eye Mask andEyelineModeMeasurement Tutorials ...

Page 137: ...6 The Digital Communications Analysis Menus ...

Page 138: ...The Digital Communications Analysis Menus Whatyou ll ndin thischapter This chapter describes the Mask Test menu the Measure Eye menu the Channel Setup menu the Time Base menu and the Trigger menu 6 2 ...

Page 139: ...ortions of the mask can be increased or decreased in a linear fashion to determine the waveform s margin of compliance Both the user de ned and standard factory installed masks can be stored to disk for rapid switching between instrument setups In rmware revision A 02 00 and above ve mask memories are available internal to the instrument to permit custom masks to be stored without the need for a o...

Page 140: ...voltage masks This means the test signal 1 and 0 voltages must fall within certain absolute limits and the mask is not permitted to scale vertically to t the waveform In rmware A 02 00 and above the HP 83480A automatically performs xed voltage mask tests on these rates There are two considerations in mask testing at these rates the mask is speci ed for a 75 ohm test impedance and the required sign...

Page 141: ...asks These masks may be created using one of two methods by using the Edit Mask menu to create a new or modify an existing mask or by using the Auto Mask menu to create a mask from a waveform The rst method involves constructing polygons while the second method involves the use of a reference waveform Using the rst method polygons are created to mask o failure regions of the graticule Up to eight ...

Page 142: ...base operates independently of the waveform record for each channel When any one of these three features are activated the instrument begins to build the database The database is the size of the graticule area 256 pixels high by 451 pixels wide Behind each pixel is a 16 bit counter When color graded display mask testing or histograms are activated a database is built by incrementing the 16 bit cou...

Page 143: ... When the Test function is on the database begins building if color grade and histograms are not already active and the data is compared to the current mask When the Test function is o the data is not compared to the mask KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNN Test on or o NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Create mask The Create Mask function activates menus that allow the use of in...

Page 144: ...e settings Current is typically in volts and seconds or other appropriate units for the source KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Create mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Automask NNNNNNNNNNNNNNNNN Units NNNNNNNN 1X The 1X function de nes the horizontal tolerance around the edges of the reference waveform The 1X value de nes the tolerance around edges K...

Page 145: ... OC12 STS3 Eye OC24 STS3 Pulse 0 STM16 OC48 STS3 Pulse 1 FC133 DS1 FC266 DS1C FC531 DS2 FC1063 DS3 FDDI PDH 2 048 Mb 100BASE FX PDH 8 448 Mb GIGABIT ETHERNET PDH 34 4 Mb PDH 139 Mb 0 PDH 139 Mb 1 Use the RPG knob or the arrow keys to highlight the desired mask and press NNNNNNNNNNNNNNNNN Enter to select the mask KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Create mask N...

Page 146: ...ot operate correctly with the edited mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Procedure to NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN define a mask The Procedure To De ne a Mask function brings up a set of brief instructions on how to construct a mask KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Create mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Edit Mask NNNNNNNNNNNN...

Page 147: ...mediate values of mask margins KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Create mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Edit Mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNN polygon NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Edit polygon The Edit Polygon function gives you access to a second level menu that allows you to either edit or construct a polygon Before entering ...

Page 148: ...re6 1 Legal andillegalpolygonconstruction KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Create mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Edit Mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Edit polygon NNNNNNNNNNNNNNNNN Point NNNNN X The X function moves the cursor horizontally across the display allowing you to de ne a point KeyPath 4Shift5 4Mask test5 NNNNNNNNN...

Page 149: ...tkeys KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Create mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Edit Mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Edit polygon NNNNNNNNNNNNNN Move NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Delete polygon The Delete Polygon function deletes the selected polygon KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN...

Page 150: ...ected polygon number appears on the display next to the rst point 4 Repeat the procedure to place the second point The scope draws a line from the rst point to the second point and the NNNNNNNNNNNNNNNNN Point softkey increments to the number 2 5 Continue adding points up to a maximum of 512 points 6 Use the NNNNNNNNNNNNNNNNNNNN Delete softkey to remove a point or use the NNNNNNNNNNNNNN Move softke...

Page 151: ...lygon in Figure 6 2 looks like both points are o the screen However rescaling the polygon by changing the NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Y2 Position value from 1 mW to 500 W shrinks the polygon in Figure 6 3 You may notice that the top left point stayed xed to the top of the screen while the top right point moved into the graticule area To keep a point xed to a side of the graticule area set ...

Page 152: ... 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Create mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Edit Mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNN polygon NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Edit polygon NNNNNNNNNNNNNNNNN Point Use the knob or keypad to select the point on the polygon you wish to edit The analyzer will not select an unde ned point 3 To delete the selected poi...

Page 153: ...ask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Create mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Save recall NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Mask margins Once a mask has been selected or created a margin can be added to the masks for tolerance testing A masks margin is a linear expansion of all the polygons that make up a mask in terms of the 0 margin mask and the 100 margin ...

Page 154: ...ent method to determine waveform margin The mask margin can be turned on with an initial value of 0 Using the RPG or arrow keys the margin value can be increased while monitoring the margin hits When the number of hits increases from 0 to some speci c level the margin is determined Range is 0100 to 100 percent KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Create mask NNN...

Page 155: ...sions apart If the source is set to 50 mV div the markers will be about two divisions apart With a channel as the source the scaling of the X1 and 1X markers is set by the time div setting in the Time Base menu With a function or memory as the source the scaling can be independent of the time base Also the 0 level 1 level X1 position and 1X lines show upon the display as a solid line in the Scale ...

Page 156: ...e Y2 Position softkey KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Scale mask NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN 1 level Y2 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN 0 level Y1 The Y1 Position function de nes the horizontal line where Y 0 The Y1 marker tracks the Y1 Position softkey This control is typically set to the value that corresponds to a logical 0 To change between ECL to...

Page 157: ... used to determine where the mask is placed acts on all the data currently in the database If the display is set to variable persistence the alignment of the mask can be a ected by data that is in the database but not displayed N OTE To ensure all of the data in the database is displayed mask testing should be performed in In nite Persistence mode To ensure proper mask alignment set the time base ...

Page 158: ...he alignment KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Align mode NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Mask to wfrm NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Fill Display Available with rmware A 02 00 and higher The Fill Display function optimizes the measurement by automatically adjusting the vertical and horizontal scales The horizontal scale is set to show slightly over one bi...

Page 159: ...run continually and not to stop after a xed number of failures or acquisitions For example you may want the mask test to run overnight and not be limited by a number of failures or acquisitions KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNN Run NNNNNNNNNNNNNNNNNNNNNNN forever NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Failed wfms The Failed Waveforms function runs the mask test until a set number of fa...

Page 160: ...hat allows you to set the number of waveforms KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNN Run NNNNNNNNNNNNNNNNNNNNNNNNNNNNN waveforms NNNNNNNNNNNNNNNNNNNNNNN Samples The Samples function runs the mask test until a set number of samples are acquired When samples is selected another softkey is displayed that allows you to set the number of samples KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNN...

Page 161: ...NNNNNNNNNNNNNNNNNNNNNNN Enable failure NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Store summary The summary is a log of the mask test data from failed test results There are two parts to the summary The rst part is a header that is a running total of the number of failures The second part is the log of the results on each failure When a failure does not occur during a set of measurements t...

Page 162: ... Disk function stores the summary information to a disk The Store Summary menu allows you to specify the rst four characters of the le name The last four characters are reserved for consecutively numbering any subsequent summary les stored to the disk If you select SUMM as the rst four characters of the le name the le name of the summary le stored to the disk is MSUM0000 SUM The le name of the sec...

Page 163: ...rea The choices are o pixel memory printer disk The screen image allows you to see what the display looked like at the time of the failure but you cannot rescale it later like you can with waveform memories or functions If the Help menu is displayed on the screen at the time of the failure then the Help menu is the screen image that is stored KeyPath 4Shift5 4Mask test5 NNNNNNNNNNNNNNNNNNNNNNNNNNN...

Page 164: ...ore summary in this chapter applies except that the le extension depends on the selected print format For example the ThinkJet selection has a PCL extension and the TIFF selection has a TIF extension NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Store wforms The Store Wforms function sends a copy of a channel function or memory to the selected destination of o memory or disk Waveform is not an i...

Page 165: ...NNNNNNNNNNNNNNNNNNNNNNNNNNN Fail action NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Store wforms NNNNNNNNNNN off NNNNNNNNNNNNNNNNNNNN Memory The Memory function stores a copy of what the Source softkey is set to to one of the four waveform memories the same waveform memories that are accessed by the Waveform menu Because a waveform memory can contain only one waveform at a time a waveform memory is bes...

Page 166: ...or This function is only available with the HP 83480A or if the HP 83480K option is installed in an HP 54750A NOTE If this is the rst time you are using the instrument to make any or all of the eye measurements refer to the tutorials in Chapter 5 The tutorial includes all the procedures required to perform the measurements measurement examples and a basic discussion on measurement results and how ...

Page 167: ...d in this section or those described in Chapter 8 Eye measurements are performed only on a color graded database When one of the seven measurements located in the Measure Eye menu is selected the color graded database will be activated automatically if it has not already been enabled N OTE The accuracy of eye measurements depends on the amount of data in the color graded database For the rst few s...

Page 168: ...n turn can be signi cantly a ected by any noise generated by the measurement system such as O E converter DC o sets or electrical o sets in the instrument electronics Thus the extinction ratio measurement is de ned as Vtop 0Vdark Vbase 0Vdark Vtop or Ptop and Vbase or Pbase are determined from vertical histograms of the eye window The eye window is the center of the eye and is de ned in the De ne ...

Page 169: ...you are instructed to turn o the transmitter The instrument can then characterize any internal noise signals present and remove them during the extinction ratio calculations N OTE The dark cal routine varies slightly depending on the calibration status of the instrument Whenever the channel o set calibration is invalid the dark cal routine automatically invokes the o set cal routine for optical ch...

Page 170: ...NNNNNNN Extinction ratio NNNNNNNNNNNNNNNNNNNNNNNNNN Dark cal Extinction ratio can be displayed in one of three formats dB ratio The desired format is selected in the Extinction Ratio menu KeyPath 4Shift5 4Meas eye5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Extinction ratio NNNNNNNNNNNNNNNNNNNN Format ratio decibel or The ratio format calculates extinction ratio as ratio Vtop 0 Vd...

Page 171: ... ratio measurement a vertical histogram is calculated for data falling within the de ned window determined in the De ne Measure menu VTOP and the high levels distribution are determined Similar patterns are determined for the low levels The eye height is determined as Eye height Vtop 0 3 top 0 Vbase 3 base Figure6 6 Eyeheight measurement KeyPath 4Shift5 4Meas eye5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN ...

Page 172: ...ntage would be 50 according to the following formula Crossing percent 100 Vcross 0Vbase Vtop 0 Vbase Vtop and Vbase are calculated from a histogram using data within the eye window as de ned in the De ne Measure menu Vcross is the most prevalent vertical location or amplitude of the crossing points A horizontal histogram over the entire display is used to determine the time location of the crossin...

Page 173: ...The Digital Communications Analysis Menus MeasureEyeMenu Figure6 7 Crossing measurement 6 37 ...

Page 174: ...e color grade database to determine the mean location of the crossing points as well as the statistical distribution of the crossing points As would be expected noise and jitter will cause a large variance in the location of the crossing points and result in the closure of the eye Eye width Tcross2 0 3 cross2 0 Tcross1 3 cross1 KeyPath 4Shift5 4Meas eye5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Eye width Fig...

Page 175: ...he crossing points An iterative process is used to narrow the histogram window to precisely determine the crossing points and the variance Jitter can be displayed in one of two formats peak to peak or RMS Both values are based on the standard deviation of the crossing point position Jitter RMS 1 crossing Jitter p p 6 crossing Figure6 9 Jitter measurement KeyPath 4Shift5 4Meas eye5 NNNNNNNNNNNNNNNN...

Page 176: ...s 50 Duty cycle distortion is measured by histogram analysis at the crossing points and middle threshold Duty cycle distortion can be displayed in two formats time or percent In the time format the actual time between the median falling edge and the median rising edge at the middle threshold is determined In the percentage format the time di erence is determined as a percentage of the full bit wid...

Page 177: ...imilar to the extinction ratio and eye height measurements The most prevalent Ptop and Pbase as well as the data distribution indicative of noise present is calculated from the histogram Data is collected over the eye window de ned in the De ne Measure menu Q 0factor Ptop 0 Pbase top base N OTE The measured values of top and base will include the HP 83480A channel noise Channel noise may be larger...

Page 178: ...The Digital Communications Analysis Menus MeasureEye Menu Figure6 11 MeasuringQ factor 6 42 ...

Page 179: ...hannel Setup menu is accessed from the front panel Channel key of the appropriate plug in module There is a separate key for each channel Modules with two channels have two keys modules with one channel have one key Most menu functions only operate on the selected channel Some softkeys such as Cal Status access functions that apply to the entire module These functions can be accessed from either C...

Page 180: ...e Base Menu This section contains a description of the Time Base menu and how it controls the horizontal portion of the display The topics covered are horizontal scale position reference and windowing 6 44 ...

Page 181: ...ftkey later in this chapter KeyPath 4Time Base5 NNNNNNNNNNNNNNNNN Units time or bit period aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Bit Rate This function is only available with the HP 83480A or if the HP 83480K option is installed in an HP 54750A Bit rate allows the time base to be con gured for a variety of standard optical and electrical telecommunications rates In the Bit Rate mode the knob a...

Page 182: ...n the instrument is stopped and you expand the scale the instrument redisplays the signal at the new scale setting This feature allows you to zoom in or to zoom out on the signal If you watch the memory bar at the top of the display you can see what portion of memory you are zooming on KeyPath 4Time Base5 NNNNNNNNNNNNNNNNN Scale aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Position The Position funct...

Page 183: ...osition to the center of the display The reference also de nes the expansion point for the time base scale control When Center is selected the data is acquired evenly on both sides of the reference point The data in the waveform record is centered around the reference point and changing the scale expands or contracts the signal about the center of the display When Left is selected the data is acqu...

Page 184: ... and position settings and a window marker is placed on the signal The window marker de nes the portion of the signal you plan to expand However the color highlight is not available when mask testing is turned on The default color of the window marker is red but you can change the window marker color in the Display menu The Window function expands and displays the portion of the signal that is out...

Page 185: ...function moves the intensi ed marker horizontally across the main sweep It allows you to pick the segment of the main sweep you wish to expand for further analysis KeyPath 4Time base5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Time base windowing on NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Window position 6 49 ...

Page 186: ...he same time as a sample point Because the instrument knows when the trigger event happened in relation to the sampled data the instrument knows where to place the sampled data on the display There are three green LEDs at the top left corner of the mainframe When a LED is lit it indicates the trigger status of the instrument Armed The instrument is waiting for a trigger event to occur Triggered Th...

Page 187: ...nstrument is forced to trigger when armed giving you glimpses of the signal which then allows you to set up channel vertical scales to display signals KeyPath 4Trigger5 NNNNNNNNNNNNNNNNN Sweep triggered or free run aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Source The Source function displays a list of the available trigger sources The list of available trigger sources depends on the combination of plug ins ...

Page 188: ...or ratio aaaaaaaaaaaaaaaaaaaaaaaaaa Level Level speci es the voltage threshold that a signal must cross in order for the instrument to trigger on that signal You can use the knob arrow keys or keypad to change the trigger level You can adjust the trigger level from within any of the trigger submenus KeyPath 4Trigger5 NNNNNNNNNNNNNNNNN Level aaaaaaaaaaaaaaaaaaaaaaaaaa Slope Slope speci es whether t...

Page 189: ...NNNNNNNNNNNNNNNNNNNNNNNNNNNN DC 2 5 GHz The DC 2 5 GHz function provides direct triggering on 2 5 GHz signals KeyPath 4Trigger5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Trig Bandwidth NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN DC 2 5 GHz NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN DC 100 MHz The DC 100 MHz function limits the trigger bandwidth by applying a low pass lter KeyPath 4Trigger5 NNNNNNNNNNNNNNNNNNNNNNNNN...

Page 190: ...al to extend triggering capability This trigger bandwidth mode can not be used when the HP 83480A is performing eyeline measurements Use the NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN DC 2 5 GHz mode instead This function is available on the HP 83480A Option 100 only Refer to 2 12 GHz mode Option 100 only in Chapter 13 for additional information KeyPath 4Trigger5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN...

Page 191: ...7 Waveform Measurements ...

Page 192: ...bes the process the instrument uses to make general waveform measurements It also describes the parameters that are measured and how to set up measurements for the best solution Chapter 6 discusses how the instrument characterizes a variety of eye diagram parameters 7 2 ...

Page 193: ...ows the pulse parameters the instrument measures Hewlett Packard has been using these IEEE parameters in its measurements for over ten years This chapter de nes these parameters and discusses how they are measured Figure7 1 Pulseparameters theinstrumentmeasures 7 3 ...

Page 194: ... level is present in the data record A q level is an internal voltage representation From the histogram and from the data record the absolute maximum and minimum power or voltage levels as well as relative maximum top and minimum base power or voltage levels are determined A horizontal time histogram is constructed to determine crossing points for eye diagrams Using the top and base levels thresho...

Page 195: ...rument must rst collect data about that signal In the case of a live signal being measured from the front panel the measurement process begins as soon as any data is available The data record used for making measurements on waveform memories is the stored data Measurements being made on functions require that the function be calculated before the measurement process is started 7 5 ...

Page 196: ...istribution of the internal voltage levels as shown in Figure 7 3 The histogram does not represent the full resolution of the data however as this would result in a very large histogram array The instrument uses the histogram to determine the statistical maximum top and minimum base of the data record Figure7 3 Some measurementsaremadefrom thehistogram 7 6 ...

Page 197: ...rd As it represents the full resolution of the signal the absolute maximum and minimum voltage levels are determined from the data record If the waveform is clipped this information is also recorded After the minimum and maximum measurements are complete the Vmin Vmax Vp p Tmin Tmax and Tvolt measurements can be made The remaining primitives of the measurement process calculate thresholds nd edge ...

Page 198: ...the occurrence count is less than a predetermined statistically signi cant value the top defaults to the value of the absolute maximum Likewise the base represents the level with the greatest number of occurrences in the bottom portion of the histogram If the occurrence count is less than a statistically signi cant value the base defaults to the value of the absolute minimum This may be the case f...

Page 199: ...k regions top and base default to the absolute maximum and minimum Once the top and base measurements are complete Vtop Vbase and Vamp measurements can be made Locating crossing points When eye diagrams are measured the crossing points are determined Data within the top and base levels are used to construct histograms from which approximate crossing points can be determined An iterative process is...

Page 200: ...lds are called upper middle and lower thresholds in the Measurement menu These thresholds are used by all timing measurements as they are needed to determine the presence of a rising or falling edge In addition the thresholds are used by various measurements For example rise time is measured from the lower threshold to the upper threshold of a rising edge Period and frequency measurements use the ...

Page 201: ...nd upper threshold levels A falling edge is de ned as a transition that passes through the upper middle and lower threshold levels For an edge to be present and de ned it must complete the transition through all three threshold levels Once the transition points and edges are identi ed the instrument next calculates timing measurements rise time fall time and frequency Finally it calculates voltage...

Page 202: ...oints about the threshold Then the location of the transition point is recorded in an edge array The system ignores incomplete transitions and glitches as shown in Figure 7 7 Figure7 7 Thesystem ignoresincompletetransitionswhen de ningedges The instrument de nes the points on a rising edge as the last point before crossing the lower threshold to the rst point crossing the upper threshold The point...

Page 203: ...last point through the upper threshold gives a di erent answer than the shaded line that uses the edge de nition given in the previous paragraph The points in a period are de ned to be the midpoint between the rst point before crossing the middle threshold to the last point after crossing the middle threshold Figure7 8 Waveformperiod ismeasuredatthe middlethreshold 7 13 ...

Page 204: ...results Voltage and power measurements Once the top and base calculations area completed most of the voltage or optical power measurements can be made Vmin Vmin voltage or power of the absolute minimum level Vmax Vmax voltage or power of the absolute maximum level Vp p Vp p Vmax 0 Vmin or Pmax 0 Pmin Vbase Vbase voltage or power of the statistical minimum level Vtop Vtop voltage or power of the st...

Page 205: ... waveforms Figure 7 9 shows where these waveform de nitions occur Figure7 9 Waveformde nitions usedtomakevoltage measurements Several of the voltage measurements require threshold and edge information before they can be made Vavgcycle Vavg cycle average voltage of the rst cycle of the signal Vavg Vavg average voltage of all data on the display dc Vrms dc Vrms q v2 t n ac Vrms ac Vrms p v t 0V avg ...

Page 206: ...ng preshoot base 0 local min Else preshoot local max 0 top The instrument computes a local minimum and maximum when computing preshoot and overshoot The local minimum or maximum occurs before the rst transition in the case of preshoot or in the rst 50 percent of the time de ned along the threshold in the case of overshoot This makes windowing less critical for these measurements NOTE Preshoot dc V...

Page 207: ...er threshold on the rst rising edge Fall time Fall time time at the lower threshold 0 time at the upper threshold on the rst falling edge Period If the rst edge is rising period mid threshold crossing of second rising edge 0 mid threshold crossing of rst rising edge Else period mid threshold crossing of second falling edge 0 mid threshold crossing of rst falling edge For an eye measurement period ...

Page 208: ...e Else Width mid threshold crossing of second falling edge 0 mid threshold crossing of rst rising edge 0Width If rst edge is rising 0Width mid threshold crossing of second rising edge 0 mid threshold crossing of rst falling edge Else 0Width mid threshold crossing of rst rising edge 0 mid threshold crossing of rst falling edge Dutycycle Duty Cycle Width period 100 7 18 ...

Page 209: ...alculated as the time from the rst source s edge to the second source s edge This gives exibility in de ning 1time measurements between channels or on a single channel between edges To avoid confusing the delay measurement with time base delay and trigger delay the delay measurement has been called 1time as shown in Figure 7 10 Refer to Chapter 10 for information on delay measurements Figure 7 10 ...

Page 210: ...n standard deviation min and max for each measurement result In the User De ned mode you may also de ne some of the measurements you want to make You may specify your own thresholds rather than using the standard 10 50 and 90 percent or 20 50 and 80 percent levels specify the IEEE standard de nitions of thresholds and measurements or set thresholds in either voltage or percent You may rely on the ...

Page 211: ...8 Making Automatic Measurements ...

Page 212: ...front panel Measure section General Measure menu Freq Domain menu and Histogram menu The General Measure Frequency Domain and Histogram functions are located in the De ne Measure section of the front panel To access these functions press the blue 4Shift5 key and the desired function 8 2 ...

Page 213: ...ome automatic measurements You will get a warning or error message if this occurs Period and frequency measurements At least one full cycle of the waveform with at least two like edges must be displayed for period and frequency measurements Additionally you can increase the accuracy of frequency measurements by windowing on multiple pulses Automatic waveform measurements use a single pulse and may...

Page 214: ... rising edge preshoot and overshoot measurements The trailing falling edge of the waveform must be displayed for fall time and falling edge preshoot and overshoot measurements Remember that an edge must pass through all three thresholds to be recognized as an edge Therefore it is important that the pulse be positioned so that all three thresholds are displayed on the screen Rise time fall time pre...

Page 215: ...ter 7 Before making signal measurements it is important the instrument is correctly con gured in terms of measurement de nitions versus the signal type to be measured This is typically achieved by using the De ne Measure menu The following information lists the various utilities that are single key measurements That is the measurement has a dedicated key typically a shifted function Several other ...

Page 216: ...aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 0width The time between the falling edge at the middle threshold and the rising edge at the middle threshold KeyPath 4Shift5 NNNNNNNNNNNNNNNNNNNNN 0width aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Duty Cycle The ratio of the width to the period When crossing points of an eye diagram are above the 50 threshold duty cycle can exceed 100 KeyPath 4Shift5 NNNNNN...

Page 217: ...e 4Display5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Color grade on KeyPath 4Shift5 NNNNNNNNNNNNNN fall aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Frequency Frequency is 1 period of the rst detected edge to the next detected edge KeyPath 4Shift5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Frequency aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Overshoot A histogram is used to characterize signal levels above Vtop...

Page 218: ...th 4Shift5 NNNNNNNNNNNNNNNNNNNN period aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Preshoot The deviation from the Vbase signal prior to a rising edge KeyPath 4Shift5 NNNNNNNNNNNNNNNNNNNNNNNNNN Preshoot aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Rise Time Threshold levels 20 to 80 10 to 90 or user de ned are set in the De ne Measure menu The 20 to 80 thresholds are recommended for eye diagram ana...

Page 219: ...NNNN Vamp aaaaaaaaaaaaaaaaaaaaaaaaaa Vbase Measures the most prevalent value of the lower portion of a pulse or eye diagram for example the mean value of the logical 0 in an eye diagram KeyPath 4Shift5 NNNNNNNNNNNNNNNNN Vbase aaaaaaaaaaaaaaaaa Vpp Measures the separation between the maximum and minimum measured signals KeyPath 4Shift5 NNNNNNNNNNN Vpp 8 9 ...

Page 220: ...ntinuous repetition signal and not eye diagrams It is not available with color graded database KeyPath 4Shift5 NNNNNNNNNNNNNN Vrms aaaaaaaaaaaaaaaaaaaaaa Vtop Measures the most prevalent value of the upper portion of a pulse or eye diagram for example the mean value of the logical 1 of an eye diagram KeyPath 4Shift5 NNNNNNNNNNNNNN Vtop 8 10 ...

Page 221: ...eneral Meas Menu To access the General Meas menu press 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN General Meas The measurements available include Tmax Tmin Vavg Vupper Vmiddle Vlower 8 11 ...

Page 222: ...NNNNNNNNNNNN Tmax aaaaaaaaaaaaaaaaaaaaaa Tmin The time at which the rst Vmin sample occurs For a histogram the minimum extreme of the histogram is returned KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN General Meas NNNNNNNNNNNNNN Tmin aaaaaaaaaaaaaaaaaaaaaa Vavg The average of the entire displayed waveform or a single period selectable KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNN...

Page 223: ...NNNN Vlower aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Vmiddle Marks the level of the middle threshold as de ned in De ne Measure KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN General Meas NNNNNNNNNNNNNNNNNNNN Vupper aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Vupper Marks the level of the upper threshold as de ned in De ne Measure KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN...

Page 224: ...NNNNNNNNNNNNN Avg Power aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Avg Power Yields the average power of an optical signal measured on an optical channel derived directly from the dc component of the photocurrent KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Avg Power 8 14 ...

Page 225: ...eturns the frequency value of a peak in the FFT spectrum as de ned by peak number and peak threshold KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Freq Domain NNNNNNNNNNNNNNNNNNNNNNNNNN FFT freq aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa FFT mag Returns the magnitude value of a peak in the FFT spectrum as de ned by peak number and peak threshold KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNN...

Page 226: ...NNNNNNNNNNNNNNNNNNNNNNNN FFT 1freq aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa FFT 1mag Returns the magnitude di erence between two peaks in the FFT spectrum as de ned by peak numbers KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Freq Domain NNNNNNNNNNNNNNNNNNNNNNNNNN FFT 1mag After an FFT measurement is selected a second level menu allows you to customize the measurement The delta...

Page 227: ...nt For example a peak number of 2 indicates the measurement is made on the second peak from the left side of the screen The delta frequency and delta magnitude measurements have two peak selections The delta magnitude measurement is performed by determining the magnitude of each of the two peaks and then subtracting the magnitude of the rst peak from the magnitude of the second peak The delta freq...

Page 228: ...spectrum must be above the threshold level and must go up and down at least one eighth of full scale one division KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Freq Domain NNNNNNNNNNNNNNNNNNNNNNNNNN FFT Freq or NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN FFT Magnitude or NNNNNNNNNNNNNNNNNNNNNNNNNNNNN FFT 1Freq or NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN FFT 1Magnitude NNNNNNNNN...

Page 229: ...tion to be active in the Histogram menu aaaaaaaaaaaaaaaaaaaaaaa 61 Returns the percentage of the total hits falling within 61 KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Histogram NNNNNNNNNNNNNNN 61 aaaaaaaaaaaaaaaaaaaaaaa 62 Returns the percentage of the total hits falling within 62 KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Histogram NNNNNNNNNNNNNNN 62 8 19 ...

Page 230: ...stogram NNNNNNNNNNNNNNN 63 aaaaaaaaaaaaaaaaaaaaaa hits Returns the number of samples that fall within the displayed histogram window KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Histogram NNNNNNNNNNNNNN hits aaaaaaaaaaaaaaaaaaaaaa mean Returns the most prevalent value of the histogram KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Histogram NNNNNNNNNNNNNN mean 8 20 ...

Page 231: ...NNNNNNNNNNNNNNNN median aaaaaaaaaaaaaaaaaaaaaa peak Returns the number of hits occurring at the most prevalent value of the histogram KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Histogram NNNNNNNNNNNNNN peak aaaaaaaaaaaaaaaaaaaaaaaaaa pk pk Returns the peak to peak range of the histogram KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Histogram NNNNNNNNNNNNNNNNN pk pk 8 21 ...

Page 232: ...tic Measurements aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa std dev Returns the standard deviation of the histogram KeyPath 4Shift5 4More Meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Histogram NNNNNNNNNNNNNNNNNNNNNNN std dev 8 22 ...

Page 233: ...9 Increasing Measurement Accuracy and Time Interval Measurement ...

Page 234: ...ous methods for making time interval measurements and the pros and cons of each The second section introduces the concept of statistical analysis of time intervals The third section explores errors in time interval measurements that are not related to the time base accuracy including the response of the instrument s vertical channels and the e ect of probes This chapter also examines the distortio...

Page 235: ...ruments are similar In all cases you measure the time between two events where an event is de ned as a voltage transition of a speci ed polarity through a speci ed level When measuring the width of a pulse these two events are the leading edge and the trailing edge The concepts developed here can be applied to any other time interval measurement For two channel measurements you must take care to d...

Page 236: ...mine the top and base levels If the baseline is distorted prior to the initial transition of the pulse enough of the true steady state baseline must be present on the screen so that it will be identi ed clearly in a voltage histogram as the most prevalent value The minimum time division setting that achieves this will give the most accurate measurement In other words spread the pulse out to occupy...

Page 237: ...measurement and by using the markers Channel to channel measurements To make channel to channel measurements such as propagation delay setup time or hold time you must remove any systematic di erences in the delays between the two acquisition channels and any associated probes or cables This is accomplished with the Calibrate and Skew keys refer to Chapter 4 in this manual Statistics To con dently...

Page 238: ...u to its minimum value Set the Reference control in the Time Base menu to Center Set up the instrument to view a fast rising edge from a pulse generator such as an HP 8131A The triggered edge should be at the center of the screen Press the Trigger menu key You will see the trigger level marker displayed on the screen Ideally there would be no jitter no horizontal spreading of the trace where the w...

Page 239: ...utomatic measurements in the instrument to measure the jitter and observe its statistics To calculate the slope of the variable jitter subtract the xed jitter from the observed jitter and divide by the Position setting The jitter in the instrument has approximately normal distribution For measuring jitter that also has a normal distribution the standard deviations add in quadrature as shown in equ...

Page 240: ...tical averaging removes the apparent jitter on the display but may give misleading information about the true behavior of the signal For example consider measuring rise time Figure 9 1 shows a rise time measurement on a jittering signal with averaging turned on Figure9 1 Erroneousrise timemeasurementsdueto jitter 9 8 ...

Page 241: ...e can be divided into the following categories dc errors These include o set level error gain error vertical non linearity and vertical resolution limits Dynamic response errors In general the errors from the transient response of the vertical channels and probes are more signi cant than those from dc level errors in the vertical channels especially for fast slewing edges dc errors Time interval m...

Page 242: ...e errors cancel when you measure the time between two edges having the same polarity amplitude o set and slew rate at the same dc level on the same channel Note that this rule applies only to single channel measurements For channel to channel measurements the dc errors on each channel could be di erent so the errors may not cancel If the slew rates of the edges are di erent as in Figure 9 2 there ...

Page 243: ...terval measurements between edges of opposite polarity the errors caused by dc level errors add rather than cancel as shown in Figure 9 3 The time errors in locating the leading edge and trailing edge of the pulse reinforce rather than cancel Figure9 3 Edges ofoppositepolarityreinforce dcerrors 9 11 ...

Page 244: ...larity and for edges of opposite polarity as well as for channel to channel measurements as illustrated by Figure 9 4 If the edges have a non uniform slew rate with fast and slow regions try to reference the time interval measurement to the fastest changing region as shown in Figure 9 5 Figure9 4 Fastertransitionsdecreasee ect ofdco seterrors Figure9 5 Measuretimeintervalsat fastest changingpartof...

Page 245: ...a vertical scale factor is set to 100 mV div and an input slew rate of 1 V s the best timing resolution is 3 13 ms Summary of dc errors You can minimize the e ects of dc errors on time interval measurements by observing these guidelines when feasible Measure between identical edges same slew rate amplitude and o set Use the same dc level to reference each endpoint of the interval Reference the mea...

Page 246: ... circuit that behaves di erently from the circuit without the probe the signal at the probe tip is not the same as the signal that is present when the probe is removed Probe loading often has a more signi cant e ect on the measurement than the transient response of the instrument and must be included in the analysis of time interval measurement errors See Probe capacitive loading later in this cha...

Page 247: ...instrument and probe that have a combined rise time of 1 ns the error will be approximately 40 percent Measured rise time p 1 ns 2 1 ns 2 1 41 ns If instead you measure the same signal with an instrument and probe with a combined rise time of 330 ps the error will be reduced to approximately 5 percent Measured rise time p 1 ns 2 330 ps 2 1 05 ns Table 9 1 shows the error for other ratios of instru...

Page 248: ...level on some later edge is the same as the error in measuring rise time Narrowpulseresponse If you apply a narrow pulse to the input of the instrument the waveform is a ected in three ways 1 the height is incorrect 2 the 50 percent width is incorrect 3 the peak is shifted relative to the pulse as shown in Figure 9 6 Figure9 6 Narrow pulseappliedtothe instrument 9 16 ...

Page 249: ...height error as a function of instrument rise time and input pulse width Figure 9 7 Errorsinpulse heightmeasurement You can approximate the error in pulse width measurements by substituting pulse width for rise time If a pulse has Gaussian shape and its width is greater than three times the instrument s rise time the error in the measured pulse width will be less than ve percent and the error in p...

Page 250: ...is approximatelyequaltothe errorin10 90 rise time Probecapacitive loading The capacitance of the probe tip to ground forms an RC circuit with the output resistance of the circuit under test The time constant of this RC circuit will slow the rise time of any transitions increase the slew rate and introduce delay in the actual time of transitions The approximate rise time of a simple RC circuit is 2...

Page 251: ...cting the probes The capacitive loading of the probes can attenuate a glitch remove ringing or overshoot or slow an edge just enough that a setup or hold time violation no longer occurs Summary Minimize the e ects of transient response on time interval measurements by following these guidelines Choose an instrument and probe with a combined rise time of less than 1 3 the fastest rise time or pulse...

Page 252: ...IncreasingMeasurement Accuracy andTime Interval Measurement ...

Page 253: ...10 General Purpose Oscilloscope Menus ...

Page 254: ...atyou ll ndin thischapter The front panel keys includes the following functions Acquisition Channel Setup De ne Measure FFT Histogram Math Time Base Trigger This chapter describes each of these functions They are listed alphabetically 10 2 ...

Page 255: ...Acquisition Menu The Acquisition menu allows you to modify the way the instrument acquires the data by selecting the number of averages and record length 10 3 ...

Page 256: ...es noise on the displayed waveform improves resolution of the displayed waveform and increases measurement repeatability all due to a more stable displayed waveform However averaging slows down the throughput of the instrument Also the waveform is less responsive to changes especially when you select a high number of averages The vertical resolution can be improved to greater than 12 bits by using...

Page 257: ...aaaaaa Best This function is only available in an HP 54750A or an HP 83480A with the HP 54755A option installed The samplers used in the HP 54750A and HP 83480A systems have a certain amount of passive feedthrough This feedthrough is corrected by a compensation circuit A small amount of feedthrough does remain after compensation and this causes slight non atness in a step response Since averaging ...

Page 258: ...ommended that the auto record length be used for the above three modes The number of points in a complete record length is displayed with the Record Length key KeyPath 4Acquisition5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Record length NNNNNNNNNNNNNN Mode Automatic Manual lets you pick a record length from 16 to 4096 points Use the knob arrow keys or keypad to select a record length Bec...

Page 259: ...menu is accessed from the front panel Channel key of the appropriate plug in module There is a separate key for each channel Modules with two channels have two keys modules with one channel have one key Most menu functions only operate on the selected channel Some softkeys such as Cal Status access functions that apply to the entire module These functions can be accessed from either Channel key Th...

Page 260: ...to use the standard IEEE measurement points or by allowing you to customize the measurements with the user de ned selections Figure 10 1 is a waveform drawing that shows some of the standard measurement thresholds Refer to Chapter 7 for details about the algorithms used to calculate the thresholds for the automatic measurement features Figure 10 1 Standardmeasurement thresholds 10 8 ...

Page 261: ...es are calculated from the waveform that is on the display Make sure that the waveform is expanded vertically and horizontally so that the instrument can accurately determine the top and base values of the waveform However if too much of the top and base of the waveform is on the display it may reduce the number of sample points on the edge of interest which may reduce the repeatability of your me...

Page 262: ...the threshold is set to 110 MV you can change the threshold in 1 MV increments The upper threshold value is always greater than the value of the middle threshold and the middle threshold value is always greater than the value of the lower threshold The instrument will not allow a threshold to cross over the adjacent threshold If the threshold you are using for the measurement is not positioned on ...

Page 263: ...NNNNN Thresholds NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN user defined NNNNNNNNNNNNNNNNN Upper Adjust the upper value The marker gives you a visual indication of where the upper value is positioned on the waveform 4 Use the same procedure to adjust the middle and lower threshold values If the marker value is much greater than the threshold value the marker may be clipped o the screen aaaaaaaaaaaaaaa...

Page 264: ...ake sure there is enough of the signal displayed on the screen so that the instrument can accurately determine the top and base values of the waveform However if too much of the top and base of the waveform are on the display it may reduce the number of sample points on the edge of interest which may reduce the repeatability of your measurements A good rule of thumb is to have two divisions of top...

Page 265: ...NNNNNNNN user defined Using markerstoshow top base settings The markers can be used to give you a visual indication of where you are manually setting the top base values on a waveform 1 To use the markers to show the top base settings press 4Markers5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN measurement NNNNNNNNNNNNNNNNN Enter 4Shift5 4V amptd5 NNNNNNNNNNNNNNNNN Enter 2 Select the channel you are using ...

Page 266: ...NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Define 1time Selectingautomatic 1timemeasurements To select automatic 1time measurements press 4Shift5 41time5 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Start Edge or aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Stop Edge You can set the start edge or the stop edge to rising falling or either The selection e ects all 1time measurements KeyPath 4De ne me...

Page 267: ...lready on the display or reduce the time base scale setting so the selected edge is on the display KeyPath 4De ne meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Define 1time NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Edge number aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Edge Threshold You select both a Start Edge threshold and a Stop Edge threshold The Edge threshold choices are...

Page 268: ...aaaaaaaaa Signal type This function available with rmware revision A 02 00 and above The Signal Type function de nes the waveform types to be measured by the instrument Measurement algorithms vary depending on the type of signal being measured For example the algorithm used to determine rise time for an NRZ eye diagram is di erent from the algorithm used to measure the rise time on a single valued...

Page 269: ...cond boundary Values are entered as a percentage of bit width For example if extinction ratio is to be characterized over a complete bit interval one window boundary should be set to 0 and the other window boundary is set to 100 If the middle 20 of the eye is to be characterized one window boundary should be set to 40 and the other window boundary is set to 60 For certain eye measurements when mar...

Page 270: ...lculates the mean and standard deviation and the minimum and maximum of the automatic measurement results The statistics results are displayed below the lower right portion of the graticule area This is the same area where the marker results are displayed If the marker results are displayed instead of the statistics results either turn o the manual and waveform markers or turn o the readout for th...

Page 271: ...ence or resolution number of points Changing the channel state scale or o set Changing the trigger de nition Rede ning the waveform math function if the measurement is calculated on a function Switching the lter in or out on an optical channel Storing to memory if the measurement is calculated on a memory Clearing the display aaaaaaaaaaaaaaaaa Off The O function stops the statistics measurements r...

Page 272: ... Standard deviation measures the dispersion of those measurement results Figure 10 2 shows the mean and standard deviation more graphically Standard deviation is represented by the Greek letter sigma For a Gaussian distribution two sigma 61 from the mean is where 67 percent of the data points reside and six sigma 63 from the mean is where 99 7 percent of the data points reside Figure 10 2 Standard...

Page 273: ...is calculated as n P x2 0 0P x 12 n n 01 01 2 2 n 65 534 2 n 2 n01 n 0 1 x2 n n 65 535 n 2 n 0 n 2 n 0 1 01 2 n 65 535 Where standard deviation n count since last statistics reset x measurement result aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa min max Min minimum and max maximum are the absolute extremes of the automatic measurement KeyPath 4De ne meas5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Statistics m...

Page 274: ...ded to an instrument signals can also be displayed in the frequency domain The frequency domain allows you to see the frequency content of a signal FFT functionality added to an instrument allows you to analyze a signal from two di erent but complimentary points of view the frequency domain and the time domain 10 22 ...

Page 275: ... to the FFT function This FFT waveform is displayed in the same color used to represent waveforms on slot 3 The default color is purple KeyPath 4FFT5 NNNNNNNNNNNNNNNNNNNNNNN Display aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Source The Source function determines which signal the instrument uses to generate the FFT function As the source of the FFT function you can select channels functions memories constant ...

Page 276: ...r than those at the ends of the record For example a Hanning window looks like the rst half of a sine wave The Hanning window multiplies the points in the center of the record by 1 and multiplies the points at the start and the end of the record by zero The rectangular window is essentially no window All points in the record are multiplied by 1 The rectangular window is useful for transient signal...

Page 277: ...aaaaaaaaaaaaaa FFT Scaling The FFT Scaling softkey is displayed when the FFT Display is turned on Pressing the FFT Scaling softkey brings up either the Magnify Y Scale or Y O set menu KeyPath 4FFT5 NNNNNNNNNNNNNNNNNNNNNNN Display On NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN FFT Scaling 10 25 ...

Page 278: ...NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Magnify Span The Magnify Span softkey is displayed when Magnify is set to on The Magnify Span softkey uses software expansion to zoom in on the FFT record The span can be entered in steps of 1 2 and 5 You can also enter any magni cation spans from the keypad KeyPath 4FFT5 NNNNNNNNNNNNNNNNNNNNNNN Display On NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN FFT Scaling NNNNNNNNNNNN...

Page 279: ...N FFT Scaling NNNNNNNNNNNNNNNNNNNNNNN Y Scale aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Y Offset The Y O set function uses software expansion to move the FFT function vertically on the screen O set is the value at the center of the graticule area If you adjust the o set so that a peak is at the vertical center of the graticule area then you know that the peak magnitude is the o set value For examp...

Page 280: ...time domain signal whether it is periodic or single shot to be transformed into the frequency domain The fast Fourier transform FFT was developed as a special algorithm that speeds up the discrete Fourier transform DFT by reducing the large number of calculations that are required by DFTs Because an FFT runs 10 to 100 times faster than the traditional DFT Fourier transform calculations typically u...

Page 281: ... the signal to determine the correct frequency It turns out that the points above Fs 2 are a mirror image of the points below Fs 2 The points above Fs 2 are not displayed because they do not provide any additional information Therefore N time samples results in N 2 displayed frequency points Figure 10 3 Sinewavein thefrequencydomain Figure 10 4 shows an example The upper graticule shows a 1 GHz wa...

Page 282: ...requency domain may be new to you let s look at the second line of numbers The rst number is the vertical scale in dB div The second number is the o set in dBm at the center of the lower graticule area The third number is the horizontal scale in frequency div The fourth number is the center frequency value To maximize the use of the display area some of the instrument s features share the lower ar...

Page 283: ... A higher number of points results in more accurate measurements but also takes more computation time Depending on your application you can balance between the need for accuracy and computation speed of the FFT Frequency accuracy The frequency accuracy is the sum of two terms The rst term is supplied because there are a limited number of frequency bins and the measurement is accurate to plus or mi...

Page 284: ... the Channel menu make sure the source impedance and probe attenuation are set correctly for your application 2 In the Channel menu set the Scaling for almost full scale de ection 3 In the FFT menu use the attop window 4 Press 4Shift5 4More meas5 on the keypad then make an FFT magnitude measurement 10 32 ...

Page 285: ...m from the peak voltage dBm 20 log Vp 0 316228 V The bottom term 0 316228 volts is the peak voltage of a 1 mW signal into a 50 resistor The calculation is Vp Vrms 0 707107 p P 2R 0 707107 p 1 mW 2 50 0 707107 0 316228 V If you are measuring the power of a signal then terminate the source into 50 in order to get the correct dBm reading However if you are measuring voltage then you do not need to te...

Page 286: ... de ned as a 1 Vrms signal You can convert a dBm reading to a dBV reading by subtracting 13 dB dBV 20 log 0 707107 2Vp 1 V Which gives us dBV 20 log Vp 0 316228 V 20 log 0 707107 20 316228 V 1V Therefore dBV dBm value 013 01 dB dc value For e ciency reasons the FFT computation produces a dc value that is incorrect 10 34 ...

Page 287: ...rum as a signal of a lower frequency Because the frequency span goes from 0 to the Nyquist frequency the best way to prevent aliasing is to make sure that the frequency span is greater than the frequencies present in the input signal Keep in mind that most periodic signals that are not sine waves have frequency components that are much higher than the frequency of the signal Presetting FFT paramet...

Page 288: ...displayed waveforms Noise is measured by sizing the histogram window to a narrow portion of time and observing a vertical histogram that measures the noise on an edge Jitter is measured by sizing the histogram window to a narrow portion of voltage and observing a horizontal histogram that measures the jitter on an edge Several histogram based measurement routines have been automated and consolidat...

Page 289: ...ta or all three functions color graded display mask testing and histograms are turned o The instrument stops acquiring data when the power is cycled the Stop Single key is pressed the Run Until Mode softkey in the mask limit test or histograms menus is set to stop acquiring data after a speci ed number of waveforms or samples are acquired You can clear the database by pressing the Clear Display ke...

Page 290: ...color graded display is turned on When mask testing or histograms are turned on they take advantage of the information already established in the database as if they had been turned on the entire time Figure 10 5 shows an example histogram Figure10 5 An exampleofthehistogram display 10 38 ...

Page 291: ...the median and 50 are below the median Std dev The Standard deviation value of the histogram Hits The total number of samples included in the histogram P P The width of the histogram For horizontal histograms width is the di erence time between the rst and last pixel columns that contains data For vertical histograms width is the di erence in time between the rst and last pixel rows that contain d...

Page 292: ...histogram markers The database can be reset by pressing the Clear Display key KeyPath 4Histogram5 NNNNNNNNNNNNNN Mode NNNNNNNNNNNNNNNNNNNNNNNNNN Waveform The Waveform function displays a histogram of the data in the database that is windowed by the histogram markers KeyPath 4Histogram5 NNNNNNNNNNNNNN Mode NNNNNNNNNNNNNNNNNNNNNNNNNN waveform aaaaaaaaaaaaaaaaaaaaaa Axis The Axis function orients the...

Page 293: ...NNNNNNNNNNNNNNNNNNNNNNNN Scale Source The Scale Source softkey selects the channel or function that the window scale is derived from For example if Y1 position is set to 100 W and Y2 position is set to 0 W the distance between the histogram markers depends on the vertical scaling of the source If the source is set to 50 W div the markers will be two divisions apart If the source is set to 500 W di...

Page 294: ...m markers so that the histogram is built from a very narrow horizontal slice of the graticule area For noise measurements you would position the X1 and X2 histogram markers so that the histogram is built from a very narrow vertical slice of the graticule area KeyPath 4Histogram5 NNNNNNNNNNNNNN Mode NNNNNNNNNNNNNNNNNNNNNNNNNN waveform NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Hist window NNNNNNNNNNNNNNNN...

Page 295: ...ts to dB x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 Linear scale For linear scale type the scale is in the percentage of the peak per division For example on a horizontal histogram 20 places one fth of the histogram in each of eight divisions with the top of the peak 100 at the middle of the display NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Log scale For log scale type the...

Page 296: ...edge of the display The histogram is plotted according to the following formula dB 20 log X peak where X is the number of hits per column for horizontal histograms or the number of hits per row for vertical histograms Peak is the number of hits in the peak dB is the log value that gets plotted This means 0 dB is at the peak of the histogram and the o set can only contain negative values For exampl...

Page 297: ... peak per division or dB By changing the scale you can zoom in or out on the histogram O set allows you to pan across the histogram by moving the base of the histogram Depending on the setting of the Scale Type softkey the o set value is also in either percent of peak or dB per division KeyPath 4Histogram5 NNNNNNNNNNNNNN Mode NNNNNNNNNNNNNNNNNNNNNNNNNN waveform NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN His...

Page 298: ...f a math operator and either one or two operands A function is calculated on data adjusted by the calibration factors and a new waveform called a function is generated by the computation You can place markers on functions make measurements on functions or store functions to waveform memories 10 46 ...

Page 299: ...or operands KeyPath 4Math5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Define Function NNNNNNNNNNNNNNNNNNNNNNNNNN Operator You can select any of the math functions as the math operator to act on the operand or operands To see the resultant waveform simply turn the Function display on KeyPath 4Math5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Define Function NNNNNNNNNNNNNNNNNNNNNNNNNN Opera...

Page 300: ...ubtract NNNNNNNNNNNNNNNNNNNNNNNNNN multiply Multiplies point by point operand 1 and operand 2 Use multiply to make electrical power measurements KeyPath 4Math5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Define Function NNNNNNNNNNNNNNNNNNNNNNNNNN Operator NNNNNNNNNNNNNNNNNNNNNNNNNN multiply NNNNNNNNNNNNNNNNNNNN divide Divides point by point operand 1 by operand 2 KeyPath 4Math5 NNNNNNNNNNNNNNN...

Page 301: ...NNNNNN min Minimum stores the minimum value acquired in each time bucket on operand 1 KeyPath 4Math5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Define Function NNNNNNNNNNNNNNNNNNNNNNNNNN Operator NNNNNNNNNNN min NNNNNNNNNNN max Maximum stores the maximum value acquired in each time bucket on operand 1 The results for minimum and maximum are recalculated when any of the following occurs Time b...

Page 302: ...NNNNNNNNNNNNNNN Operand The math operator is performed either on operand 1 or on operand 1 and operand 2 The number of operands used depends on the math operator you select For example add requires two operands while invert requires only one operand Operand lets you select from channels functions waveform memories or a constant If the operand waveforms have di erent record lengths the function use...

Page 303: ...ta When display is set to on the function is calculated and displayed Turning the display to o ends function computation and erases the function from the display Function 1 is displayed in the same color that is used to display signals from slot 1 and function 2 is displayed in the same color that is used to display signals from slot 2 KeyPath 4Math5 NNNNNNNNNNNNNNNNNNNNNNN Display NNNNNNNNNNNNNNN...

Page 304: ... to select either track source or manual Track source makes the function use the same vertical scale and o set of the function s waveform source Manual allows you to set the vertical scale and o set independently of the waveform source Increased resolution in scale and o set can be achieved KeyPath 4Math5 NNNNNNNNNNNNNNNNNNNNNNN Display NNNNNNNN On NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN...

Page 305: ... Base Menu This section contains a description of the Time Base menu and how it controls the horizontal portion of the display The topics covered are horizontal scale position reference and windowing 10 53 ...

Page 306: ...lay two bits or eyes you can simply set the scale to two bits Refer to the Scale softkey earlier in this chapter KeyPath 4Time Base5 NNNNNNNNNNNNNNNNN Units aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Bit rate This function is only available with the HP 83480A or if the HP 83480K option is installed in an HP 54750A Bit rate allows the time base to be con gured for a variety of standard optical and e...

Page 307: ...m the numeric keypad To enter values in Mb s enter the number followed by 4Eex5 465 To enter values in Gb s enter the number followed by 4Eex5 495 When the instrument is stopped and you expand the scale the instrument redisplays the signal at the new scale setting This feature allows you to zoom in or to zoom out on the signal If you watch the memory bar at the top of the display you can see what ...

Page 308: ...3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 Center reference The data is acquired evenly on both sides of the reference point The data in the waveform record is centered around the reference point and changing the scale expands or contracts the signal about the center of the display x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x ...

Page 309: ...ndow marker is placed on the signal The window marker de nes the portion of the signal you plan to expand However the color highlight is not available when mask testing is turned on The default color of the window marker is red but you can change the window marker color in the Display menu NNNNNNNNNNNNNNNNNNNNN Window The Window function expands and displays the portion of the signal that is outli...

Page 310: ...e intensi ed marker horizontally across the main sweep It allows you to precisely pick the segment of the main sweep you wish to expand for further analysis KeyPath 4Time Base5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Time base windowing NNNNNNNNNNNNNNNNNNNN Enable NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Window Position 10 58 ...

Page 311: ... Trigger menu and explains how you can use its controls to trigger the instrument The trigger circuit performs two functions It locates the waveform of interest and it synchronizes the instrument measurement and display to the waveform 10 59 ...

Page 312: ...play There are three green LEDs at the top left corner of the mainframe When a LED is lit it indicates the trigger status of the instrument Armed The instrument is waiting for a trigger event to occur Triggered The instrument triggered on a valid trigger event Freerun The instrument is automatically triggered as soon as it is armed This is useful for seeing a waveform untriggered or for looking at...

Page 313: ...orces the instrument to trigger when armed giving you glimpses of the signal which then allows you to set up channel vertical scales to display signals KeyPath 4Trigger5 NNNNNNNNNNNNNNNNN Sweep NNNNNNNNNNNNNNNNNNNNNNN freerun aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Source The Source function displays a list of the available trigger sources The list of available trigger sources depends on the combination o...

Page 314: ...NNNNNNNNNNNNNNNNNN External Scale aaaaaaaaaaaaaaaaaaaaaaaaaa Level Level speci es the voltage threshold that a signal must cross in order for the instrument to trigger on that signal You can use the knob arrow keys or keypad to change the trigger level You can adjust the trigger level from within any of the trigger submenus The trigger level setting also determines what the instrument uses as a re...

Page 315: ...aaaaaaaaaaaaaaaaaa Hysteresis The Hysteresis function de nes the amount of hysteresis around the trigger point Selections include normal and high sensitivity KeyPath 4Trigger5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Hysteresis aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Trig Bandwidth The Trig Bandwidth function brings up a second level softkey menu on the display The Trig Bandw...

Page 316: ...ger bandwidth mode can not be used when the HP 83480A is performing eyeline measurements Use the NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN DC 2 5 GHz mode instead This function is available on the HP 83480A Option 100 only KeyPath 4Trigger5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Trig Bandwidth NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN 2 12 GHz Gate NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN DC 2 5 GHz The DC 2...

Page 317: ...11 The General Function Menus ...

Page 318: ...The General Function Menus Whatyou ll ndin thischapter This chapter describes the following menus Disk Display Limit Test Marker Setup Setup Print Utility Waveform 11 2 ...

Page 319: ...ont panel setups delete les from a disk format a disk or obtain a directory listing of a disk In other menus you can use the disk drive to load applications load new system rmware or save a copy of the display information in a TIFF GIF PCX or printer speci c format You can choose from ve di erent disk operations directory load store delete and format 11 3 ...

Page 320: ...ailable space left on the disk When you press the 4Disk5 key to enter the Disk menu the instrument checks to see if a disk is in the drive If there is a disk in the drive you will see a directory listing of all the les on the disk If there is no disk in the drive the screen displays the message There is no disk in the drive Then the Disk softkey menu is displayed KeyPath 4Disk5 NNNNNNNNNNNNNNNNNNN...

Page 321: ...new disk in the drive and you need to see a listing of the les on the new disk If the type of le is not recognized by the instrument the type eld is left blank Also the instrument lists only those les that are in the root directory of the disk All other directories on the disk are listed like les except that a le extension is not appended to the lename and the le size is listed as 0 bytes Any les ...

Page 322: ...xtension is determined by the type of le and format you selected Waveform and waveform text les are loaded into one of the four waveform memories by overwriting any data previously stored in that waveform memory Color grade les are read directly into the instrument by overwriting the previous color grade Pixel les are loaded in the pixel memory by overwriting any data previously stored in the pixe...

Page 323: ...tion and reference plane calibration factors The TDR plug in module must be the same one used to establish the stored normalization and reference plane calibration factors The time base values must be set to the same values used when the stored normalization and reference plane calibration factors were established Because the normalization and reference plane calibration factors depend on the time...

Page 324: ...function the instrument stores the information to whichever le name is listed under the To File softkey If the le already exists on the disk you are prompted to press the Continue key before the le on the disk is overwritten You can either press the Continue key to overwrite the le or you can press the To File softkey and enter a new le name After the le is written to the disk the le listing on th...

Page 325: ...NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN TDR TDT cals HP 54750A only The HP 54750A mainframe has an additional menu selection TDR TDT cals which allows previously stored normalization and reference plane calibration factors to be loaded for the HP 54653A 54754 TDR plug in modules Before the calibration factors can be stored an establish normalization and reference plane procedure must be performed Re...

Page 326: ...N delete aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa format The Format function allows you to format 3 1 2 inch high density disks in the instrument The formatted disks are MS DOS R compatible and can be used in other MS DOSR compatible disk drives You may notice there is a faster disk access time when you use disks in the instrument that were formatted by the instrument This is because some computers and dis...

Page 327: ...l setups MSK for masks TDR for TDR TDT calibrations HP 54750A rmware Rev A 02 00 and higher only The PCL TIF GIF and PCX le extensions are used by the Setup Print menu KeyPath 4Disk5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Operation NNNNNNNNNNNNNN load NNNNNNNNNNNNNNNNN Enter NNNNNNNNNNNNNN Type NNNNNNNNNNNNNNNNNNNNNNNNNN Waveform The waveform le type is for storing waveforms to a disk or loading waveforms ...

Page 328: ...ou can use pixel les as a template to compare other waveforms against or you can make timing diagrams for signal analysis When you load a pixel le into the instrument it is loaded into the pixel memory by overwriting all data that was previously stored in the pixel memory KeyPath 4Disk5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Operation NNNNNNNNNNNNNN load NNNNNNNNNNNNNNNNN Enter NNNNNNNNNNNNNN Type NNNNNNNN...

Page 329: ...ing a mask to a disk or for loading a mask le from a disk A mask le is stored in an ASCII format only and mask les have a MSK le extension KeyPath 4Disk5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Operation NNNNNNNNNNNNNN load NNNNNNNNNNNNNNNNN Enter NNNNNNNNNNNNNN Type NNNNNNNNNNNNNN mask 11 13 ...

Page 330: ...if you try to read it in a word processing program it will give you meaningless information However this is the preferred waveform storage method because the les take up one third as much disk space as text les You can always convert them to text les at a later date Internal format les have a WAV le extension Waveform les stored using the internal format contain the vertical and horizontal scaling...

Page 331: ...aracters to uppercase the header information can be a mix of uppercase and lowercase characters There must be at least one space between a header and its corresponding data For example there must be at least one space between Type and raw Error Messages If you have modi ed the header information and a header eld is omitted the instrument sets that eld to the default value The default values are li...

Page 332: ...econd Y Units Watt Max bandwidth 12400000000 Min bandwidth 0 Data 6 646E 04 1 431E 04 1 169E 04 7 367E 04 1 441E 04 1 640E 04 6 898E 04 7 725E 04 6 961E 04 8 162E 04 5 01E 05 1 316E 04 7 024E 04 6 46E 05 6 667E 04 7 653E 04 1 148E 04 6 866E 04 1 211E 04 1 504E 04 6 992E 04 7 890E 04 1 274E 04 1 399E 04 7 140E 04 1 242E 04 4 50E 05 7 776E 04 1 158E 04 6 562E 04 7 510E 04 8 778E 04 7 357E 04 1 326E ...

Page 333: ...etween data points on the X axis X increment is equal to the YData range value for versus waveforms The default value is calculated XOrg X origin is the x value of the rst data point in the data record X origin is equal to the YData center value for versus waveforms The default value is 22E 9 XRef X reference is always set to zero when it is read back into the instrument The default value is 0 YDa...

Page 334: ...he sampling mode used to acquire the waveform which is always sequential The default value is sequential Completion Completion represents the percent of the time buckets in the waveform record that contain data The number of time buckets is equal to the number of points in the waveform record Completion is ignored when it is read back into the instrument The default value is 100 X Units X units is...

Page 335: ... the front of the le Table 11 2 shows a partial example of the text Y values format Text Y values les also have a TXT le extension KeyPath 4Disk5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Operation NNNNNNNNNNNNNN load NNNNNNNNNNNNNNNNN Enter NNNNNNNNNNNNNN Type NNNNNNNNNNNNNNNNNNNNNNNNNN waveform NNNNNNNNNNNNNNNNN Enter NNNNNNNNNNNNNNNNNNNN Format NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN text y values 11 19 ...

Page 336: ...3E 04 1 011E 04 1 305E 04 6 406E 04 7 003E 04 1 462E 04 1 148E 04 1 137E 04 1 263E 04 7 964E 04 1 085E 04 7 014E 04 6 573E 04 7 828E 04 7 182E 04 6 856E 04 1 399E 04 1 221E 04 7 571E 04 7 932E 04 9 48E 05 6 490E 04 7 398E 04 4 50E 05 9 80E 05 8 96E 05 7 510E 04 1 116E 04 1 106E 04 1 001E 04 7 932E 04 6 291E 04 7 337E 04 8 54E 05 1 033E 04 3 88E 05 6 961E 04 7 530E 04 7 306E 04 1 095E 04 7 839E 04 ...

Page 337: ...t to change the present setup of the instrument An example of the mask only format is shown below KeyPath 4Disk5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Operation NNNNNNNNNNNNNNNNN store NNNNNNNNNNNNNNNNN Enter NNNNNNNNNNNNNN Type NNNNNNNNNNNNNN mask NNNNNNNNNNNNNNNNN Enter NNNNNNNNNNNNNNNNNNNN Format STM16 OC48 polygon number 1 number of vertices 4 0 400 0 250 0 600 0 250 0 600 0 750 0 400 0 750 polygon nu...

Page 338: ...number in the character list Press 4Enter5 to enter that character into the le name eld You can also use the keypad to enter numbers into the lename The arrow keys move the cursor forward and backward through the le name The Backspace softkey backspaces over characters in the le name The Delete softkey deletes characters from the le name Press 4Clr5 on the keypad to erase the le name from the menu...

Page 339: ...to which you can load a waveform This function is available when the waveform type is selected The instrument overwrites any data that was previously stored in the waveform memory KeyPath 4Disk5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Operation NNNNNNNNNNNNNN load NNNNNNNNNNNNNN Type NNNNNNNNNNNNNNNNNNNNNNNNNN waveform NNNNNNNNNNNNNNNNNNNNNNNNNNNNN To memory 11 23 ...

Page 340: ...e how the acquired data is displayed on the screen You can select the graticule settings and you can change the color of most of the items that are displayed on the screen You can also annotate waveforms by using the Label menus to add text to the waveform viewing area 11 24 ...

Page 341: ...sistence time you have selected Therefore the longer the persistence time the longer each data point is left on the display before it is erased from the display You can change the persistence time with the knob arrow keys or keypad The variable persistence mode has a feature called gray scaling On older digitizing oscilloscopes pixels were either turned on to full brightness or turned o This gave ...

Page 342: ...ine which points make up individual waveforms The relative ages of waveforms can be determined The direction in which a waveform is changing can be determined The value of a waveform inside a waveform envelope can be determined KeyPath 4Display5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Persistence NNNNNNNNNNNNNNNNNNNNNNNNNN variable NNNNNNNNNNNNNNNNNNNNNNNNNN infinite You can use in nite persistence fo...

Page 343: ...Each color represents a range of counts and the range depends on the total number of hits As the total count increases the range of hits represented by each color also increases Color Grade is automatically implemented when performing automatic eye measurements In this case the displayed data corresponds directly to the database used to perform the eye measurements KeyPath 4Display5 NNNNNNNNNNNNNN...

Page 344: ...NNNNNNNNNNNNN fast NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN connected dots The Connected Dots function draws a straight line through the data points on the display On waveforms where there are only a few dots representing the acquired data points such as when the record length is small you may nd it easier to have a sense of what the waveform looks like Figure 11 2 shows a waveform with only d...

Page 345: ...The General Function Menus DisplayMenu Figure11 3 Connecteddots 11 29 ...

Page 346: ...lay actually has When the data point lies between adjacent pixels the instrument lights up both pixels but varies the brightness of each pixel The brightness of each pixel is proportional to how close it is to the data point Your eye is then drawn to a point between the two pixels to the data point However this increased vertical resolution does take microprocessor time which slows down the displa...

Page 347: ...NNNNNNNNNNNNNNNNNNNNNN Graticule NNNNNNNNNNNNNN Type NNNNNNNNNNNNNN grid Grid overlays a graticule on the waveform display area that has ten major horizontal divisions and eight major vertical divisions There are also tick marks on the axis to indicate minor divisions Vertically one minor division is one quarter of a major division and horizontally one minor division is one fth of a major division...

Page 348: ...yPath 4Display5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Graticule NNNNNNNNNNNNNN Type NNNNNNNNNNNNNNNNN frame NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Intensity Intensity controls the brightness of the horizontal and vertical graticule markings You can vary the brightness from 0 o to 100 very bright Use the knob arrow keys or keypad to set the intensity level of the graticule You can also change the color of the grati...

Page 349: ...NN Graphs Figure11 6 Screeninframe modeusingtwographs NNNNNNNNNNNNNNNNNNNNNNNNNN Waveform Waveform lets you select from channels functions or memories Whatever is selected with the Waveform function is placed into the graph chosen by the Location function KeyPath 4Display5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Graticule NNNNNNNNNNNNNNNNNNNN Graphs NNNNN 2 NNNNNNNNNNNNNNNNNNNNNNNNNN Waveform NNNNNNNNNNNNNN...

Page 350: ...4 horizontal columns 0 63 Label position 0 0 is the upper left hand corner and position 18 63 is the lower right hand corner KeyPath 4Display5 NNNNNNNNNNNNNNNNN Label NNNNNNNNNNNNNNNNNNNNNNN Display The Display function allows you to turn the labels o and on KeyPath 4Display5 NNNNNNNNNNNNNNNNN Label NNNNNNNNNNNNNNNNNNNNNNN Display x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3...

Page 351: ...NNNNNNNNNNNNN Label NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Define new label NNNNNNNNNNN Row NNNNNNNNNNNNNNNNNNNN Column The Column function allows you to select one of the 64 horizontal columns where the label is placed KeyPath 4Display5 NNNNNNNNNNNNNNNNN Label NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Define new label NNNNNNNNNNNNNNNNNNNN Column 11 35 ...

Page 352: ...tkey To delete a character from the le name use the arrow key to position the cursor over that character then press Delete If labels overlap on the display only the last label de ned is displayed The previous label is not erased it is hidden by the last label de ned Either use the Modify Label function to reposition one of the labels or use the Delete Label function to erase one of the labels from...

Page 353: ... 19 vertical rows where you want to relocate the label KeyPath 4Display5 NNNNNNNNNNNNNNNNN Label NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Modify label NNNNNNNNNNN Row NNNNNNNNNNNNNNNNNNNN Column The Column softkey allows you to select one of the 64 horizontal columns where you want the label to relocate the label KeyPath 4Display5 NNNNNNNNNNNNNNNNN Label NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Modify...

Page 354: ...from the display You must select a label highlight before you can delete it KeyPath 4Display5 NNNNNNNNNNNNNNNNN Label NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Delete NNNNNNNNNNNNNNNNNNNN Delete aaaaaaaaaaaaaaaaaaaaaaaaaa Color The Color menu allows you to modify the color of most items that are displayed on the screen KeyPath 4Display5 NNNNNNNNNNNNNNNNN Color NNNNNNNNNNNNNNNNN Color The Color softkey allows ...

Page 355: ...r The color of the time base window marker Marker The color of the waveform markers Graticule Color of the graticule grid lines and tick marks Trace background The color the waveform viewing area graticule background Error The color of error messages Advisory The color of advisory messages and prompts Examples of advisory messages are Storing and Setup saved Status The color of status messages Exa...

Page 356: ... color graded display is turned on you may also change the colors used for the color graded display These colors are labeled Db level 1 least hits Db level 2 Db level 7 most hits The color graded display must be on to change these colors NNNNNNNNNNN Hue Hue is the gradation of color You can use the knob arrow keys or keypad to vary the hue from 0 to 100 Red is at both 0 and 100 green is at 33 and ...

Page 357: ...The Default Colors softkey sets the instrument to the default colors The default display colors were selected to Improve the appearance of the display Help you discern which waveform is on which channel by making each channel a separate easy to identify color Bring error messages to your attention by displaying them in red However you may prefer to change the color scheme to t your personal tastes...

Page 358: ...re measurement results with pass or fail limits without having to use an external controller Limit test independently tracks up to four measurements and you can determine the fail action the instrument takes To select the Limit Test menu press 4Limit test5 11 42 ...

Page 359: ...tion Menus LimitTestMenu Figure 11 7 is a functional view of the limit test Notice the test summary screen dumps and waveforms can each be sent to di erent destinations Figure11 7 A functionalviewofthe limittest 11 43 ...

Page 360: ...st softkey to o after completion of the test the test results are removed from the screen KeyPath 4Limit test5 NNNNNNNNNNNNNN Test aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Measurement The limit test runs on all active measurements There can be up to four active measurements The Measurement softkey allows you to select each of the measurements and con gure the Fail When Upper Limit a...

Page 361: ...s the instrument to fail on a test every time the measurement is executed and the parameters set by the Lower Limit and Upper Limit softkeys are ignored Use the Fail Always mode when you want to log the action each time the measurement is executed Fail always allows you to monitor trends in measurements For example you may want to track a measurement during an environmental test while the instrume...

Page 362: ...NNNNNNN Pass You might use the pass parameter when triggering on one event and measuring another event that may not occur on every trigger For example in a communications system you may want to trigger on the clock and test the rise times of edges in the data stream However there may be no way to guarantee that a rising edge is present to measure in the data stream at every clock edge By using the...

Page 363: ...asurement is selected with the Measurement softkey KeyPath 4Limit test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Upper limit aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Lower Limit The Lower Limit softkey sets the lower failure threshold The units depend on which measurement is selected with the Measurement softkey KeyPath 4Limit test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Lower limit 11 47 ...

Page 364: ...ns the limit test until you turn the test o Use the forever mode when you want a measurement to run continually and to not stop after a xed number of failures For example you may want the limit test to run overnight and not be limited by a number of failures NNNNNNNNNNNNNNNNNNNNNNNNNN Failures Failures runs the limit test until a set number of failures occurs When failures is selected another soft...

Page 365: ...er of waveforms from 1 to 1 billion Use the waveforms mode when you want the limit test to reach completion after a set number of waveforms are acquired The test terminates with the measurement that rst reaches the speci ed number of waveforms KeyPath 4Limit test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Run Until NNNNNNNNNNNNNN Mode NNNNNNNNNNNNNNNNNNNNNNN forever or NNNNNNNNNNNNNNNNNNNNNNNNNN failures or N...

Page 366: ...d to include the most recent number of failures The second part is the log of the test results After each failure all of the measurement parameters at the time of the failure are logged to the summary After the limit test is complete the summary contains a log of all the measurement results at each failure When a failure does not occur during a set of measurements the header information is updated...

Page 367: ...mary le is also started Selecting a measurement Turning on the display of the signal under measurement Changing the channel state scale or o set for the measurement on that channel Rede ning a waveform math function if the measurement is calculated on that function Storing to memory for the measurements calculated on that memory Change the upper or lower limits Change the fail when mode The store ...

Page 368: ...over again at SUMM0000 SUM Theoretically you can have up to 9 999 summary les However there are two limits that keep you from obtaining that many les The rst limit is with MS DOS itself MS DOS limits the root directory to 224 entries an entry is either a le name or subdirectory Because the instrument can only access les in the root directory that limits the maximum number of les the instrument can...

Page 369: ...disk is write protected An MS DOS disk is not in the drive The disk is full The maximum number of 224 les are already stored on the disk KeyPath 4Limit test5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Store summary NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Destination NNNNNNNNNNN off or NNNNNNNNNNNNNNNNNNNNNNN printer or NNNNNNNNNNNNNN disk 11 53 ...

Page 370: ...ored in the pixel memory The only way to clear the pixel memory is from the Waveform menu The value of the pixel memory selection is that you can save the waveform area from multiple failures to the pixel memory and have a composite view of the failures Refer to Waveform Menu for additional information on the pixel memory NNNNNNNNNNNNNNNNNNNNNNN Printer Printer sends the image copy of the waveform...

Page 371: ...d NNNNNNNNNNNNNNNNNNNN Memory Memory stores a copy of what the Source softkey is set to to one of the four waveform memories the same waveform memories that are accessed by the Waveform menu Because a waveform memory can contain only one waveform at a time a waveform memory is best used when you are looking for one failure You can send either the waveform that failed or another waveform to the wav...

Page 372: ...ker menu allows you to turn on and position colored markers on the display The default marker color is orange However it can be changed to a di erent color in the Display menu You can use the markers to make custom measurements to use as visual reference points on the display or to show you where the last automatic measurement was made on the signal 11 56 ...

Page 373: ...y The X1 and X2 markers are two vertical lines you can move side to side and the Y1 and Y2 markers are two horizontal lines you can move up or down You can position the manual markers anywhere on the display which allows you to make custom measurements The manual markers track the time and voltage values as the timebase and vertical scale are changed which allows you to make accurate delay measure...

Page 374: ...NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN X1 Position and NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN X2 Position The X1 Position function moves the X1 marker horizontally and the X2 Position function moves the X2 marker horizontally The position of each marker is displayed in the same color as the markers near the bottom of the display Use the knob arrow keys or keypad to change the marker position You can make t...

Page 375: ...NNNNN manual NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Y1 Position 4Marker5 NNNNNNNNNNNNNN Mode NNNNNNNNNNNNNNNNNNNN manual NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Y2 Position aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa waveform There are two waveform markers and X The waveform markers track the waveform data in memory rather than on the displayed waveform Because the waveform data in memory has a much greate...

Page 376: ...NNNNNNNNNNNN X Source NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Position and NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN X Position The marker is controlled by the Position function and the X marker is controlled by the X Position function Use the knob arrow keys or keypad to position the markers on the signal The marker position readouts are displayed near the bottom of the display Each waveform marker has a Y position...

Page 377: ...isplayed if you do not have an automatic measurement active The markers follow the last measurement and the last measurement is displayed in the same color as the markers KeyPath 4Marker5 NNNNNNNNNNNNNN Mode NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN measurement NNNNNNNNNNNNNNNNNNNNNNN Readout The Readout function determines whether or not the measurement marker positions are shown at the bottom of the d...

Page 378: ...nly available in an HP 54750A or an HP 83480A with the HP 54755A option installed There are two waveform markers and X The waveform markers track the waveform data in memory rather than on the displayed waveform Because the waveform data in memory has a much greater resolution than the display the measurements you make with the waveform markers are much more precise than measurements made with the...

Page 379: ...y are positioned o the display You may notice that it can take a long time to bring the markers back onto the display with the knob If you set the marker position to the time base position value this will snap the marker to the same location as the time base reference The time base position value is displayed on the screen below the waveform viewing area and to the right of the time base reference...

Page 380: ...ile memories You can use the setup memories for rapidly recalling setups for production test environments or when you are comparing waveforms by using more than one setup You can also set the instrument to its default settings These settings set the instrument to a known operating condition 11 64 ...

Page 381: ...one else changes the setup when they are using it In situations where you need more than ten front panel setups or in work groups where you want to make sure that someone does not accidentally overwrite your saved setups you can save setups to a disk Refer to the Disk menu earlier in this chapter for information on saving to a disk KeyPath 4Setup5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Setup memor...

Page 382: ...ible to capabilities of the new plug in KeyPath 4Setup5 NNNNNNNNNNNNNNNNNNNN Recall aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Default setup The Default Setup function returns the instrument to its default settings The default settings place the instrument in a known operating condition This known operating condition is used as a starting point in the service procedures You m...

Page 383: ...ve Trigger BW 2 5 GHz Acquisition Record length Automatic Averaging O of averages 16 Display Persistence Variable Intensity 20 Persistence time Minimum Graphs 1 Draw waveforms Fast Labels O Graticule Grid Colors Default Color grade Color grade O Refresh rate 1 s Marker Mode Measurement X1 Y1 source First available channel Readout O X1 position 22 ns Waveform source First available channel Y1 posit...

Page 384: ...ack source Function state O Horizontal scaling Track source Operator Magnify Operand 1 First available channel or memory 1 Operand 2 First available channel or memory 1 Channel Display On Bandwidth 20 GHz Scale 50 W div or 10 mV div Units Volts or Watts O set 0 V or 0 W External o set 0 0 Attenuation units Ratio External gain 1 0 Attenuation 1 0 1 Optical lter O Wavelength 1 310 m Histogram Mode O...

Page 385: ...tside Run until waveforms 1 000 000 waveforms Upper limit 10 Store summary O Lower limit 010 Store screen O Store waveforms O Mask test Test O Run until Forever Scale source Channel 1 Failed waveforms 1 failure X1 position 22 ns Failed samples 1 sample 1X 10 ns Waveforms 1 000 000 1 level 400 nW or 0 0 V Samples 1 000 000 0 level 0400 nW or 0200 mV Store waveforms O Store summary O Store screen O ...

Page 386: ...en to the device selected in the Setup Print menu If that device is not connected to the instrument the screen displays the message Print canceled Printer is not responding When you are printing to a printer the time and date of the printout is also printed at the top of the printed data The date and time are the same as the instrument s If they are incorrect you can change the date and time in th...

Page 387: ...re 11 8 is displayed The exact screen displayed depends on the selected print format The default format is ThinkJet Figure 11 8 SetupPrintscreen The PaintJet LaserJet DeskJet and Epson screens are similar to the ThinkJet screen and the PCX color TIFF and GIF screens are similar to the TIFF screen 11 71 ...

Page 388: ...ograms The resolution is 576 x 368 pixels so you need a super VGA display on your PC to see a complete screen image at 256 colors Also the TIFF and color TIFF les comply with the TIFF 5 0 le format Even though you select a printer as a print format you can still select the disk as the destination instead of a printer The resulting le is in the format for the selected printer If a printer is not co...

Page 389: ...NNNNNNNNNNNNNNNNNNNNNNN Page length NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Form Feed Form feed allows you to turn on or o the form feed feature When on the instrument sends a form feed command to the printer after the printing of the data is complete KeyPath 4Setup print5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Print format PaintJet NNNNNNNNNNNNNNNNN Enter NNNNNNNNNNNNNNNNNNNNNNNNNNNNN Form feed NNNNNNNNNNN...

Page 390: ...tination allows you to select where to send the data If the destination device is not connected to the instrument the screen displays the message Print canceled Printer is not responding KeyPath 4Setup print5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Destination NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Centronics Centronics prints to the parallel port on the rear panel of the instrument KeyPath 4Setup print5 NN...

Page 391: ... any of the characters from the character list in any order or combination The le name cannot exceed eight characters To move the cursor through the character list use the knob To select a character from the character list use the enter key on the keypad To enter numbers into the le name use the keypad or select numbers from the character list To move the cursor through the le name use the arrow k...

Page 392: ...NNNNNNNN Graticule Graticule prints only the waveform viewing area graticule area to the printer or to the disk If you turn on Setup factors the channel time base and trigger setups are also printed NNNNNNNNNNNNNNNNNNNN Screen Screen prints the entire screen area to a printer or a disk If you turn on Setup factors the channel time base and trigger setups are also printed NNNNNNNNNNNNNNNNNNNNNNN Fa...

Page 393: ...ault translation in the MS DOS to MAC menu 3 Use a le editing utility like ResEdit 2 1 available from Apple Computer Inc Macintosh ftp archive sites or a local Macintosh User s group to open the TIFF le that you translated from MS DOS R format to the Macintosh computer To use ResEdit choose Get File Folder Info from the File menu Change the Type eld to TIFF for TIF les or change the Type eld to GI...

Page 394: ...Utility Menu The Utility menu allows you access to these six additional softkey menus HP IB Setup System Con guration Calibrate Self Test Firmware Support and Service 11 78 ...

Page 395: ...t on the bus has a separate identifying address so the computer or controller can communicate with one instrument at a time The HP IB Setup menu lets you select an address from 0 to 31 The address number you select is the address that a computer or controller uses to communicate with the instrument The default HP IB address for analyzers is 7 KeyPath 4Utility5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN...

Page 396: ...to Figure 11 9 The System Con guration menu gives you information about the mainframe and plug ins It allows you to set the date and time on the clock inside the mainframe It also allows you to update the system rmware and to declassify the memory in the mainframe KeyPath 4Utility5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN System config Figure11 9 TheSystemCon gurationdisplay 11 80 ...

Page 397: ...complete set of self tests from the Self Test menu Firmware Revision Indicates the revision number of the system rmware that is installed in the ash ROM memory Boot Revision Indicates the boot ROM version in the mainframe The boot ROM uncompresses les and loads new system rmware from the disk drive Slot Indicates the slot where each board is installed PowerStatistics Total Pon time Power on The am...

Page 398: ...ch inside the plug in This switch is for the memory in the plug in that contains the calibration factors from the last plug in calibration This switch is normally set to the protected position before performing a normal plug in calibration set the switch to the unprotected position Make sure that you return it to the protected position after completing the calibration NNNNNNNNNNNNNN Time and NNNNN...

Page 399: ...situations when you are concerned about the security of the work you are performing For example you would declassify the mainframe when you are going to leave the instrument unattended for a while or when someone is visiting your area that does not have the clearance to know about your work When the instrument is not declassi ed there is always the possibility that someone could analyze the front ...

Page 400: ...onditions KeyPath 4Utility5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN System config NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Declassify frame memory x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 Update System Firmware The operating system for...

Page 401: ... the features for this key KeyPath 4Utility5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Calibrate NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Calibrate plug in x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 x 3 Calibrate Frame The Calibrate Frame softkey is for performing service work on the instrument Refer to the Service Guid...

Page 402: ...NNNNNNNNNN Cal Status When the Cal Status softkey is set to on a screen similar to Figure 11 10 is displayed KeyPath 4Utility5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Calibrate NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Cal status Figure11 10 A typicalCalStatusdisplay 11 86 ...

Page 403: ... uncalibrated Below the Frame Calibration Status line is a display of each slot and whether the slot passed or failed the calibration If any part of the calibration process fails then the Frame Calibration Status line also displays failed Slot Indicates the slot where each plug in is installed Model Indicates the model number of the plug in If a plug in is not installed in a slot the model number ...

Page 404: ...NNNNNNNNNNNNNNNNNNNNNNNNNN Calibrate NNNNNNNNNNNNNNNNN level NNNNNNNNNNNNNNNNNNNNNNNNNN Samplers This function enables or disables samplers for service See Service Guide KeyPath 4Utility5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Calibrate NNNNNNNNNNNNNNNNNNNNNNNNNN Samplers Output Output lets you select the output signal for the front panel CAL signal on the mainframe The output is dc and can be adj...

Page 405: ...m report form or the rmware request form You may not have originally purchased the instrument or you may share the instrument with several coworkers These forms are your way of communicating with the manufacturer of the instrument Hewlett Packard Because both forms reside in the memory of the instrument you can print out a copy of either form whenever you need one KeyPath 4Utility5 NNNNNNNNNNNNNNN...

Page 406: ... Packard You can print out a problem report by simply connecting a printer to the instrument selecting printer in the Setup Print menu then pressing the Print problem report softkey If a printer is not available make a copy of the form at the end of this chapter aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Service The Service function is for performing service work on the instrument Refer to...

Page 407: ...Country Code Phone Number Street Address Fax Number Mail Stop Department City Prov State Postal Zip Code Country Date Problem Report Classi cation Hardware Mechanical Problem Documentation Problem Software Firmware Problem Remote Programming Problem Suggested Enhancement Problem Description 11 91 ...

Page 408: ...n 1 model number Serial number Plug in 2 model number Serial number Plug in 3 model number Serial number Plug in 4 model number Serial number How would you prefer to be contacted Mail Fax Phone Who is your local HP sales representative Return this form to Hewlett Packard Hewlett Packard Company Service Manager MS 1US F 1412 Fountaingrove Parkway Santa Rosa CA 95403 1799 USA Fax Number 707 577 5221...

Page 409: ...save or recall a waveform to a waveform memory or to the pixel memory When you recall a waveform from a waveform memory or the pixel memory it is displayed in the default color blue However you can change the default color in the Display menu 11 93 ...

Page 410: ...NNNNNNNNNNN waveform NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Current memory The Current Memory softkey simply shows the currently selected memory When the display for a memory is turned on the bar below the memory lls in and turns blue The default color is blue If the display memory is turned o an open white box default color is displayed KeyPath 4Waveform5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN...

Page 411: ...l and horizontal parameters of the waveform You use the knob arrow keys or keypad to change the values of the four scaling softkeys Y Scale changes the vertical scaling of the waveform and Y O set moves the waveform vertically up and down X Scale expands and contracts the waveform horizontally while X Position moves the signal horizontally KeyPath 4Waveform5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Mem...

Page 412: ...rands in a function You can also recall the waveform for future comparison or analysis print it save it to a disk or load it from a disk It takes less time to store and recall data to waveform memories than to store the same data to the disk drive Therefore you may nd it more convenient to use the four waveform memories for storing data temporarily and the disk drive for storing data permanently K...

Page 413: ... are not saved The pixel memory is volatile so turning o the instrument clears the pixel memory However setting the instrument to the default instrument setups does not clear the pixel memory Gray scale persistence information is not saved to a pixel memory You can save several waveforms to the pixel memory and each waveform can have di erent time base and channel scale factors Figure11 13 Saving ...

Page 414: ...al snapshots of the graticule area in the pixel memory without overwriting any previously stored data By using the channel o set to move signals vertically on the display you can create a timing diagram by saving multiple screen snapshots to the pixel memory Then you can save the timing diagram to a disk or you can print it KeyPath 4Waveform5 NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN Memory type NNNNNNN...

Page 415: ...12 Messages ...

Page 416: ...ke to remedy the condition Messages you may see on your instrument A coupled control changed The question mark is a string substitution point that contains the name of a control that changed for example A coupled control changed Time base position In this example the message indicates the horizontal position was changed to account for the bit rate being increased A memory error was detected Servic...

Page 417: ...h the interface between the mainframe and the plug in The indicates which slot has the failure This is a mainframe hardware problem if the slot is empty otherwise there must be a hardware problem in the mainframe or plug in Call Hewlett Packard for service Control setting is unchanged Entry was not completed The Enter key was not pressed after typing in numbers using the keypad before changing men...

Page 418: ...r is cycled and the instrument may not function correctly When Hewlett Packard service replaces the battery a revised boot ROM may be installed Mask test align failed The mask test align algorithm was not able to detect a signal compatible with the installed mask This can occur when there are not enough points on an edge or when the required edges are not present Adjust the timebase to place the r...

Page 419: ...r 1310 nm and 1550 nm are performed on the plug in modules by Hewlett Packard prior to shipping the modules If the plug in module is reprogrammed the factory calibration factors will be erased Plug in is not installed This requested plug in or channel is not installed in the instrument Setup defaulted This normally occurs when you ask for setup to be defaulted At power on the setups are defaulted ...

Page 420: ...ttempt is made to execute a feature that requires an upgrade option and the option is not installed in the instrument The selected point caused an intersection and is not valid When attempting to connect to the newly inserted mask data point the line intersected a line connecting two previously joined points This is illegal and the point is not accepted Waveform data is not valid An attempt was ma...

Page 421: ...13 How the Instrument Works ...

Page 422: ...chapter is an overview of how the instrument works including Sequential sampling basics System architecture plug module hardware components mainframe hardware components probe selection system bandwidth calculation probe types Trigger bandwidth selection 13 2 ...

Page 423: ... an input sampling capacitor As shown in Figure 13 1 this sampling is done by closing a gate for a short amount of time and allowing the signal to charge the shunt capacitor through a source resistance Figure 13 1 Thesamplingcircuit The rate at which this capacitor charges depends on the time constant of the RC network according to the formula Vout Vin 2 1 0 e 0t RC Sampling e ciency is de ned as ...

Page 424: ...s are necessary because the displayed trace is built up from samples taken over multiple repetitions of the waveform Eye diagrams which represent statistical distributions rather than actual waveforms are an exception to this requirement The trigger signal is needed to control the timing of the sampling process In the sequential sampling process the input signal is sampled once per trigger event T...

Page 425: ...Works Basicsof SequentialSampling Figure 13 2 shows the sampled voltage taken over a number of trigger events After the entire screen is lled up the process begins a new sequence Figure13 2 Sequentialsampling process 13 5 ...

Page 426: ... any value between 16 and 4096 points by selecting the Record Length softkey in the Acquisition menu Figure 13 3 shows a waveform acquired with a record length of 64 while Figure 13 4 shows the same waveform acquired with a record length of 2250 In most cases record length should be left on automatic Histogram measurements in particular are susceptible to errors with a non optimum record length Fi...

Page 427: ...using a delay line Use of a delay line compensates for internal delays in the triggering and sampling circuits within the instrument It can be observed from Figure 13 2 that there is an amount of time after the scope has been triggered during which it is not yet ready to accept another trigger even if a valid trigger event occurs This is known as trigger setup and hold time which determines the ma...

Page 428: ...itecture A simpli ed block diagram of the instrument hardware architecture is shown in Figure 13 5 A complete block diagram is presented in the HP 83480A 54750A Service Guide Figure13 5 Hardwareblock diagram 13 8 ...

Page 429: ...g in the A D converter Trigger input The plug in s trigger input passes the trigger signal directly into the mainframe No trigger signal conditioning occurs within the plug in Pulse lter The function of the pulse lter is to transform the low repetition rate trigger pulse from the mainframe into a narrow impulse that drives the sampler The width of this impulse must be as narrow as possible because...

Page 430: ...og pulse at its input and converts it to a 12 bit digital word These 12 bit words are put into a FIFO memory which is then read and processed by the CPU CALtable The CAL table automatically adds the calibration factors to the sampled data The result is referred to as adjusted data and it is sent to the system bus The CAL table increases the throughput of the analyzer because the CPU now reads cali...

Page 431: ...ing waveforms and front panel setups User interface hardware The user interface hardware is the keyboard and the hardware that interfaces the keyboard and knob with the system bus FIFO andHP IB hardware The FIFO is a rst in rst out memory that transfers waveforms through the HP IB bus under hardware control This hardware control is much faster than the software control used by other instruments Th...

Page 432: ...be degrades the circuit under test The new circuit behaves di erently than the circuit without the probe The behavior you see is the behavior of the circuit with the probe 2 The transfer function of the probe is part of the overall measurement system response degrading measurement accuracy Figure13 6 Theprobe isapartof thecircuitundertest 13 12 ...

Page 433: ...ere are two major factors in uencing probe selection 1 the load the probe imposes on the circuit 2 the required bandwidth of the circuit with the probe Probe loading Figure 13 7 shows a simpli ed diagram of the circuit with the probe attached to indicate the principal loading e ects The probe load has both resistive and capacitive components In addition to this the inductance in the probe ground l...

Page 434: ...ce is 9 times the Thevenin output resistance of the circuit under test the amplitude is reduced by about 10 percent Refer to Figure 13 8 The frequency independent amplitude errors and dc o set errors introduced by probe resistive loading are approximately proportional to the ratio of the probe s resistance to ground and the equivalent output resistance of the circuit under test Figure13 8 Reduceda...

Page 435: ... time of transitions The approximate rise time of a simple RC circuit is 2 2 RC Therefore for an output resistance of 100 and a probe tip capacitance of 8 pF the real rise time at the node under test cannot be faster than approximately 1 8 ns although it might be faster without the probe If the output of the circuit under test is current limited as is often the case for CMOS the slew rate is limit...

Page 436: ... test including any parasitic capacitance of PC board traces and so on The ringing frequency of this circuit is F 1 2 p LC If the rise time of the signal is su cient to stimulate this ringing then it can appear as part of the captured signal An approximation of the bandwidth of the signal is Signal Bandwidth 0 35 Signal Rise Time To calculate the ringing frequency assume the probe ground wire has ...

Page 437: ...e time the measured rise time is p 1 ns 2 330 ps 2 1 05 ns Now the error is only 5 percent There are three rules worth memorizing 1 The combined system rise time analyzer and probe should be less than 1 3 the rise time of the measured signal for an error of less than 5 percent or less than 1 7 of the rise time of the measure signal for an error of less than 1 percent 2 Rise time and bandwidth are ...

Page 438: ...l communications analyzer Resistivedividerprobes Resistive divider probes are designed for analyzers with a 50 input impedance The tip of the probe has a 450 or 950 series resistor The cable is designed for a 50 transmission line Because the cable is terminated in 50 at the analyzer input it looks like a purely resistive 50 load when viewed from the tip Therefore the resistive divider is at over a...

Page 439: ...ines The 1 k divider probes are also usually suitable for high speed CMOS circuits If you are interested in troubleshooting CMOS consult the data sheet for the particular CMOS part to make sure that it can drive a 1 k load and to determine what the voltage error would be Active probes An active probe like the HP 54701A has a bu er ampli er at the tip Refer to Figure 13 11 This bu er ampli er drive...

Page 440: ...e loading 0 6 pF and su ciently high resistance 100 k to be useful for both ECL and CMOS circuits and for most analog circuits For the high speed CMOS state machine in the example the HP 54701A active probe o ers the best combination of measurement accuracy with minimal circuit loading Figure13 11 Activeprobe 13 20 ...

Page 441: ... worthwhile to simulate the e ect of the probe using SPICE This discussion assumes a simple resistance as the equivalent circuit for the circuit under test For an actual measurement a more complete model is useful in evaluating the e ects of the probe Some knowledge of the expected signal particularly its rise time or spectral content is also useful in making a probe choice Finally it s important ...

Page 442: ... be selected There is a freerun mode that allows the user to see the signal amplitude before a trigger has been established There is also a high sensitivity setting that reduces trigger hysteresis for low level and low noise signals The DC 2 5 GHz mode is used for the majority of applications because it provides excellent performance for trigger signals up to 2 5 GHz and has the most user selectab...

Page 443: ...00 mV p p sine wave inputs Square wave triggers or other sharp edged transitions will function down to DC but this is not speci ed because it depends on the characteristics of the signal edges If no trigger signal is applied the divider self oscillates providing a freerun trigger for the oscilloscope When a trigger signal is applied the divider will recognize it and provide a stable reference No a...

Page 444: ...2n01 digital signal Therefore the fact that the trigger only recognizes every sixteenth event will not reduce the signi cance of the data However if viewing a signal with a pattern length of modulus 16 where the number of trigger transitions is an integer multiple of 16 the analyzer will only acquire data from certain bits which will reduce the signi cance of the data PRBS signals are of odd lengt...

Page 445: ... trigger input there must be some signi cant separation of the desired and excluded trigger signals This mode if used to separate out individual segments of a continous trigger will result in trigger artifacts Refer to the Trigger Artifacts section later in this chapter for additional information The gate mode allows measurements of signals that previously were di cult or even impossible to view H...

Page 446: ...rdand EnhancedTrigger Modes Figure 13 13 12GHzmode jitterwith200mV p psinewaveinput In gate mode the typical frequency range is 2 to 12 GHz and the sensitivity is reduced requiring a 300 mV p p sine wave input See Figure 13 14 13 26 ...

Page 447: ...ters are key to understanding trigger gating tsetup twidth and tdelay Tsetup the delay between a gate enable positive edge and the rst trigger event that will be recognized This delay is typically 250 ns Twidth the width of the gate enable pulse This should typically be at least 300 ns but may be as long as desired Tdelay the minimum time after the gate is disabled before the trigger transitions a...

Page 448: ...cause the sweep speed is relatively slow the second RF burst can be seen on screen however the trigger point is stable at the beginning of the rst pulse Figure13 15 Gatingapplication Triggerartifacts There are two major types of artifacts that can cause confusion when using the gated trigger Modulus 16 E ect and Gate Enable False Triggers Both are related to the use of a divider IC Modulus16E ect ...

Page 449: ...ggeronsignal withpulsed2GHz RFcontent In Figure 13 17 the carrier modulation is increased to 10 GHz with an expanded time scale At this point the 2 5 GHz trigger mode is not fast enough so the 12 GHz Gate mode is used Figure13 17 12GHz triggeronsignalwith pulsed10GHzRFcontent 13 29 ...

Page 450: ...s this e ect is not important In other cases it may be possible to adjust the signal to be of modulus 16 so that the trigger is stationary GateEnableFalse Triggers In this gating architecture if the trigger input is high when the gate enable is asserted there is a nite chance that a false analyzer trigger will result For example Figure 13 18 shows a 10 Gb s digital eye diagram without using gating...

Page 451: ...ignal is completely asynchronous with the trigger signal the required condition for false triggers occurs frequently The number of false triggers can be reduced by synchronizing the gate enable rising edge with the clock If one could ensure that the gate enable would only be asserted when the trigger input was low no false triggers would occur Figure 13 20 shows the result of triggering the low sp...

Page 452: ...speed pulse generators makes it di cult to ensure that the gate enable edge is stable within a 10 Gb s clock cycle It may be possible in some experimental setups to generate coherent and stable gate enable signals more directly from the trigger signal and achieve better results While the 12 GHz Gate mode allows triggering on complex and high speed signals care must be taken during experimental set...

Page 453: ...Index ...

Page 454: ...6 accuracy and resolution 9 4 acquisition channel 9 5 menu 10 3 6 status 1 14 active probes 13 19 ac Vrms 7 15 A D converter 13 10 add math softkey 10 48 Add to memory waveform softkey 11 98 algorithm measurement 5 5 7 8 10 8 threshold detection 10 10 aliasing FFT 10 35 Align Mode mask test softkey 6 22 altitude 3 6 AMI alternate mask inversion 10 16 amplitude display 1 10 measurement 10 11 measur...

Page 455: ...se voltage value 10 12 base waveform measurement 7 8 Best acquisition softkey 10 5 binary le format 11 14 bit period 5 7 5 30 units 6 45 10 54 bit rate 5 30 masks 5 26 Bit rate eye softkey 5 7 Bit rate mask softkey 5 30 Bit Rate time base softkey 6 45 10 54 blue labeled functions 5 9 building a histogram 7 6 9 building the database 10 37 bw limit math softkey 10 50 C cables 9 14 calculating thresh...

Page 456: ... 6 43 10 7 channel to channel measurement 9 5 characteristics performance 3 2 circuit measurement 1 3 Clear Display control key 2 3 Clear memory waveform softkey 11 98 clock signal 5 29 5 39 Clr meas softkey 1 12 CMI coded mark inversion 10 16 Color display softkey 11 38 color graded database 7 8 7 16 display 5 11 6 6 10 6 10 37 histogram mode 5 3 Color Grade de ne measure softkey 10 16 Color grad...

Page 457: ... 12 2 6 custom masks 6 19 custom measurements 11 56 D Dark Cal eye softkey 5 11 Dark cal measure eye softkey 6 33 data acquisition 2 7 8 10 37 10 45 collection 7 5 display 11 24 record 7 4 database memory area 10 37 Data setup disk softkey 11 76 date and time 11 82 Date utility softkey 11 82 DC 100 MHz softkey 6 53 10 64 DC 100 MHz trigger softkey 13 22 DC 2 5 GHz softkey 6 53 10 64 DC 2 5 GHz tri...

Page 458: ...circuit measurement 1 3 directory disk softkey 11 4 disk drive 13 11 disk le extensions 11 8 Disk limit test softkey 11 51 11 54 55 Disk mask test softkey 6 26 29 Disk menu 11 3 23 Disk setup print softkey 11 75 display 1 11 13 11 Display display softkey 11 34 Display eye softkey 5 7 Display FFT softkey 10 23 Display mask softkey 5 29 Display math softkey 10 51 Display menu 11 24 41 display visual...

Page 459: ...y state 5 50 ESD reducing damage caused by ESD xviii static safe work station xvi External Scale trigger softkey 6 52 10 62 external trigger 1 10 extinction ratio 5 10 calibration routine 6 33 Extinction ratio measure eye softkey 6 32 Ext ratio eye softkey 5 11 eye mode 5 47 parameter measurement 5 46 eye diagram 5 38 7 4 gure of merit 6 41 horizontal opening measure 6 38 measurement 5 3 24 vertic...

Page 460: ...y 11 45 Failures limit test softkey 11 48 failure test results summary 11 50 Fail When limit test softkey 11 45 falling edge determination 7 11 measurement 8 4 fall time 5 23 measurement 7 7 7 17 8 4 Fall Time softkey 8 7 fast display softkey 11 28 FFT aliasing 10 35 amplitude measurements 10 32 automatic measurements 10 28 basics 10 28 computing dBm 10 33 computing dBV 10 34 frequency accuracy 10...

Page 461: ... 11 10 Format disk softkey 11 14 Format eye softkey 5 11 5 16 Format setup print softkey 11 73 Form Feed setup print softkey 11 73 frame display box 11 81 memory declassifying 11 83 screen mode 11 31 frame display softkey 11 32 freerun threshold 1 14 Free Run trigger softkey 6 51 10 61 Freq Domain menu 8 14 18 frequency accuracy FFT 10 31 display 1 10 measurement 7 4 7 7 7 10 8 3 measurements FFT ...

Page 462: ...d display softkey 11 31 grid screen mode 11 31 H hardware architecture 13 8 hardware components mainframe 13 10 11 plug in module 13 9 header information 11 15 11 19 Help menu 2 5 Help system key 2 5 high resolution display softkey 11 30 high speed data port 1 17 histogram 1 13 6 6 7 4 7 6 9 10 37 color graded 5 3 7 8 7 16 horizontal 6 36 horizontal markers 10 42 statistics 10 39 vertical 6 36 ver...

Page 463: ...Hysteresis trigger softkey 6 53 10 63 I IF amp 13 9 Ignore limit test softkey 11 46 incomplete transitions 7 12 increasing measurement accuracy 9 3 8 9 19 indicator lights 1 14 in nite display softkey 11 26 in nite persistence 5 50 11 26 input voltage time changes 9 14 insertion loss testing xxv Insert mask test softkey 6 13 instrument display 1 11 messages 12 2 overview 1 3 13 2 integrate math so...

Page 464: ... test 1 13 11 44 summary 11 50 Limit Test Menu 11 42 55 line input 1 16 on o 1 16 select 1 16 Linear O set histogram softkey 10 43 Linear Scale histogram softkey 10 43 load disk softkey 11 6 Local control key 2 6 Local Lockout command 2 6 locating crossing points 7 9 Location display softkey 11 33 logic level 5 10 5 21 5 23 6 32 Log O set histogram softkey 10 43 Log Scale histogram softkey 10 43 l...

Page 465: ...mpliance 5 34 value 5 36 Margin mask test softkey 6 18 Margin softkey 5 34 marker 9 5 color 11 56 hints 11 63 lines 5 10 menu overview 11 56 position readout 11 60 threshold setting 10 11 to show top base setting 10 13 voltage measurement 11 59 Marker de ne measure key 10 13 Marker Menu 11 56 63 Marker Results display 1 12 mask custom 6 19 failure 5 36 le format 11 14 xed voltage 6 4 generating 5 ...

Page 466: ...stogram softkey 8 20 mean stddev de ne measure softkey 10 20 Meas Complete de ne measure softkey 10 18 Meas eye eye key 5 9 Meas Not Found limit test softkey 11 46 Measure Eye menu 6 30 42 measurement algorithm 5 5 7 8 10 8 automatic 1 12 8 3 22 9 4 10 14 average frequency 8 3 capabilities 1 3 channel to channel 9 5 considerations 7 20 increasing accuracy 9 3 8 9 19 parameters 7 3 repeatability on...

Page 467: ...tion 9 5 minimum persistence 6 7 min math softkey 10 49 min max de ne measure softkey 10 21 0Width measurement 7 18 8 4 0width softkey 8 6 MMS mainframe 5 43 Mode histogram softkey 10 40 Mode limit test softkey 11 48 Mode mask test softkey 6 23 Modify Label display softkey 11 36 Move mask test softkey 6 13 Move Polygon mask test softkey 6 13 multiply math softkey 10 48 N narrow pulse response 9 16...

Page 468: ...al accessories 1 5 options 1 5 output CAL signal 11 88 Overshoot 7 16 overshoot measurement 8 4 Overshoot softkey 8 7 overview of the front panel 1 9 of the instrument 1 3 of the rear panel 1 15 P packaging materials xiii Page Length setup print softkey 11 73 parallel printer port 1 17 parameter measurement 7 3 Pass limit test softkey 11 46 pattern generator eyeline 5 43 peak histogram softkey 8 2...

Page 469: ...ker softkey 11 60 Position mask softkey 5 30 position setting 1 12 Position time base softkey 6 46 10 55 power measurement 7 14 16 power statistics 11 81 PRBS pattern 5 47 presetting parameters FFT 10 35 Preshoot 7 16 preshoot measurement 8 4 Preshoot softkey 8 8 Printer limit test softkey 11 51 11 54 Printer mask test softkey 6 26 6 28 Print format setup print softkey 11 72 printing problem repor...

Page 470: ...eyeline connections 5 43 features 1 15 Recall setup softkey 11 66 record length 13 5 automatic 10 6 manual 10 6 Record length acquisition softkey 10 6 reduction of noise 5 40 reference location 1 12 Reference time base softkey 6 47 10 56 reference waveform 6 5 tolerance 6 8 Refresh disk softkey 11 5 regulatory information ii remote control 2 6 repair information xii repetitive signal 1 10 resistiv...

Page 471: ... Save setup softkey 11 65 Save waveform softkey 11 96 Scale eye softkey 5 7 Scale Mask mask test softkey 6 19 Scale mask softkey 5 29 5 30 Scale math softkey 10 51 Scale Mode histogram softkey 10 45 scale setting 1 12 Scale Source histogram softkey 10 41 Scale source mask test softkey 6 19 Scale time base softkey 6 46 10 55 Scale Type histogram softkey 10 43 screen mode 11 31 Screen setup print so...

Page 472: ...tware eyeline installation 5 46 Source eye softkey 5 6 Source FFT softkey 10 23 Source freq domain softkey 8 17 Source marker softkey 11 60 Source mask softkey 5 29 Source mask test softkey 6 8 Source trigger softkey 6 51 10 61 speci cations 3 3 7 standard deviation 9 5 10 18 mask 5 26 5 32 6 4 waveform de nitions 7 14 20 8 4 Standard de ne measure softkey 10 12 Standard Mask mask test softkey 6 9...

Page 473: ...ition 6 46 10 55 speed 6 46 10 55 Sweep trigger softkey 6 51 10 60 system architecture 13 8 bandwidth 13 17 setup 5 4 System Con guration utility softkey 11 80 system rmware updating 11 84 T TDR TDT marker softkey 11 62 temperature 3 6 test capabilities 1 3 Test limit test softkey 11 44 Test mask test softkey 6 7 test results failure summary 11 50 text verbose disk softkey 11 15 text verbose le fo...

Page 474: ...ime interval measuring 9 3 9 6 9 9 time location variance of crossing points 6 39 time units 5 30 Time utility softkey 11 82 timing diagram 11 98 timing measurement 7 11 7 17 10 9 de nitions 7 14 20 8 4 histogram 10 36 Tmax general meas softkey 8 12 Tmax measurement 7 7 Tmin general meas softkey 8 12 Tmin measurement 7 7 To File disk softkey 11 22 To memory disk softkey 11 23 To memory waveform so...

Page 475: ...ent 7 7 two channel measurement 9 3 Type disk softkey 11 11 Type display softkey 11 31 typeface conventions x U 1 time measurement 8 3 1time measurement 7 19 1time softkey 8 5 1X mask test softkey 6 8 6 20 1Y mask test softkey 6 8 Undo Autoscale softkey 1 10 Units eye softkey 5 7 Units mask softkey 5 30 Units mask test softkey 6 8 Units time base softkey 6 45 10 54 Update System Firmware utility s...

Page 476: ...aveform conformance to the mask 5 34 versus math softkey 10 48 vertical axis 10 45 channel errors 9 9 dc errors 9 9 display 1 10 10 40 histogram 6 32 6 36 10 36 marker 10 42 11 59 quantization 9 13 reference thresholds 10 11 resolution 11 30 scale 5 7 5 29 scaling factors 11 55 tolerance of reference waveform 6 8 Vertical math softkey 10 52 vibration 3 6 video RAM 13 11 viewing statistics 9 5 View...

Page 477: ...play 1 12 markers 11 59 measurement 9 19 measurement process 7 4 13 measurement repeatability 10 4 memory 6 29 11 23 menu overview 11 93 noise measurement 10 36 noise reduction 10 4 non symmetrical 8 3 period measurement 7 13 position 5 5 5 28 record display 1 13 resolution improvement 10 4 tolerance 6 8 Waveform disk softkey 11 11 Waveform display softkey 11 33 Waveform histogram softkey 10 40 wa...

Page 478: ...Position marker softkey 11 58 X1 Position mask test softkey 6 19 X1 Y1 Source marker softkey 11 58 X2 Position marker softkey 11 58 X2 Y2 Source marker softkey 11 58 X and Y Position histogram softkey 10 42 X marker 5 10 X mask test softkey 6 12 X Position marker softkey 11 60 X Source marker softkey 11 60 Y Y1 marker scaling 6 19 Y1 Position marker softkey 11 59 Y2 Position marker softkey 11 59 Y...

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