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Tektronix TDS744A Manual

1. Original Scale Scaled Vertically Scaled Horizontally Figure 3 5 Scaling and Positioning Check the Vertical Readout at the bottom left part of the display to read the volts division setting for each displayed channel the selected channel is in inverse video See Figure 3 6 The TDS Oscilloscope permits you to change vertical scale and position quickly from the front panel using dedicated control knobs To change the vertical scale and position 1 Turn the vertical SCALE knob Note only the scale of the selected wave form changes TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms As you turn the vertical SCALE knob clockwise the value decreases resulting in higher resolution because you see a smaller part of the wave form As you turn it counterclockwise the scale increases allowing you to see more of the waveform but with lower resolution 2 Turn the vertical POSITION knob Again note that only the selected waveform changes position 3 To make positioning faster press the SHIFT button When the light above the SHIFT button is on and the display says Coarse Knobs in the upper right corner the POSITION knob positions waveforms more quickly The POSITION knob simply adds screen divisions to the reference point of the selected waveform Adding divisions moves the waveform up and subtracting them moves the waveform down You
2. Figure 3 82 Comparing a Waveform to a Limit Template TDS 684A TDS 744A amp TDS 784A User Manual 3 137 Using Features for Advanced Applications To use limit testing you must do four tasks m Create the limit test template from a waveform m Specify the channel to compare to the template m Specify the action to take if incoming waveform data exceeds the set limits m Turn limit testing on so that the parameters you have specified will take effect To do the tasks just listed do the following procedures To Create Limit Test To use an incoming or stored waveform to create the limit test template first you Template select a source and specify a template destination Then you create the template envelope by specifying the amount of variation from template you will tolerate To do these tasks perform the following steps 1 Press SHIFT ACQUIRE MENU to bring up the Acquire menu 2 Press Create Limit Test Template main gt Template Source side gt Ch1 Ch2 Math1 Math2 Math3 Ref1 Ref2 Ref3 or Ref4 side See Figure 3 83 NOTE The template will be smoother if you acquire the template waveform using Average acquisition mode If you are unsure how to select Average see Selecting an Acquisition Mode on page 3 23 3 Once you have selected a source select a destination for the template press Template Destination side gt Ref1 Ref2 Ref3 or Ref4 3
3. 110 1 1 1 1 Figure 3 87 Define FFT Waveform Menu 7 Press Set FFT Vert Scale to side repeatedly to choose from the following vertical scale types dBV RMS Magnitude is displayed using log scale expressed in dB relative to 1 Vpms where 0 dB 1 Vrms Linear RMS Magnitude is displayed using voltage as the scale Phase deg Phase is displayed using degrees as the scale where degrees wrap from 180 to 180 Phase rad Phase is displayed using radians as the scale where radians wrap from T to 7 The topic Considerations for Phase Displays on page 3 156 provides in depth information on setup for phase displays 8 Press Set FFT Window to side repeatedly to choose from the following window types Rectangular Best type of window for resolving frequencies that are very close to the same value but worst for accurately measuring the amplitude of those frequencies Best type for measuring the frequency spectrum of nonrepetitive signals and measuring frequency components near DC TDS 684A TDS 744A amp TDS 784A User Manual 3 147 Using Features for Advanced Applications 10 11 12 Hamming Very good window for resolving frequencies that are very close to the same value with somewhat improved amplitude accuracy over the rectangular window Hanning Very good window for measuring amplitude accuracy but degraded for resolving freque
4. Figure 2 1 Connecting a Probe for the Examples P6245 shown TDS 684A TDS 744A amp TDS 784A User Manual 2 9 Tutorial NOTE See Appendix A Options and Accessories for optional probes you can order and use with this product Reset the Oscilloscope Do the following steps to reset the oscilloscope to a known factory default state before doing the examples You can reset the oscilloscope anytime you begin a new task and need to start fresh with known default settings 1 Press the save recall SETUP button to display the Setup menu See Figure 2 2 SAVE RECALL WAVEFORM STATUS APPLICATION ET MENU _ ACQUIRE MENU MEASURE HARDCOPY RUN STOP Cc UTILITY SHIET CURSOR DISPLAY SETUP SETUP Buton E i HE 1S A VERTICAL A HORIZONTAL Figure 2 2 SETUP Button Location The oscilloscope displays main menus along the bottom of the screen Figure 2 3 shows the Setup main menu OK Confirm Factory Init Menu Item and Button Recall Factory Setup Menu Item and Button Figure 2 3 The Setup Menu 2 Press the button directly below the Recall Factory Setup menu item 2 10 TDS 684A TDS 744A amp TDS 784A User Manual Tutorial The display shows side menus along the right side of the screen The buttons to select these side menu items are to the right of the side menu Because
5. Slolololoj Waveform Drawn on CRT Acquisition 1 2 3 Sgt aries ga Envelope AS Finds highest and Uses Peak Detect Mode for Each Acquisition lowest record points over ian 2 many acquisitions Use to reveal variations in the signal across time CIOJO C O Calculates average value for Uses Sample Mode for Each Acquisition each record point over eee sh many acquisitions Use to reduce apparent noise in a repetitive signal yee Figure 3 13 How the Acquisition Modes Work TDS 684A TDS 744A amp TDS 784A User Manual CLCIJO C O 3 21 Acquiring and Displaying Waveforms 3 22 A Peak Detect Mode TDS 700A models only Peak Detect mode alternates between saving the highest sample in one acquisition interval and lowest sample in the next acquisition interval Peak Detect mode only works with real time noninter polated sampling If you set the time base so fast that it requires real time interpolation or equivalent time sampling the mode automatically changes from Peak Detect to Sample although
6. Over 14 8 Over 34 8 High 512m Low SmvV Max 536m Min 16mVv Ampl 504mvV Pk Pk 552m i Mean 255 6m cycMean 252 0mv RMS 359 2mv CYCRMS 356 4mV hv Area 1 27528mVs CycArea 251 80yVs Brstwd 4 490ms ant Rise BMS Fall 1 BUS Duty 50 0 Duty 50 0 elect r igh Low Remove Gating Reference Measrmnt Setup Snapshot forech Measrmnt OFF Histogram Levels Snapshot Haa Figure 3 57 Snapshot Menu and Readout Consider the following rules when taking a snapshot Be sure to display the waveform properly before taking a snapshot Snapshot does not warn you if a waveform is improperly scaled clipped low signal amplitude low resolution etc To vary the source for taking a snapshot simply select another channel math or ref memory waveform and then execute snapshot again Note that a snapshot is taken on a single waveform acquisition or acquisi tion sequence The measurements in the snapshot display are not continu ously updated Be careful when taking automatic measurements on noisy signals You might measure the frequency of the noise and not the desired waveform Note that pushing any button in the main menu except for Snapshot or any front panel button that displays a new menu removes the snapshot from display Use High Low Setup page 3 92 Reference Levels page 3 93 and Gated Measurements
7. 0 eee ee eee wees 2 23 Figure 2 18 Save Recall Setup Menu ccccececceees 2 25 Figure 3 1 How Probe Compensation Affects Signals 3 4 Figure 3 2 P6139A Probe Adjustment cece eeeeee 3 4 Figure 3 3 The Channel Readout ccceccecscceces 3 8 Figure 3 4 Waveform Selection Priority ceeeeeeee 3 9 Figure 3 5 Scaling and Positioning cceceecseceees 3 10 Figure 3 6 Vertical Readouts and Channel Menu 3 11 Figure 3 7 Record View and Time Base Readouts 3 13 Figure 3 8 Horizontal Controls ccccece cscs cceees 3 14 Figure 3 9 Acquisition Input Analog Signal Sample and DigitiZe 5 525 Fics sie e esis E sive EE bie sue oeis oa ES 3 17 Figure 3 10 Several Points May be Acquired for Each Point Used sco ise 5255 5585 sli os co NN Te seed Ta eas eee Sas ees 3 17 TDS 684A TDS 744A amp TDS 784A User Manual iii Table of Contents Figure 3 11 Figure 3 12 Figure 3 13 Figure 3 14 Figure 3 15 Figure 3 16 Figure 3 17 Figure 3 18 Figure 3 19 Figure 3 20 Figure 3 21 Figure 3 22 Figure 3 23 Figure 3 24 Figure 3 25 Mode Figure 3 26 Mode Figure 3 27 Figure 3 28 Figure 3 29 Figure 3 30 Figure 3 31 Figure 3 32 Figure 3 33 Figure 3 34 Real Time Sampling cc cceccecscceces 3 17 Equivalent Time Sampling ceeeeeees 3 18 How the Acquisition
8. gt Main Trigger P oint i Main Trigger Source o l Delayed Trigger Source ae aaa en Start P osttrigger Acquisition ying First Trigger After Delay Delayed Triggerable By Events Time Main Trigger Point k dei Trigger Waveform Record gt Main Trigger Source l Delayed NINN Trigger 7 Source Me XR v 4 Waiting for nth Event H Time Delay gt Start Posttrigger Acquisition Where n 4 From Delay Trig Menu Figure 3 49 How the Delayed Triggers Work 3 82 TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms NOTE Due to hardware limitations the delayed time base cannot be made triggerable when the main trigger type is Logic any class or when the main trigger type is Pulse with Runt or Slew Rate classes selected For these settings the oscilloscope will force the delayed time base to be in Runs After mode To Run After Delay You use the Horizontal menu to select and define either delayed runs after main or delayed triggerable Delayed triggerable however requires further selections in the Delayed Trigger menu Do the following steps to set the delayed time base to run immediately after delay 1 Press HORIZONTAL MENU gt Time Base main gt Delayed Only side gt Delayed Runs After Main side 2 Use the general purpose knob or the keypad to set the delay time If you press Intensified side you display an intensified
9. Figure 3 64 Re use Probe Calibration Data Menu TDS 684A TDS 744A amp TDS 784A User Manual Measuring Waveforms Table 3 10 Probe Cal Status If the Re use Probe Calibration data menu is displayed you can choose one of the following options m Press OK Use Existing Data side to use the Probe Cal data last stored to compensate the probe m Press OK Erase Probe Cal Data side to erase the Probe Cal data last stored and use the probe uncompensated m Press CLEAR MENU on the front panel to retain the Probe Cal data last stored and use the probe uncompensated NOTE If the Re use Probe Calibration data menu is displayed do not select OK Use Existing Data if the probe currently installed is not of the same impedance stored for the Probe Cal For example if the last Probe Cal stored for a channel was done with a passive 50 Q probe installed do not install a passive 1 MQ probe and select OK Use Existing Data if the menu appears If you do so most of any signal you attempt to measure will not be coupled to the input channel because of the probe to oscilloscope impedance mismatch Table 3 10 shows the action the oscilloscope takes based on the probe connected and user operation performed Type Probe Connected Probe Cald User Action Simple Interface TEKPROBE Interface No Doesn t Matter Initialized Initialized Yes Power off Initialized Initialized probe data is retained probe data is retai
10. 3 48 FastFrame Operating Characteristics Consider the following operating character istics when using FastFrame Envelope Average and Hi Res form the envelope or average following the last frame of the concatenated record For example if Average or Hi Res acquisition modes are selected and the frame count is 10 segments 1 through 10 will show Sample or Hi Res frames and frame 11 will show the average of frames 1 through 10 If there is not room for one additional frame the envelope or average of the frames replaces the display of the last acquired frame Average and envelope counts have no affect in FastFrame You can press RUN STOP to terminate a FastFrame sequence If any frames were acquired they are displayed If no frames were acquired the previous FastFrame waveform is displayed Because FastFrame waveforms contain many triggers trigger position indicators are removed from both the waveform and the record view when the selected channel reference or math waveform is a FastFrame waveform In Equivalent Time the oscilloscope ignores FastFrame mode Because FastFrame introduces additional processing time into the operation cycle of acquire process and display its best to use Single Sequence Acquisition see Acquire menu Stop After menu With Single Sequence selected you will see the current acquisition sequence otherwise the display lags the current sequence by one sequence You can also see the current sequen
11. 1 TDS 684A Press DISPLAY Readout Options main TDS 700A Models Press DISPLAY Mode main gt Normal pop up gt Format RO main TDS 684A TDS 744A amp TDS 784A User Manual 3 29 Acquiring and Displaying Waveforms 3 30 Trigger P oint Indicator Trigger Bar Long Style Or Trigger Bar Short Style 2 Toggle Display T Trigger Point side to select whether or not to display T indicating the trigger point You can select ON or OFF The trigger point indicates the position of the trigger in the waveform record Press Trigger Bar Style side to select either the short or the long trigger bar or to turn the trigger bar off See Figure 3 18 Note that both styles are shown for illustrating purposes but you can only display one style at a time The trigger bar is only displayed if the trigger source is an active displayed waveform Also two trigger bars are displayed when delay triggerable acquisitions are displayed one for the main and one for the delayed timebase The trigger bar is a visual indicator of the trigger level Sometimes especially when using the hardcopy feature you may want to display the current date and time on screen To find more information displaying and setting date and time see Date Time Stamp the Hardcopy on page 3 123 Press Display Date Time side to turn it on or off Push Clear Menu to see the current date and time Tek Run 50 0kS 5 Sam
12. 2 0 45 3 46 Triggering Concepts 0 ie E A E E o E A RE E E 3 49 Triggering from the Front Panel 0 0 0 eee eee eee 3 53 Triggering on a Waveform Edge 0 0 c eee eee ee eee 3 57 Triggering Based on Logic 0 cee eee eee ee 3 60 Triggering on Pulses ioiaren ere bhatt tb helt ek foes Geek eela 3 70 Delayed Trig serine iie sual e ately eae rane sete aaa 3 80 Taking Automated Measurements 0 0 e eee eee eee 3 87 Taking Cursor Measurements 0 0 cece eee eee eee eee 3 97 Taking Graticule Measurements 0 0 0 e eee eee eee ee 3 101 Optimizing Measurement Accuracy SPC and Probe Cal 3 102 Saving and Recalling Setups 2 0 0 0 eee cee eee 3 111 Saving and Recalling Waveforms 0 0 c sees ee eee eee 3 114 Managing the File System 0 0 0 eee cee eee eee 3 117 Printing a Hardcopy 0 0 eee eere 3 120 Communicating with Remote Instruments 0 3 128 Displaying Status 0 iee a ei iii cece ee eee eee 3 133 Displaying Help rere tac ci Cae te eaten tee ha sheets aut awe 3 135 Limite Testing ct cst a ie e be hon e Ba dow dence Gaeta ages 3 137 Waveform Math io cae pda tages c cee bein 8A opts ethene tae do 3 142 Fast Fourier Transforms 0 0 cece eee eee eee 3 144 Waveform Differentiation 0 0 0 0 eee eee eee ees 3 161 Waveform Integration 0 0 eee eee
13. A TDS 700A model oscilloscope the TDS 684A uses only real time sampling uses equivalent time sampling to extend its sample rate over its real time maximum sampling rate but only under two conditions m You must have turned equivalent time on in the Acquisition menu m You must have set the oscilloscope to a sampling rate that is too fast to allow it to get enough samples with which to create a waveform record using real time sampling If both conditions are the case the oscilloscope takes a few samples with each trigger event and eventually obtains enough samples to construct a waveform record In short the oscilloscope makes multiple acquisitions of a repetitive waveform to obtain the sample density required for a waveform record See Figure 3 12 By doing so the oscilloscope lets you accurately acquire signals with frequencies much higher than its maximum real time bandwidth would allow Equivalent time sampling should only be used on repetitive signals Record Points e se T Ist Acquisition Cycle Soo T So 2nd Acquisition Cycle Ilo Jl 3rd Acquisition Cycle JIO SI nth Acquisition Cycle S a Figure 3 12 Equivalent Time Sampling The type of equivalent time sampling the oscilloscope uses is called random equivalent time sampling Although it takes the samples sequentially in time it takes them randomly with respect to the trigger Random sampling occurs because the oscilloscope sample clock runs asynchronously with re
14. Delayed Runs 16 50n5 After Main Time Base Readout To Change Horizontal Scale and Position ce og ae _ Delayed chi 200m Triggerable see Delayed Trig Menu Trigger osition 50 lolala Figure 3 7 Record View and Time Base Readouts The TDS Oscilloscope provides control of horizontal position and scale using either the horizontal front panel knobs By changing the horizontal scale you can move the waveform right or left to see different portions of the waveform That is particularly useful when you are using larger record sizes and cannot view the entire waveform on one screen TDS 684A TDS 744A amp TDS 784A User Manual 3 13 Acquiring and Displaying Waveforms 3 14 To Change Horizontal Parameters To change the horizontal scale and position 1 Turn the horizontal POSITION and horizontal SCALE knobs See Figure 3 8 2 If you want the POSITION knob to move faster press the SHIFT button When the light above the shift button is on and the display says Coarse Knobs in the upper right corner the POSITION knob positions waveforms more quickly A HORIZONTAL lt JpositionD gt O HORIZONTAL MENU C SCALE gt Figure 3 8 Horizontal Controls When you select a channel the horizontal SCALE knob scales all channel waveforms displayed at the same time If you select a math or reference waveform t
15. Next Acquired Waveform Record v v 4 Dead Time Dead Time Dead Time Waveform Waveform Waveform Memory Memory Memory Display Updated Display Updated Display InstaVu Mode Ist Set of Acquired Next Set of Acquired Next Set of Acquired Waveform Records Waveform Records Waveform Records A AC A 1 AM 0 N Waveform Memory BitMap Variable Persistence Display Figure 3 26 Normal DSO Acquisition and Display Mode Versus InstaVu Mode 3 44 Waveform Memory Bit Map Updated Variable Persistence Display Waveform Memory Bit Map Updated Variable Persistence Display TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms Tek Run spose Sample BEAY Berisience 10 00 5 Instavu Style JIL Vectors Dots Infinite Persistence Siua gg lt M Toons Chis zgon persistance l 10 00 a a imensty P Sou 11 1 1 1 1 1 LOJO C C C Figure 3 27 InstaVu Display To Set the InstaVu Style To change the InstaVu display style do the following steps 1 Press DISPLAY Mode main gt InstaVu pop up gt Style main 2 Select between Vectors and Dots in the side menu Dots display is the factory default setting 3 Select between In
16. Using Features for Advanced Applications Offset Position and Scale The following topics contain information to help you display your FFT properly Adjust for a Non Clipped Display To properly display your FFT waveform scale the source waveform so it is not clipped m You should scale and position the source waveform so it is contained on screen Off screen waveforms may be clipped resulting in errors in the FFT waveform Alternately to get maximum vertical resolution you can display source waveforms with amplitudes up to two divisions greater than that of the screen If you do turn on Pk Pk in the measurement menu and monitor the source waveform for clipping m Use vertical position and vertical offset to position your source waveform As long as the source waveform is not clipped its vertical position and vertical offset will not affect your FFT waveform except at DC DC correction is discussed below Adjust Offset and Position to Zero for DC Correction Normally the output of a standard FFT computation yields a DC value that is twice as large as it should be with respect to the other frequencies Also the selection of window type introduces errors in the DC value of an FFT The displayed output of the FFT on TDS oscilloscopes is corrected for these errors to show the true value for the DC component of the input signal The Position and Offset must be set to zero for the source waveform in the Vertical menu When meas
17. 2 A6303 Current Probe Used in the AM 503S Opt 03 TDS 684A TDS 744A amp TDS 784A User Manual Table of Contents List of Tables Table 1 1 Key Features of the TDS Oscilloscopes Table 1 2 Fuse and Fuse Cap Part Numbers Table 3 1 Autoset Defaults cece eee cee Table 3 2 How Interleaving Affects Sample Rate Table 3 3 Additional Resolution Bits Table 3 4 TDS 744A Sampling Mode Selection When Fit to Screen is Off ccecceee Table 3 5 TDS 784A Sampling Mode Selection When Fit to Screen is Off ccccceee Table 3 6 XY Format Pairs eee eee Table 3 7 Pattern and State Logic Table 3 8 Pulse Trigger Definitions Table 3 9 Measurement Definitions Table 3 10 Probe Cal Status 000s Table A 1 Options ccc ccc cece ees ecscnes Table A 2 Standard Accessories 08 Table A 3 Optional Accessories ee005 Table A 4 Accessory Software ceeceeees Table D 1 Factory Initialization Defaults TDS 684A TDS 744A amp TDS 784A User Manual vii Table of Contents viii TDS 684A TDS 744A amp TDS 784A User Manual ae e General Safety Summary Injury Precautions Use Proper Power Cord Avoid Electric Overload Ground the Product Do Not Operate Without Covers Use Proper Fuse Do Not Operate in Wet Damp Conditions
18. 62 3 68 3 86 Slew Rate 3 72 Glossary 9 Glossary 10 Slew rate 3 71 Slope 3 53 Source 3 50 State 3 61 3 67 3 86 Status Lights 3 55 Types 3 57 3 86 Video 3 51 Width 3 71 3 76 Trigger Bar 2 6 3 48 Trigger Bar Style Display menu 3 30 Trigger if Faster Than Main Trigger menu 3 79 Trigger if Slower Than Main Trigger menu 3 79 Trigger Level Bar Readout 3 29 3 48 Trigger MAIN LEVEL knob 2 14 3 53 3 54 TRIGGER MENU button 3 57 3 58 3 64 3 67 3 68 3 72 3 74 3 77 Trigger Point Readout 3 29 3 48 Trigger Position Horizontal menu 3 15 Trigger Status Lights 3 55 Trigger When Main Trigger menu 3 66 3 68 3 78 Trigger delayed How to set up 3 83 Trigger edge How to set up 3 58 3 86 Trigger glitch How to set up 3 72 3 86 Trigger runt How to set up 3 74 3 86 Trigger slew rate How to set up 3 77 3 86 Trigger Status menu 3 133 Trigger width How to set up 3 76 3 86 Triggering on Waveforms 3 49 Triggering Auto mode Incompatible with InstaVu 3 45 True for less than Main Trigger menu 3 66 True for more than Main Trigger menu 3 66 Type Logic Main Trigger menu Logic 3 64 3 67 3 68 Pulse 3 77 Type Pulse Main Trigger menu 3 72 Index 13 Index Type Main Trigger menu 3 57 3 58 3 76 Pulse 3 74 U Undershoot Glossary 7 user Saved setup status 3 111 UTILITY button 3 103 3 122 3 131 Utility Menu OK Era
19. CO Name f OK BCDEFGHIJ KLMNOPQRSTUVWRY20123456789 2_ amp Accept Enter Char gt EE Delete Clear Oooo oloo Figure 3 69 File System Labeling Menu To Copy To copy a file or directory turn the general purpose knob until it scrolls the cursor over the name of the file to copy Then press the side menu Copy button The file menu will reappear with the names of directories to copy to Select a directory and press the side menu button labelled Copy lt name gt to Selected Directory To copy all files select the entry The oscilloscope copies all directories recursively That means it copies both the directories and all their contents To Print To print a file turn the general purpose knob until it scrolls the cursor over the name of the file to print Then press the side menu Print button The Print to side menu should appear Select the port to print to from GPIB RS 232 or Centronics Then the oscilloscope will send the file in its raw form out the port The device printer receiving the file must be capable or printing the particular file format To Create a Directory To create a new directory press the side menu Create Directory button TDS 684A TDS 744A amp TDS 784A User Manual 3 119 Saving Waveforms and Setups To Set Confirm Delete To Set Overwrite Lock To Format To Find More Information Printing a
20. Changed by Factory Init to Horizontal main time division 500 us Horizontal main trigger position 50 Horizontal position 50 Horizontal record length 500 points 10 divs Horizontal time base Main only Limit template V Limit 40 mdiv H Limit 40 mdiv Limit template destination Refl Limit template source Chl Limit test sources Chl compared to Ref all others compared to none Limit Testing Off Limit Testing hardcopy if condition met Off Limit Testing ring bell if condition met Off Logic pattern trigger Ch4 input X don t care Logic state trigger Ch4 input Rising edge Logic trigger class Pattern Logic trigger input pattern and state Channel 1 H high Channels 2 amp 3 X don t care Logic trigger logic AND pattern and state Logic trigger pattern time qualification Lower limit 5 ns Upper limit 5 ns Logic trigger S etup Hold times Setup 3 ns Hold 2 ns Logic trigger sources and levels Setup Hold Data Source Channel 1 1 4 V Clock Source Channel 2 1 4 V Source levels are clipped to 1 2 V atthe default volts division setting established by Factory Init Clock Edge Rising Logic trigger threshold all channels pattern state and S etup Hold TDS 684A TDS 744A amp TDS 784A User Manual 1 4 V clipped to 1 2 V at the default volts division setting D 3 Appendix D Factory Initialization Settings Table D 1 Factory Initialization
21. Color Matches Contents Color Ref Reset to Factory Color Restore Colors oss Co Co Co Co Co Figure 3 21 Display Menu Map Reference Colors To define what color to show where a waveform crosses another waveform 1 Press the Options main menu item 2 Toggle Collision Contrast to ON in the side menu to mark collision zones with a special color To restore colors to their factory default settings 1 Press the main menu Restore Colors item See Figure 3 22 2 Select the object s you want to restore by pressing Reset Current Palette To Factory Reset All Palettes To Factory or Reset All Mappings To Factory in the side menu TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms Tek Run 100kS 5 Sample Restore Colors Reset Current Palette to Factory Reset All Palettes to Factory Reset All Mappings to Factory s00mv C M 500s Chii 270mv Eo Palette Change ap ap x Restore Settings Math Reference Options H lt Color Normal Colors Colors Colors Colors LOIOID IOD e I 111 1 Figure 3 22 Display Menu Restore Colors Zooming on Waveforms Using with Waveforms The TDS Oscilloscope can expand or compress zoom in or out on a waveform without ch
22. Label Rig Ta ates eo 1M 130 000 record length PRE et a i att TDS 7X4A TDS 7X4A Description Extend TDS 7X4A record length from 50 000 standard to 500 000 samples on one channel 250 000 on two channels and 130 000 samples on three or four channels 1R Rackmount Oscilloscope comes configured for installation in a 19 inch wide instrument rack For later field conversions order kit 016 1136 00 23 Two active probes Add two 750 MHz P6205 active probes TDS 7X4A 24 Four passive probes 26 Four active probes 2P Color printer Add four 500 MHz P6139A passive probes Add four 1 GHz P6245 active probes Tektronix Phaser 200e 300 dpi thermal transfer color printer Ithandles letter or A4 size Tektronix thermal paper and transparencies It can handle laser copy plain paper with the ColorCoat Transfer roll TDS 684A TDS 744A amp TDS 784A User Manual Appendix A Options and Accessories Table A 1 Options Cont Option Label Description 95 Calibration Data Report 96 ee calib atio Certificate Standard Accessories Calibration Certificate Certificate of Calibration which states this instrument meets or exceeds all warranted specifications and has been calibrated using standards and instruments whose accuracies are traceable to the National Institute of Standards and Technolog
23. MCross2 Timing measurement Time taken for the leading edge of a pulse to rise from a LowRef value default 10 to a HighRef value default 90 Figure B 3 shows a rising edge with the two crossings necessary to calculate a Rise Time measurement 1 Searching from Start to End find the first sample in the measurement zone less than LowRef TDS 684A TDS 744A amp TDS 784A User Manual Appendix B Algorithms RMS 2 From this sample continue the search to find the first positive crossing of LowkRef The time of this crossing is the low rise time or TLR Use linear interpolation if necessary 3 From TLR continue the search looking for a crossing of HighRef Update TLR if subsequent LowRef crossings are found If a HighRef crossing is found it becomes the high rise time or THR Use linear interpolation if necessary 4 RiseTime THR TLR Rise Time TLR THR High HighR ef LowR ef Low Figure B 3 Rise Time Amplitude voltage measurement The true Root Mean Square voltage If Start End then RMS the interpolated value at Waveform Start Otherwise End Waveform t dt RM S Start End Start x SampleInterval For details of the integration algorithm see below TDS 684A TDS 744A amp TDS 784A User Manual B 11 Appendix B Algorithms Integration Algorithm The integration algorithm used by the oscilloscope is as follows 2 is approxima
24. None Factors OIOI ai om a sons Chit 248m 21 pec 1993 10 28 23 I 10010 1 1 Figure 3 23 Zoom Mode with Horizontal Lock Set to None 6 TDS 684A only Press Horizontal Lock side to choose which waveforms to zoom horizontally Repeatedly press Horizontal Lock side to cycle through the three choices TDS 700A models only Press ZOOM gt Lock main gt All Live or None side TDS 684A TDS 744A amp TDS 784A User Manual 3 39 Acquiring and Displaying Waveforms Set Interpolation Reset Zoom Using Dual Window Mode TDS 700A Models Only 3 40 NOTE Although Zoom must be turned on to control which waveforms Zoom affects the setting for Horizontal Lock affects which waveforms the horizontal control positions whether Zoom is on or off The rules for the three settings are listed in step 5 on page 3 39 To change the interpolation method used press DISPLAY gt Settings main gt Display pop up gt Filter main gt Sin x x Interpolation or Linear Interpolation side To reset all zoom factors to their defaults do the following step TDS 684A only Press ZOOM gt Reset Zoom Factors side Press ZOOM gt Off side to return to normal oscilloscope not zoom operation TDS 700A models only Press ZOOM gt Reset main gt Reset Live Factors or Reset All Factors side Reset Live Factors resets only for live
25. m P6703A Opto Electronic Converter 1100 to 1700 nm DC to 1 GHz 1 V mW m P6711 Opto Electronic Converter 500 to 950 nm DC to 250 MHz 5 V mW m P6713 Opto Electronic Converter 1100 to 1700 nm DC to 300 MHz 5 V mW Accessory Software The optional accessories listed in Table A 4 are Tektronix software products recommended for use with your oscilloscope Table A 4 Accessory Software Software Part Number Wavewriter AWG and waveform creation S3FT400 LabWindows S3FG910 Warranty Information Check for the full warranty statements for this product and the products listed above on the first page after the title page of each product manual Service Assurance Tektronix offers the following services that you can purchase any time during the warranty period of this product m REPXXXX provides one year of post warranty repair support It is available in One year increments up to three years TDS 684A TDS 744A amp TDS 784A User Manual A 5 Appendix A Options and Accessories m CALXXXX provides one year of calibration support It is available in one year increments up to five years A 6 TDS 684A TDS 744A amp TDS 784A User Manual E Appendix B Algorithms The TDS Oscilloscope can take 25 automatic measurements By knowing how it makes these calculations you may better understand how to use your oscillo scope and how to interpret your results Measurement Variables The oscilloscope
26. 2 3 Save Recall SETUP 2 10 3 7 3 111 3 117 Save Recall WAVEFORM 3 114 3 117 SELECT 3 100 Glossary 9 SET LEVEL TO 50 3 54 SINGLE TRIG 3 26 3 55 STATUS 3 133 TRIGGER MENU 3 57 3 58 3 64 3 67 3 68 3 72 3 74 3 77 UTILITY 3 103 3 122 3 131 VERTICAL MENU 2 17 WAVEFORM OFF 2 18 3 8 3 32 ZOOM 3 37 3 38 Buttons CH1 CH2 3 8 Index 2 Channel selection 2 16 3 8 Main menu 2 3 Side menu 2 3 C Cables 3 130 Cal Probe Vertical menu 3 104 Calibration Certificate Option 9C A 3 Cart Oscilloscope A 1 Centronics 2 5 Port 3 123 3 128 CH1 CH2 buttons 3 8 Ch1 Ch2 Delayed Trigger menu 3 85 Chl Ch2 Main Trigger menu 3 58 3 65 3 68 3 69 3 73 3 74 3 76 3 77 Change Colors Color menu 3 34 Channel Glossary 2 Readout 2 6 3 8 3 38 Reference Indicator 2 6 3 8 Selection buttons 2 16 3 8 Trigger input 3 50 3 86 Channel readout 2 6 Channel reference indicator Glossary 2 Channels Selecting 3 7 3 48 Circuit loading Glossary 2 Class Glitch Main Trigger menu 3 72 Class Main Trigger menu 3 76 Pattern 3 64 Runt 3 74 Setup Hold 3 68 Slew Rate 3 77 State 3 67 Classes Pulse triggers 3 71 CLEAR MENU button 2 3 2 8 2 12 2 20 2 21 3 95 Clear Spool Hardcopy menu 3 126 Clipping derivative math waveforms 3 164 FFT math waveforms 3 153 how to avoid 3 153 3 164 3 169 integral math waveforms 3 169
27. Figure 3 33 TRIGGER Controls and Status Lights To manually change the trigger level when edge triggering or certain threshold levels when logic or pulse triggering turn the MAIN LEVEL knob It adjusts the trigger level or threshold level instantaneously no matter what menu if any is displayed To quickly obtain an edge trigger or a glitch or width pulse trigger press SET LEVEL TO 50 The oscilloscope sets the trigger level to the halfway point between the peaks of the trigger signal Set Level to 50 has no effect when trigger type is logic or video You can also set the level to 50 in the Trigger menu under the main menu item Level if edge trigger or glitch or width pulse trigger is selected Note that the MAIN LEVEL knob and menu items apply only to the main trigger level To modify the delayed trigger level use the Level item in the Delayed Trigger menu To force the oscilloscope to immediately start acquiring a waveform record even without a trigger event press the FORCE TRIG front panel button Forcing a trigger is useful when in normal trigger mode and the input signal is not supplying a valid trigger By pressing FORCE TRIG you can quickly confirm that there is a signal present for the oscilloscope to acquire Once that is established you can determine how to trigger on it press SET LEVEL TO 50 check trigger source setting and so on The oscilloscope recognizes and acts upon FORCE TRIG even when you press it bef
28. High High input resistance probes are considered typical oscilloscope probes The Input Resistance Probes high input resistance of passive probes typically 10 MQ provides negligible DC loading and makes them a good choice for accurate DC amplitude measure ments However their 8 pF to 12 pF over 60 pF for 1X capacitive loading can distort timing and phase measurements Use high input resistance passive probes for measurements involving m Device characterization above 15 V thermal drift applications TDS 684A TDS 744A amp TDS 784A User Manual E 1 Appendix E Probe Selection Low Impedance Zo Probes High Voltage Probes E 2 m Maximum amplitude sensitivity using 1X high impedance m Large voltage range between 15 and 500 V m Qualitative or go no go measurements Low impedance probes measure frequency more accurately than general purpose probes but they make less accurate amplitude measurements They offer a higher bandwidth to cost ratio These probes must be terminated in a 50 Q scope input Input capacitance is much lower than high Z passive probes typically 1 pF but input resistance is also lower 500 to 5000 Q typically Although that DC loading degrades amplitude accuracy the lower input capacitance reduces high frequency loading to the circuit under test That makes Zo probes ideal for timing and phase measurements when amplitude accuracy is not a major concern Zo probes are useful for measurem
29. Saving files to the floppy disk provides a convenient way to store hardcopies You can print hardcopies stored on disk at a site remote from where the hardcopies were captured using another TDS oscilloscope Or you might load TDS 684A TDS 744A amp TDS 784A User Manual Saving Waveforms and Setups To Print Using a Controller stored hardcopies from disk into your desktop publishing software that runs on a PC compatible computer To make your hardcopies use the procedures that follow Connect to a Hardcopy Device To connect a controller with two ports between the oscilloscope and the hardcopy device connect from the oscilloscope GPIB connector rear panel to the controller GPIB port and from the controller RS 232 or Centronics port to the hardcopy device See Figure 3 74 Use the GPIB port to remotely request and receive a hardcopy from the oscilloscope Use the RS 232 or the Centronics port on the controller to print output Digitizing Oscilloscope Hardcopy Device PC Compatible Centronics or GPIB Cable RS 232 Cable Figure 3 74 Connecting the Oscilloscope and Hardcopy Device Via a PC Print If your controller is PC compatible and it uses the Tektronix GURU or S3FG210 National Instruments GPIB PCII IIA GPIB package do the following steps to print a hardcopy 1 Use the MS DOS cd command to move to the directory that holds the software that came with
30. TDS 744A amp TDS 784A User Manual Appendix E Probe Selection Optical Probes Optical probes let you blend the functions of an optical power meter with the high speed analog waveform analysis capability of an oscilloscope You have the capability of acquiring displaying and analyzing optical and electrical signals simultaneously Applications include measuring the transient optical properties of lasers LEDs electro optic modulators and flashlamps You can also use these probes in the development manufacturing and maintenance of fiber optic control networks local area networks LANs fiber based systems based on the FDDI and SONET standard optical disk devices and high speed fiber optic communications systems NOTE When you connect any probe with a TEKPROBE level 2 interface to the oscilloscope the input impedance of the oscilloscope automatically becomes 50 Q If you then connect a high input impedance passive probe you need to set the input impedance back to 1 MQ The procedure To Change Vertical Parame ters on page 3 12 explains how to change the input impedance Time to Voltage Converter The instantaneous time interval to voltage converter TVC continuously converts consecutive timing measurements to a time interval versus time waveform Timing variations typically appear as left to right motion or jitter on an oscilloscope Time base or trigger holdoff adjustments may improve display stability but
31. The slew rate setting is not the slew rate of the pulse instead it is the slew rate against which the oscilloscope compares the slew rate of pulse see above You set the slew rate setting indirectly by setting the ratio of delta voltage to delta time as Upper Threshold Setting Lower Threshold Setting Sale Nae Delta Time Setting Substituting the threshold and delta time settings for the setup in Fig ure 3 46 Slew Rate Setting eet 16 0 mV ns The trigger bar indicators long horizontal bars point to the upper and lower thresholds The pair cursors which are aligned to threshold levels read out a delta voltage of approximately 4 V and a delta time of 200 ns between the threshold levels Therefore the slew rate of the pulse edge triggered on is Slew Rate Measured amp 4 Volts _ 99 mV ns dt 200 ns The Trigger When side menu indicates the oscilloscope will trigger on pulses with slew rates slower than the slew rate setting Since the pulse edge slews at 20 mV ns which is faster than the slew rate setting of 16 mV ns the oscilloscope triggers The trigger point indicator shows where the oscilloscope triggers For a slew rate triggered waveform the trigger point is always at the threshold crossed last the upper threshold for positive polarity settings the lower for negative settings Set the Mode and Holdoff Mode and holdoff can be set for all standard trigger types and classes To set mode and holdof
32. When you select the pulse class Runt the oscilloscope will trigger on a short pulse that crosses one threshold but fails to cross a second threshold before recrossing the first To set up for runt triggering do the following procedures Select Runt Triggering Press TRIGGER MENU gt Type main gt Pulse pop up gt Class main gt Runt pop up See Figure 3 45 Select the Source To specify which channel becomes the pulse trigger source Press TRIGGER MENU gt Type main gt Pulse pop up gt Source main gt Ch1 Ch2 Ch3 or Ch4 side The source selected becomes the trigger source for all four trigger classes Select the Polarity To specify the direction of the runt pulse Press TRIGGER MENU gt Type main gt Pulse pop up gt Class main gt Runt pop up gt Polarity main gt Positive Negative or Either side Positive looks for positive going runt pulses TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms Negative looks for negative going runt pulses Either looks for both positive and negative runt pulses Set to Trig When To determine how wide a runt pulse the oscilloscope will trigger on 1 Press TRIGGER MENU gt Type main gt Pulse pop up gt Class main gt Runt pop up gt Trig When main 2 Press Occurs to trigger on all runt pulses regardless of width 3 Press Runt is Wider Than side to trigger only on runt pulses that exceed the w
33. _ a Appendix C Packaging for Shipment If you ship the TDS Oscilloscope pack it in the original shipping carton and packing material If the original packing material is not available package the instrument as follows 1 Obtain a corrugated cardboard shipping carton with inside dimensions at least 15 cm 6 in taller wider and deeper than the oscilloscope The shipping carton must be constructed of cardboard with 170 kg 375 pound test strength If you are shipping the oscilloscope to a Tektronix field office for repair attach a tag to the oscilloscope showing the instrument owner and address the name of the person to contact about the instrument the instrument type and the serial number Wrap the oscilloscope with polyethylene sheeting or equivalent material to protect the finish Cushion the oscilloscope in the shipping carton by tightly packing dunnage or urethane foam on all sides between the carton and the oscilloscope Allow 7 5 cm 3 in on all sides top and bottom Seal the shipping carton with shipping tape or an industrial stapler NOTE Do not ship the oscilloscope with a disk inside the disk drive When the disk is inside the drive the disk release button sticks out This makes the button more prone to damage than otherwise TDS 684A TDS 744A amp TDS 784A User Manual C 1 Appendix C Packaging for Shipment C 2 TDS 684A TDS 744A amp TDS 784A User Manual a Se a ee ee Ap
34. e eee eect eee eee 3 97 Taking Graticule Measurements 0 cece eee eee eee tenes 3 101 Optimizing Measurement Accuracy SPC and Probe Cal 3 102 Saving Waveforms and Setups cece cccce cece ccscees 3 111 Saving and Recalling Setups 0 0 00 cee cece eee eee eee 3 111 Saving and Recalling Waveforms 00 0 0 cece eee eee eee 3 114 Managing the File System 00 02 eee eee 3 117 Printing a Hardcopy eese esner a eee eect eens 3 120 Communicating with Remote Instruments 02 00 00005 3 128 Determining Status and Accessing Help eeeeeee 3 133 Displaying Status oip ainin e a ccc cee eee een ene a 3 133 Displaying Help amp ox de ses ne eek netic eae a a oe a eS 3 135 Using Features for Advanced Applications 0 ee008 3 137 Lint VeSun E ovate ieee oe ee SSR ee ere has Shae Bees 3 137 Wavetorm Math cn 3 3 4 2 eters hae T bb we eee BA Bae Re Ss 3 142 Fast Fourier Transforms 0 AE ee eee nent n eens 3 144 Waveform Differentiation 2 0 0c cece tenes 3 161 Wavetorm Integration isc sone Sees ee nes Ee ee es Be ae ees E 3 165 Appendix A Options and Accessories 0 0c cece ese ce cece A 1 Appendix B Algorithms sssssssesesssesesseceseseseoe B 1 Appendix C Packaging for Shipment essssssseseseseses C 1 Appendix D Factory Initialization Settings 000 D 1 Appendix E Probe S
35. frequency between the long horizontal bars of both paired cursors from the bottom A readout You can use automated measurements to measure FFT math waveforms Use the procedure To Take Automated Measurements found in Waveform Differentiation on page 3 163 There are several characteristics of FFTs that affect how they are displayed and should be interpreted Read this topic to learn about the FFT frequency domain record how the source waveform relates to the record length frequency resolution and frequency range of that record The FFT frequency domain waveform is the FFT math waveform that you display Continue reading the topics that follow to learn how to optimize the oscilloscope setup for good display of your FFT waveforms TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications FFTs May Not Use All of the Waveform Record The FFT math waveform is a display of the magnitude or phase data from the FFT frequency domain record This frequency domain record is derived from the FFT time domain record which is derived from the waveform record All three records are described below Waveform Record the complete waveform record acquired from an input channel and displayed from the same channel or a reference memory The length of this time domain record is user specified from the Horizontal menu The waveform record is not a DSP Math waveform FFT Time Domain Record that part of the wavefo
36. or Peak Detect TDS 700A models only Envelope searches for samples with the highest and lowest values over multiple acquisitions Peak Detect mode does the same but in a single acquisition Either can detect faster signal components over time m Try pressing the InstaVu acquisition button TDS 700A models only InstaVu mode results in waveform displays similar to those obtained using analog oscilloscope due to its fast waveform capture rate Customizing the Display The TDS Oscilloscope can display waveform records and other display elements in different ways This subsection describes how to adjust the oscilloscope display style intensity level graticule and format TDS 684A TDS 744A amp TDS 784A User Manual 3 27 Acquiring and Displaying Waveforms Change Display Settings Select the Display Style 3 28 NOTE TDS 700A models only This subsection assumes you are using Normal acquisitions mode and gives display settings for this mode If you select InstaVu acquisitions procedures for making Style Format and Readout display settings differ and some selections are not permitted See Using InstaVu Acquisition Mode on page 3 43 for setup differences and Incompatible Modes on page 3 45 To bring up the Display menu Press DISPLAY gt Settings main gt Display pop up The Display menu allows you to adjust the style intensity level graticule and format features described below The Color menu allows
37. page 3 142 MENU HARDCOPY RUN STOP UTILITY SHIFT DISPLAY ACQUIRE MENU DELAYED TRIG TRIGGER ARM MENU SINGLE TRIG FORCE TRIG a o o O EN SELECT _ L InstaVu C lt Se lt PROBE COMPENSATION XQ SIGNAL GND PROBE AT iy 12 10pF JX 50 2 400V pk lt 5V RMS CH 3 Vertical Controls page 3 10 Zoom page 3 37 Ground Horizontal Controls 2 4 page 3 13 Triggering page 3 49 Delay Triggering page 3 80 Edge Triggering page 3 57 Logic Triggering page 3 60 Pulse Triggering page 3 70 Cursor Measurements page 3 97 InstaVu page 3 43 TDS 700A models only Color page 3 33 Display Settings page 3 27 Remote Communication page 3 128 Probe Calibration page 3 104 TDS 684A TDS 744A amp TDS 784A User Manual Operating Interface Maps Rear Panel Map Principal Power Switch GPIB Connector page 1 5 Centronics Connector RS 232 Connector page 3 128 VGA Output Fuse Serial Number Power Connector Rear Panel Connectors Security Bracket Paget pageza SIGNAL OUTPUT Provides Analog Signal Output AUX TRIGGER INPUT Provides Auxiliary Trigger Signal Input MAIN TRIGGER OUTP
38. the input impedance of the oscilloscope automatically becomes 50 Q If you then connect a passive probe you need to set the input impedance back to I MQ The procedure To Change Vertical Scale and Position on page 3 10 explains how to change the input impedance Also please read Input Impedance Considerations on page 3 5 for more information High Speed Active Probes Active probes offer low input capacitance 1 to 2 pF typical while maintaining the higher input resistance of passive probes 10 KQ to 10 MQ Like Zo probes active probes are useful for making accurate timing and phase measurements However they do not degrade the amplitude accuracy Active probes typically have a dynamic range of 8 to 15 V Differential Probes Differential probes determine the voltage drop between two points in a circuit under test Differential probes let you simultaneously measure two points and to display the difference between the two voltages Active differential probes are stand alone products designed to be used with 50 Q inputs The same characteristics that apply to active probes apply to active differential probes Fixtured Active Probes In some small geometry or dense circuitry applications such as surface mounted devices SMD a hand held probe is too big to be practical You can instead use fixtured or probe card mounted active probes or buffered amplifiers to TDS 684A TDS 744A amp TDS 784A User Manual E 3 Appendix E Probe S
39. 1 Gs second 2 Gs second Three or Four One 500 Ms second 1 Gs second 1 When real time sampling Gs Gigasamples Ms Megasamples No of Channels Turned On Digitizers Used Per Channel TDS 684A TDS 744A amp TDS 784A User Manual 3 19 Acquiring and Displaying Waveforms The Acquisition Modes 3 20 Once you set horizontal scale to exceed the maximum digitizing rate for the number of channels in use see Table 3 2 the oscilloscope will not be able to get enough samples to create a waveform record At that point the oscilloscope will either interpolate to calculate additional samples or it will switch from real to equivalent time sampling to obtain additional samples See Interpolation on page 3 18 and Equivalent Time Sampling on page 3 18 All three TDS Oscilloscopes support the following three acquisition modes Sample Envelope and Average TDS 700A Oscilloscopes support two additional acquisition modes Peak Detect and Hi Res Keep in mind which modes apply to your model oscilloscope as you read the following descriptions Sample the mode most commonly used Peak Detect and Hi Res modes operate in real time on a single trigger event provided that the oscilloscope can acquire enough samples for each trigger event Envelope and Average modes operate on multiple acquisitions the oscilloscope averages or envelopes several waveforms on a point by point basis For TDS 700A models only Hi
40. 1 cycle per second If Period 0 or is otherwise bad return an error Frequency 1 Period High 100 highest voltage reference value See High Low on page B 1 Tf Using the min max measurement technique High Max TDS 684A TDS 744A amp TDS 784A User Manual B 7 Appendix B Algorithms Low Maximum Mean Minimum Negative Duty Cycle Negative Overshoot 0 lowest voltage reference value calculated See High Low on page B 1 Using the min max measurement technique Low Min Amplitude voltage measurement The maximum voltage Typically the most positive peak voltage Examine all Waveform samples from Start to End inclusive and set Max equal to the greatest magnitude Waveform value found The arithmetic mean for one waveform Remember that one waveform is not necessarily equal to one cycle For cyclical data you may prefer to use the cycle mean rather than the arithmetic mean If Start End then return the interpolated value at Start Otherwise End Waveform t dt Mean Start End Start x SampleInterval For details of the integration algorithm see page B 12 Amplitude voltage measurement The minimum amplitude Typically the most negative peak voltage Examine all Waveform samples from Start to End inclusive and set Min equal to the smallest magnitude Waveform value found Timing measurement The ratio of the negative pulse width to the sig
41. 138 TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications Tek Run 100kKS 5 Sample Limit Test Template Template Source chi Template Destination Refi V Limit 4omaiv H Limit 4omdiv 200mv M 500s Chis 252mv ye i i ore Oooo o Template Mode Stop After E Limit Test RRR Sample R S button Setup Sources Limi Test DIP CIO O O CO Figure 3 83 Acquire Menu Create Limit Test Template 4 Press V Limit side Enter the vertical voltage tolerance value using the general purpose knob or keypad 5 Press H Limit side Enter the horizontal time tolerance value using the general purpose knob or keypad Tolerance values are expressed in fractions of a major division They represent the amount by which incoming waveform data can deviate without having exceeded the limits set in the limit test The range is from O the incoming waveform must be exactly like the template source to 5 major divisions of tolerance 6 When you have finished specifying the limit test template press OK Store Template side This action stores the specified waveform in the specified destination using the specified tolerances Until you have done so the template waveform has been defined but not created To avoid overwriting the template you have just created store any new
42. ENA En nT SEET verify or change the waveform to which Delay will be measured the Search Direction and the Edges at which to measure when you are satisfied with the selections press Create Measurement E Press CLEAR MENU to return to the Measure menu without creating the Delay measurement agmv OK f Create Measurement Delay To Edges chi gt F gt F a a a OIIO Figure 3 56 Measure Delay Menu Delay To 3 94 TDS 684A TDS 744A amp TDS 784A User Manual Measuring Waveforms 3 Press MEASURE gt Select Measrmnt main gt Delay side gt Edges main A side menu of delay edges and directions will appear Choose from one of the combinations displayed on the side menu using the following information m The selection you choose defines which edges you want the delayed measurement to be made between m The upper waveform on each icon represents the from waveform and the lower one represents the fo waveform m The direction arrows on the choices let you specify a forward search on both waveforms or a forward search on the from waveform and a backwards search on the to waveform The latter choice is useful for isolating a specific pair of edges out of a stream 4 To take the measurement you just specified press Delay To main gt OK Create Measurement side To exit the Measure Delay menu rather than creating a delay meas
43. Horiz Scale main gt Main Scale or Delayed Scale side and use the keypad or the general purpose knob to change the scale values TDS 684A TDS 744A amp TDS 784A User Manual 3 15 Acquiring and Displaying Waveforms To Select the Delayed Time Base To Find More Information Horizontal Position To set the horizontal position to specific values in the menu instead of using the Horizontal POSITION knob Press HORIZONTAL MENU gt Horiz Pos main gt Set to 10 Set to 50 or Set to 90 side to choose how much of the waveform will be displayed to the left of the display center You can also control whether changing the horizontal position setting affects all displayed waveforms just the live waveforms or only the selected waveform See Zoom a Waveform on page 3 38 for the steps to set the horizontal lock feature You also can select Delayed Runs After Main or Delayed Triggerable Use the main time base for most applications Use the delayed time base when you want to delay an acquisition so it captures and displays events that follow other events See Jo Find More Information below To perform tutorials that teach selecting scaling and positioning of waveforms see Example 1 Displaying a Waveform on page 2 13 and Example 2 Displaying Multiple Waveforms on page 2 15 To learn how to use delay with waveforms see Delayed Triggering on page 3 80 To learn how to magnify waveforms see Zooming on Waveforms on page 3 3
44. Limit Test side once to toggle it to ON When you set Limit Test to ON the oscilloscope compares incoming waveforms against the waveform template stored in reference memory according to the settings in the Limit Test Sources side menu Single Waveform You can compare a single waveform against a single template When making a Comparisons single waveform versus a single template comparison consider the following operating characteristics m The waveform will be repositioned horizontally to move the first sample in the waveform record that is outside of template limits to center screen m The position of the waveform template will track that of the waveform Multiple Waveform You can also compare more than one waveform against a single template or Comparisons more than one waveform with each one compared against its own template or a common template When setting up for such comparisons consider the following operating characteristics m You should set Horizontal Lock to None in the Zoom side menu push ZOOM and press repeatedly Horizontal Lock to None See Zoom a Waveform on page 3 38 for more information on horizontal lock m With horizontal lock set as just described the oscilloscope will reposition each waveform horizontally to move the first sample in the waveform record that is outside of template limits to center screen m If you are comparing each waveform to its own template the position of each waveform template will t
45. Manual Acquiring and Displaying Waveforms Input Impedance To ensure proper coupling of your input signals to the oscilloscope consider the Considerations following points when you use 50 Q coupling with any channel m The oscilloscope does not accurately display frequencies under 200 kHz if AC coupling is selected m The oscilloscope reduces the maximum volts division setting for the channel to 1 V from 10 V to 10 V from 100 V with a X10 probe attached since input amplitudes appropriate for the higher settings would overload the 50 Q input m The oscilloscope switches to 50 Q and disables AC coupling and switches coupling to DC if AC is selected if you connect an active probe such as the P6245 probe Such probes also reduce the maximum volts div to 10 V as just described This behavior results in 50 Q nonAC coupling which is appropriate for such probes NOTE If you remove an active probe the oscilloscope does not switch coupling back to 1 MQ nor AC if it was previously selected Nor does it restore a volts division setting limited due to 50 Q selection when you restore 1 MQ coupling In general you must set channel scale input coupling and impedance appropriate for your input coupling scheme Be sure to switch to 1 MQ for any input signal not from a 50 Q system To Find More Information To find a procedure for changing the coupling and input impedance settings see To Change Vertical Parameters on page 3 12 To
46. Math 3 143 FFT 3 146 Hamming 3 148 Hanning 3 148 intg 3 166 Linear RMS 3 147 Math1 Math2 Math3 3 146 3 162 3 166 Math1 2 3 3 144 No Process 3 144 OK Create Math Waveform 3 143 3 166 Phase deg 3 147 Phase rad 3 147 Rectangular 3 147 Reference waveform status 3 116 Set 1st Source to 3 143 Set 2nd Source to 3 143 Set FFT Source to 3 146 Set FFT Vert Scale to 3 147 Set FFT Window to 3 147 Set Function to 3 143 Set Function to 3 162 3 166 Set operator to 3 143 Set Single Source to 3 142 3 143 Set Single Source to 3 162 3 166 Single Wfm Math 3 142 3 162 3 166 N NAND Glossary 6 NAND Main Trigger menu 3 66 3 68 Negative duty cycle 3 89 Index 9 Index Negative overshoot 3 89 Negative width 3 89 Negative Main Trigger menu 3 73 3 74 3 77 No Process More menu 3 144 Noise reducing in FFTs 3 154 reducing in phase FFTs 3 148 3 157 Noise Rej Main Trigger menu 3 58 NOR Glossary 7 NOR Main Trigger menu 3 66 3 68 Normal trigger mode 3 51 Glossary 7 Normal Color menu 3 34 Normal Main Trigger menu 3 59 NTSC Display menu 3 31 Nyquist frequency 3 155 O OFF Real Time Only Acquire menu 3 24 Off Bus Utility menu 3 131 Offset DC See DC Offset Vertical 3 13 vertical 3 153 3 164 3 169 Offset Vertical menu 3 13 OK Confirm Clear Spool Hardcopy menu 3 126 OK Create Math Wfm More menu 3 143 OK Cre
47. Mid2Ref crossings of two different traces or two different places on the same trace Delay measurements are actually a group of measurements To get a specific delay measurement you must specify the target and reference crossing polarities and the reference search direction Delay the time from one MidRef crossing on the source waveform to the Mid2Ref crossing on the second waveform Delay is not available in the Snapshot display Timing measurement The time taken for the falling edge of a pulse to drop from a HighRef value default 90 to a LowRef value default 10 Figure B 2 shows a falling edge with the two crossings necessary to calculate a Fall measurement 1 Searching from Start to End find the first sample in the measurement zone greater than HighRef TDS 684A TDS 744A amp TDS 784A User Manual Appendix B Algorithms 2 From this sample continue the search to find the first negative crossing of HighRef The time of this crossing is THF Use linear interpolation if necessary 3 From THF continue the search looking for a crossing of LowRef Update THF if subsequent HighRef crossings are found When a LowRef crossing is found it becomes TLF Use linear interpolation if necessary 4 FallTime TLF THF Fall Time as THF TLF High HighR ef LowRef Low Figure B 2 Fall Time Frequency Timing measurement The reciprocal of the period Measured in Hertz Hz where 1 Hz
48. Point 3 29 Readout Cursor Paired 3 163 Readout cursor H Bars 3 149 3 163 3 167 Paired cursors 3 150 3 168 V Bars 3 149 3 163 3 168 Readout Display menu 3 29 3 31 Real time sampling 3 17 Real time sampling Glossary 8 Rear panel 2 5 Recall Setups 3 111 3 132 Recall Factory Setup Save Recall Setup menu 3 113 TDS 684A TDS 744A amp TDS 784A User Manual Recall Saved Setup Save Recall Setup menu 3 112 Recalling Waveforms 3 114 Record Length Limit in Hi Res mode 3 15 Record length 3 15 Glossary 9 derivative math waveforms 3 162 integral math waveforms 3 166 Option 1M A 2 Record Length Horizontal menu 3 15 Record lengths Incompatible with InstaVu 3 46 Record View 2 6 3 9 3 13 3 56 Rectangular window 3 147 Ref Color menu 3 36 Ref1 Ref2 Ref3 Ref4 File Save Recall Waveform menu 3 115 Ref1 Ref2 Ref3 Ref4 Reference waveform status 3 116 Reference Indicator Channel 3 8 Reference levels 2 21 Defining for Measure 3 93 Reference Levels Measure menu 3 93 Reference memory Glossary 9 Reject Glitch Main Trigger menu 3 73 Remote communication 3 128 3 132 Remote operation Communicating with Remote Instruments 3 128 Connecting to the GPIB 3 130 GPIB interface requirements 3 129 GPIB Protocols 3 129 Interconnect cabling 3 130 Preparation for 3 129 Procedures for 3 130 Selecting and configuring the port 3 131 Remove Measrmnt Measure men
49. Press Set to 0 divs side if you want to reset the reference point of the selected waveform to the center of the display TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms To Check the Horizontal Status Offset Use offset to subtract DC bias before examining a waveform For example you might want to display a small ripple for example 100 mV of ripple on a power supply output for example a 15 V output Adjust offset to keep the ripple on screen while setting the vertical scale sensitive enough to best display the ripple To adjust offset press VERTICAL MENU gt Offset main Then use the general purpose knob or keypad to set the vertical offset Press Set to 0 V side if you want to reset the offset to zero Check the Record View to determine the size and location of the waveform record and the location of the trigger relative to the display See Figure 3 7 Check the Time Base readout at the lower right of the display to see the time division settings and the time base main or delayed being referred to See Figure 3 7 Also see Figure 3 5 on page 3 10 Since all live waveforms use the same time base the oscilloscope only displays one time base and time division setting for all the active channels Tek Stopped Record View Readout 2659 Acquisitions Delay Tims16 50ns Time Base Main Only Intensified age Delayed Only
50. Res Envelope and Average modes are not available when in InstaVu mode see Incompatible Modes on page 3 45 Figure 3 13 illustrates the different modes and lists the benefits of each It will help you select the appropriate mode for your application Refer to it as your read the following descriptions of each mode Sample Mode In Sample mode the oscilloscope creates a record point by saving the first sample of perhaps many during each acquisition interval An acquisition interval is the time covered by the waveform record divided by the record length Sample mode is the default mode Envelope Mode Envelope mode lets you acquire and display a waveform record that shows the extremes in variation over several acquisitions You specify the number of acquisitions over which to accumulate the data The oscilloscope saves the highest and lowest values in two adjacent intervals similar to the Peak Detect mode But Envelope mode unlike Peak Detect gathers peaks over many trigger events After each trigger event the oscilloscope acquires data and then compares the min max values from the current acquisition with those stored from previous acquisitions The final display shows the most extreme values for all the acquisitions for each point in the waveform record Average Mode Average mode lets you acquire and display a waveform record that is the averaged result of several acquisitions This mode reduces random noise The oscilloscope acq
51. Setting Up for the Examples 2 9 Settings Display menu 3 28 3 33 Setup menu 2 10 3 7 Setup Hold trigger Maximum hold time NOTE 3 64 Negative setup or hold times 3 63 Positive setup or hold times 3 62 Trigger point location 3 62 Setup Hold trigger 3 61 How to setup 3 68 3 86 Setups Save and recall 3 111 3 132 Shipping C 1 Side menu Glossary 10 Side menu buttons 2 3 Glossary 10 SIGNAL OUTPUT BNC 2 5 Signal Path Compensation 1 3 3 102 Sin x x interpolation 3 19 3 31 Glossary 5 Sin x x interpolation Display menu 3 31 Single Acquisition Sequence Acquire menu 3 26 SINGLE TRIG button 3 26 3 55 Single Wfm Math More menu 3 142 Single Shot sampling 3 17 Slew rate setting How derived 3 80 Slew Rate Trigger 3 72 Slew rate trigger 3 71 Glossary 9 Glossary 10 600 ps limitation 3 79 3 86 7 5 ns limitation 3 79 3 86 How to set up 3 77 3 86 Slope Glossary 10 Slope Delayed Trigger menu 3 85 Slope Main Trigger menu 3 60 Slope Trigger 3 53 Snapshot Readout 3 95 Snapshot of Measurements 2 23 3 95 Snapshot Measure menu 3 95 Software version 3 133 TDS 684A TDS 744A amp TDS 784A User Manual Index Source Delayed Trigger menu 3 85 Source Main Trigger menu 3 58 3 73 3 74 3 76 3 77 Spectral Color menu 3 34 Spooler Hardcopy 3 126 Start up 1 3 State trigger 3 61 3 67 3 86 How to set up 3 67 3 86 State Main Tri
52. TDS 784A User Manual Index Intensified 3 83 3 84 Main Scale 3 15 Record Length 3 15 Set to 10 3 16 Set to 50 3 16 Set to 90 3 16 Time Base 3 83 Trigger Position 3 15 HORIZONTAL MENU button 3 53 3 83 Horizontal POSITION knob 3 14 3 39 Horizontal Readouts 3 13 Horizontal SCALE knob 3 14 3 39 HPGL 3 121 HPGL Hardcopy menu 3 122 Hue Color menu 3 34 I O Status menu 3 133 TO Utility menu 3 122 Independent Cursor menu 3 100 Infinite Persistence Display menu 3 28 Installation 1 4 InstaVu 3 43 3 48 Glossary 5 Glossary 12 InstaVu mode How to use 3 43 Modes incompatible with 3 45 Versus Normal DSO mode illustrated 3 44 Waveform capture rate 3 43 Integral math waveform 3 166 applications 3 165 automated measurements of 3 169 derivation of 3 166 magnifying 3 165 3 169 procedure for displaying 3 166 procedure for measuring 3 167 record length of 3 166 Integration Waveform 3 165 Intensified Samples Display menu 3 28 Intensified Horizontal menu 3 83 3 84 Intensity Glossary 5 Intensity Display menu 3 29 3 48 Interleaf 3 121 Interleaf Hardcopy menu 3 122 Interleaving 3 19 Glossary 5 Interpolation 3 18 3 20 3 31 Glossary 5 And zoom 3 38 FFT distortion 3 155 Incompatible with InstaVu 3 46 linear versus sin x x 3 155 IRE NTSC Cursor menu 3 101 TDS 684A TDS 744A amp TDS 784A User Manual K Ke
53. Upper eam am ee us eu GOGO Figure 3 25 Dual Zoom Shown Dual Window Preview Mode NOTE To make setting up Dual Zoom easier turn on Preview in the side menu In this dual window mode the zoomed display appears in the top graticule while the lower graticule shows the two zoomed portions enclosed in two boxes on the unzoomed waveform Adjusting offset moves the right box relative to the left box which remains stationary The associated zoomed waveform in the upper graticule moves to track the offset changes You can also adjust the waveform relative to the zoom boxes by selecting the lower graticule and adjusting the vertical and horizontal control knobs See Using Dual Window Mode on page 3 40 3 42 TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms Using InstaVu Acquisition Mode TDS 700A Models Only The TDS 744A and TDS 784A Oscilloscopes can use InstaVu acquisition mode to reduce the dead time between waveform updates that normally occur when digitizing storage oscilloscopes DSOs acquire waveforms InstaVu mode can capture and display transient deviations such as glitches or runt pulses often missed during longer dead times that accompany normal DSO display This subsection describes how to use InstaVu mode and how it differs from normal acquisition mode Waveform Capture Rate Figure 3 26 illustrates how InstaV
54. VGA 2 5 Contrast Display menu 3 29 Conventions xiv Copy File Utilities menu 3 119 Coupling 2 17 Ground Glossary 4 Selecting 3 12 3 48 Trigger 3 52 3 86 Coupling Waveforms 3 3 Coupling Delayed Trigger menu 3 85 TDS 684A TDS 744A amp TDS 784A User Manual Coupling Main Trigger menu 3 58 Coupling Vertical menu 3 12 Create Directory File Utilities menu 3 119 Create Limit Test Template Acquire menu 3 138 Create Measrmnt Measure Delay menu 3 95 Cross Hair Display menu 3 31 Current probes E 4 Cursor Horizontal bar 3 97 Measurements 3 97 modes 3 98 Paired 3 97 readout 3 98 Setting adjustment response speed 3 101 Vertical bar 3 97 CURSOR button 3 99 Cursor measurements 3 87 Cursor menu 3 99 3 149 3 167 1 seconds Hz 3 101 Amplitude Units 3 101 Base 3 101 Function 3 99 3 100 H Bars 3 99 3 100 Independent 3 100 IRE NTSC 3 101 seconds 3 101 Time Units 3 101 Tracking 3 100 Video Line Number 3 101 Cursor readout H Bars 3 149 3 163 3 167 Paired 3 163 Paired cursors 3 150 3 168 V Bars 3 149 3 163 3 168 Cursors 3 97 3 101 3 110 Glossary 2 How to use 3 99 with derivative waveforms 3 163 with FFT waveforms 3 149 with integral waveforms 3 167 Cycle area 3 88 Glossary 3 Cycle mean 3 88 Glossary 3 Cycle RMS 3 88 Glossary 3 D Data Source Main Trigger menu 3 68 Date Time On hardcopies 3 123 To s
55. When you choose the XY format any channel or reference displayed is assigned to the axis indicated in Table 3 6 and displayed as part of an XY pair If only one source in an XY pair is displayed the oscilloscope automatically turns on the other source to complete the XY pair when you select XY Moreover once XY is on selecting either source in a pair turns the pair on pressing WAVEFORM OFF for either source in the pair removes both sources from the display Table 3 6 XY Format Pairs XY Pair X Axis Source Y Axis Source ChlandCh2 Chl Ch2 Ch3andCh4 Ch3 Ch4 Ref 1 and Ref 2 Refl Ref 2 Ref 3 and Ref 4 Ref 3 Ref 4 Since selecting YT or XY affects only the display the horizontal and vertical scale and position knobs and menus control the same parameters regardless of the mode selected Specifically in XY mode the horizontal scale will continue to control the time base and the horizontal position will continue to control which portion of the waveforms are displayed XY format is a dot only display although it can have persistence The Vector style selection has no effect when you select XY format You cannot display Math waveforms in XY format They will disappear from the display when you select XY NOTE Use of XY at higher room temperatures or with higher intensity display formats such as the white fields in the Hardcopy palette can temporarily degrade display quality 3 32 TDS 684A TDS 744A amp TDS 784A Use
56. also can adjust the waveform position using the offset option in the Vertical menu discussed later in this section Tek Run 100kKS 5 Sample ch Coupling Impedance Vertical Readout m 20omv M 500s Chi 252mv i HA 50 Benne Bandwidth M2 Scale position offset Cal Probe Full iting a div ov Pass PIC C IO O O O Figure 3 6 Vertical Readouts and Channel Menu By changing the vertical scale you can focus on a particular portion of a waveform By adjusting the vertical position you can move the waveform up or down on the display Adjustment of vertical position is particularly useful when you are comparing two or more waveforms TDS 684A TDS 744A amp TDS 784A User Manual 3 11 Acquiring and Displaying Waveforms 3 12 To Change Vertical Parameters DC ACM GND To select the coupling bandwidth and offset for the selected waveform use the Vertical menu Figure 3 6 This menu also lets you numerically change the position or scale instead of using the vertical knobs To make such changes do the following procedures Coupling To choose the type of coupling for attaching the input signal to the vertical attenuator for the selected channel and to set its input impedance Press VERTICAL MENU gt Coupling main gt DC AC GND or Q side m DC coupling shows both the AC and DC components of an in
57. an accidental instrument reset could destroy a setup that took a long time to create the oscilloscope asks you to verify the Recall Factory Setup selection See Figure 2 3 3 Press the button to the right of the OK Confirm Factory Init side menu item NOTE This manual uses the following notation to represent the sequence of selections you made in steps 1 2 and 3 Press save recall SETUP gt Recall Factory Setup main gt OK Confirm Factory Init side D Note that a clock icon appears on screen The oscilloscope displays this icon when performing operations that take longer than several seconds 4 Press SET LEVEL TO 50 see Figure 2 4 to be sure the oscilloscope triggers on the input signal A TRIGGER MAIN LEVEL TRIG D READY DELAYED TRIG arm TRIGGER MENU SET LEVEL TO 50 SET LEVEL TO 50 Button gt __ Figure 2 4 Trigger Controls Examine the Display Read the following information to become familiar with the oscilloscope display Elements before doing the examples Figure 2 5 shows the display that results from the oscilloscope reset There are several important points to observe m The trigger level bar shows that the waveform is triggered at a level near 50 of its amplitude from step 4 m The trigger position indicator shows that the trigger position of the waveform is located at the horizontal center of the graticule TDS 684A TDS 744A amp TDS 784A User Manual 2
58. calculates the histogram based High and Low values as follows 1 It makes a histogram of the record with one bin for each digitizing level 256 total 2 It splits the histogram into two sections at the halfway point between Min and Max also called Mid 3 The level with the most points in the upper histogram is the High value and the level with the most points in the lower histogram is the Low value Choose the levels where the histograms peak for High and Low If Mid gives the largest peak value within the upper or lower histogram then return the Mid value for both High and Low this is probably a very low amplitude waveform If more than one histogram level bin has the maximum value choose the bin farthest from Mid This algorithm does not work well for two level waveforms with greater than about 100 overshoot The user sets the various reference levels through the Reference Level selection of the Measure menu They include HighRef the waveform high reference level Used in fall time and rise time calculations Typically set to 90 You can set it from 0 to 100 or to a voltage level MidRef the waveform middle reference level Typically set to 50 You can set it from 0 to 100 or to a voltage level LowRef the waveform low reference level Used in fall and rise time calculations Typically set to 10 You can set it from 0 to 100 or to a voltage level Mid2Ref the middle reference level f
59. eee nee 3 165 TDS 684A TDS 744A amp TDS 784A User Manual SSS Acquiring and Displaying Waveforms To use the TDS Oscilloscope to measure or monitor waveforms you need to know how to acquire select and display those waveforms properly To help you do so this section describes how to do the following tasks m How to couple waveforms to the oscilloscope channels m How to select channels to turn on and off their display m How to size and position the selected channel on screen m How to use the menus to set vertical coupling offset and bandwidth and horizontal time base record length and so on parameters This section also describes how to choose the appropriate acquisition mode for acquiring your waveform how to customize the display including selecting the color of the display elements and how to use the Zoom FastFrame and InstaVu features Coupling Waveforms to the Oscilloscope Tektronix produces a variety of probes and cables suitable for connecting various types of signals to the input channels of this product This subsection covers two topics important to coupling Probe Compensation and Input Impedance Considerations Tektronix ships the P6139A passive probe with the TDS 744A Oscilloscope as a standard accessory The TDS 684A and TDS 784A Oscilloscopes ship without standard probes but Tektronix recommends you order the P6245 active probe to take advantage of the 1 GHz bandwidth of these two osci
60. electrical shock be sure that the power cord is disconnected before checking the fuse 3 Check the fuse to be sure it is the proper type and rating see Figure 1 1 You can use either of two fuses Each fuse requires its own cap see Table 1 2 The oscilloscope is shipped with the UL approved fuse installed 4 Check that you have the proper electrical connections The oscilloscope requires 90 to 250 VACprms continuous range 45 Hz to 440 Hz and may require up to 300 W 5 Connect the proper power cord from the rear panel power connector see Figure 1 1 to the power system Power Connector ofzo Principal Power Switch Fuse Figure 1 1 Rear Panel Controls Used in Start Up 1 4 TDS 684A TDS 744A amp TDS 784A User Manual Start Up Table 1 2 Fuse and Fuse Cap Part Numbers Fuse Cap Fuse Fuse Part Number Part Number 0 25 inch x 1 25 inch UL 198 6 3AG 6A 159 0013 00 200 2264 00 FAST 250 V 5 mmx 20 mm IEC 127 5 A T 250 V 159 0210 00 200 2265 00 Front Cover Removal To remove the front cover grasp its left and right edges and snap it off of the front subpanel To reinstall it align it to the front subpanel and snap it back on Power On To power on the oscilloscope do the following steps 1 Check that the rear panel principal power swit
61. frame and a grid Cross Hair provides cross hairs and a frame Frame displays just a frame NTSC provides a grid useful for measuring NTSC class waveforms PAL provides a grid useful for measuring PAL class waveforms NOTE Selecting either NTSC or PAL graticules automatically changes the vertical scale position settings coupling and sets to zero any vertical offset of any channel displayed These settings are not restored after switching to other graticule types Therefore you might want to recall the factory setup or other stored setup after selecting a different graticule Select the Format The oscilloscope displays waveforms in either of two formats YT and XY To set the display axis format TDS 684A Press DISPLAY Format main gt XY or YT side TDS 700A models Press DISPLAY Mode main gt Normal pop up gt Format RO main gt XY or YT side TDS 684A TDS 744A amp TDS 784A User Manual 3 31 Acquiring and Displaying Waveforms YT is the conventional oscilloscope display format It shows a signal voltage the vertical axis as it varies over time the horizontal axis Ene gt XY format compares the voltage levels of two waveform records point by point That is the oscilloscope displays a graph of the voltage of one waveform record against the voltage of another waveform record This mode is particularly useful for studying phase relationships
62. gated You must turn gating off in the Gating side menu NOTE Cursors are displayed relative to the selected waveform If you are making a measurement using two waveforms this behavior can be a source of confusion If you turn off horizontal locking and adjust the horizontal position of one waveform independent of the other the cursors appear at the requested position with respect to the selected waveform Gated measurements remain accurate but the displayed positions of the cursors change when you change the selected waveform oe 5 Tek Run 100kS 5 Sample AS 2 72ms 1 77ms Chi Brstwd 2 039ms i Gate with V Bar Cursors mY M SO0Ms chi 7 252mv re FOYER a TOE PPETT POTTED Remove Gating Reference Measrmnt setup for cht a o ET ee Ooo CIC IC IC S C O Figure 3 54 Measure Menu Gating The oscilloscope provides two settings histogram and min max for specifying how measure determines the High and Low levels of waveforms To use the high low setup do the following step Press MEASURE gt High Low Setup main gt Histogram or Min Max side If you select Min Max you may also want to check and or revise values using the Reference Levels main menu TDS 684A TDS 744A amp TDS 784A User Manual Measuring Waveforms Histogram sets the values statistically It selects the most common val
63. gt Trigger side Trigger Menu Each trigger type edge logic and pulse has its own main trigger menu which is described as each type is discussed in this section To select the trigger type press TRIGGER MENU gt Type main gt Edge Logic or Pulse pop up Triggering on a Waveform Edge The TDS Oscilloscope can trigger on an edge of a waveform An edge trigger event occurs when the trigger source passes through a specified voltage level in a specified direction the trigger slope You will likely use edge triggering for most of your measurements This subsection describes how use edge trigger ing how to select edge type source coupling slope and level It also details how to select trigger mode auto or normal for all trigger types To Check Edge To quickly check if edge triggers are selected check the Trigger readout When Trigger Status edge triggers are selected the trigger readout displays the trigger source as well as the trigger slope and level See Figure 3 36 Main Trigger Slope Rising Edge Main Trigger Source Ch 1 Main Time Base Time Div Main Trigger Level Main Time Base m 2o mva CF M 500us Chif ode coupling amp ue Holdoff TYPE Source lt Edge gt Chi 109019 11 Figure 3 36 Edge Trigger Readouts TDS 684A TDS 744A amp TDS 784A User Manual 3 57 Triggering on Waveforms To
64. indicates the level set by the delayed trigger system 11 Press Level main gt Level Set to TTL Set to ECL or Set to 50 side Level lets you enter the delayed trigger level using the general purpose knob or the keypad Set to TTL fixes the trigger level at 1 4 V Set to ECL fixes the trigger level at 1 3 V Set to 50 fixes the delayed trigger level to 50 of the peak to peak value of the delayed trigger source signal NOTE When you set the Vertical SCALE smaller than 200 mV the oscilloscope reduces the Set to TTL or Set to ECL trigger levels below standard TTL and ECL levels That happens because the trigger level range is fixed at 12 divisions from the center At 100 mV the next smaller setting after 200 mV the trigger range is 1 2 V which is smaller than the typical TTL 1 4 V or ECL 1 3 V level TDS 684A TDS 744A amp TDS 784A User Manual 3 85 Triggering on Waveforms 3 86 TDS 684A TDS 744A amp TDS 784A User Manual E SS _ eee Measuring Waveforms To make the best use of the TDS Oscilloscope when taking measurements you need to know how to use the three types or classes of measurements it can take This section describes how to take the following classes of measurements Fig ure 3 51 shows all three measurement classes m Automated for automatically taking and displaying waveform measurements m Cursor for measuring the difference either in time or voltage between two locati
65. labeled factory have the factory setup stored as a default and can be used to store current setups without disturbing previously stored setups A CAUTION Setup locations in the side menu appear with the label user if they 2 24 TDS 684A TDS 744A amp TDS 784A User Manual Tutorial Tek Run 100kKS 5 Sample A Save Current Setup uJ To File To Setup1 user To Setup 2 factory To Setup3 factory 1of3 ch 200mv 100mY M 500ys chi 248mV more acai aati Tecan eo VERE LEETS Saved Current Factory Utilities Setup Setu Setup DIG IOC IC IC Figure 2 18 Save Recall Setup Menu 7 Press one of the To Setup side menu buttons to store the current instrument settings into that setup location Remember which setup location you selected for use later There are more setup locations than can be listed at one time in the side menu The more side menu item gives you access to all the setup locations Once you have saved a particular setup you can change the settings as you wish knowing that you can come back to that setup at any time 8 Press MEASURE gt Positive Width side to add that measurement to the display Recall a Setup To recall the setup press SAVE RECALL SETUP gt Recall Saved Set up main gt Recall Setup side for the setup location you used in the last exe
66. line help system This section describes how to use the following two features m Status which displays a snapshot of system display trigger waveform and I O settings Help which displays a screen of brief information about each oscilloscope control when that control is operated Press SHIFT STATUS gt Status main gt System Display Trigger Waveforms or I O side System displays information about the Horizontal Zoom Acquisition Measure and Hardcopy systems See Figure 3 79 This display also tells you the firmware version Display provides parameter information about the display and color systems Trigger displays parameter information about the triggers Waveforms displays information about waveforms including live math and reference waveforms T O displays information about the I O port s To display the banner lists firmware version options copyright and patents Press SHIFT STATUS Banner main See Figure 3 80 TDS 684A TDS 744A amp TDS 784A User Manual 3 133 Determining Status and Accessing Help ie R Tek Run 100kS 5 Sample F Firmware Version Status i Scale rows srg Fos Rec Lngth Pos Snapshot Main 50 yus Main 50 500 1Odivs 50 0 Diyd Says Runs After t6ns z 5 rerti Horizont OFF LG LG System Mode stop Sample R S bution Display Limit Test State Hardcopy Bell chi ch2 ch3 chg OFF OFF OFF Refi None None None
67. m Expand the waveform horizontally on screen Select the source channel and increase the horizontal scale using the horizontal SCALE knob For instance if you display the source waveform illustrated in Figure 3 95 on page 3 163 so its rising and falling edges are displayed over more horizontal divisions the amplitude of the corresponding derivative pulse will decrease Whichever method you use be sure Zoom is off and the zoom factors are reset see Using Zoom below Once you have your waveform optimally displayed you can also magnify or contract it vertically and horizontally to inspect any feature Just be sure the differentiated waveform is the selected waveform Press MORE then select the differentiated waveform in the More main menu Then use the Vertical and Horizontal SCALE knob to adjust the math waveform size If you wish to see the zoom factor 2X 5X etc you need to turn zoom on press ZOOM gt ON side The vertical and horizontal zoom factors appear on screen Whether zoom is on or off you can press Reset Zoom Factors side to return the zoomed derivative waveform to no magnification The Advanced DSP Math capabilities of the TDS Oscilloscope include waveform integration This capability allows you to display an integral math waveform that is an integrated version of the acquired waveform This section describes how to setup the oscilloscope to display and measure integral math waveforms Integral waveforms
68. not the divisions of the video graticules For NTSC the actual grid lines represent 10 IRE and for PAL the lines are 100 mV apart To measure the time of a waveform repeat the process just described but count the horizontal divisions and multiply by the horizontal scale factor For example if you count five major vertical graticule divisions for one waveform cycle at a horizontal scale factor of 50 uS division then you can easily calculate the waveform period as 5 divisions x 50 wS division 250 us or 4 kHz Optimizing Measurement Accuracy SPC and Probe Cal 3 102 Signal Path Compensation The TDS Oscilloscope provides two features that optimize measurement accuracy Signal Path Compensation SPC lets you compensate the internal signal path used to acquire the waveforms you acquire and measure based on the ambient temperature Probe Cal lets you compensate the entire signal path from probe tip to digitized signal to improve the gain and offset accuracy of the probe This section tells you how to use both features The TDS Oscilloscope lets you compensate the internal signal path used to acquire the waveforms you measure SPC optimizes the oscilloscope capability to make accurate measurements based on the ambient temperature TDS 684A TDS 744A amp TDS 784A User Manual Measuring Waveforms Run an SPC anytime you wish to ensure that the measurements you make are made with the most accuracy possible You should als
69. or frequency Paired cursors measure both vertical parameters typically volts and horizontal parameters typically time simultaneously Look at Figure 3 58 Note that each of the two paired cursors has a long vertical bar paired with an X The Xs measures vertical parameters typically volts the long vertical bars measure horizontal parameters typically time or frequency See Cursor Readouts on page 3 98 for more information TDS 684A TDS 744A amp TDS 784A User Manual 3 97 Measuring Waveforms 3 98 Cursor Modes Independent Mode NOTE When cursors measure certain math waveforms the measurement may not be of time frequency or voltage Cursor measurement of those math waveforms that are not of time frequency or voltage is described in Waveform Math which begins on page 3 142 There are two cursor modes independent and tracking See Figure 3 59 In independent mode you move only one cursor at a time using the general purpose knob The active or selected cursor is a solid line Press SELECT to change which cursor is selected In tracking mode you normally move both cursors in tandem using the general purpose knob The two cursors remain a fixed distance time or voltage from each other Press SELECT to temporarily suspend cursor tracking You can then use the general purpose knob to adjust the distance of the solid cursor relative to the dashed cursor A second push toggles the cursors back to
70. or the histogram method With the min max method most useful for general waveforms it is the maximum value found With the histogram method most useful for pulses it refers to the most common value found above the mid point See Appendix B Algorithms for details Holdoff trigger A specified amount of time after a trigger signal that elapses before the trigger circuit will accept another trigger signal Trigger holdoff helps ensure a stable display a Horizontal bar cursors The two horizontal bars that you position to measure the voltage parameters of a waveform The oscilloscope displays the value of the active moveable cursor with respect to ground and the voltage value between the bars Interpolation The way the oscilloscope calculates values for record points when the oscilloscope cannot acquire all the points for a complete record with a single trigger event That condition occurs when the oscilloscope is limited to real time sampling and the time base is set to a value that exceeds the effective sample rate of the oscilloscope The oscilloscope has two interpolation options linear or sin x x interpolation Linear interpolation calculates record points in a straight line fit between the actual values acquired Sin x x computes record points in a curve fit between the actual values acquired It assumes all the interpolated points fall in their appropriate point in time on that curve Intensity Display brightness InstaVu
71. scale However if you select Holdoff as opposed to Default Holdoff the time set in the Holdoff menu item is used at all horizontal scale settings To select the slope that the edge trigger will occur on 1 Press the TRIGGER MENU Type main gt Edge pop up gt Slope main 2 Select the rising or falling edge from the side menu Press the TRIGGER MENU gt Type main gt Edge pop up gt Level main Level Set to TTL Set to ECL or Set to 50 side Level lets you enter the trigger level using the general purpose knob or the keypad Set to TTL fixes the trigger level at 1 4 V Set to ECL fixes the trigger level at 1 3 V NOTE When you set the volts div smaller than 200 mV the oscilloscope reduces the Set to TTL or Set to ECL trigger levels below standard TTL and ECL levels This reduction occurs because the trigger level range is fixed at 12 divisions from the center At 100 mV the next smaller setting after 200 mV the trigger range is 1 2 V which is smaller than the typical TTL 1 4 V or ECL 1 3 V level Set to 50 fixes the trigger level to approximately 50 of the peak to peak value of the trigger source signal Triggering Based on Logic 3 60 The TDS Oscilloscope can trigger on a logic or binary pattern and on the state of a logic pattern at the time it is clocked It can also trigger on data that violates TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Wavefo
72. screen will be removed after a few seconds If the self test fails call your local Tektronix Service Center Depending on the type of failure you may still be able to use the oscilloscope before it is serviced To power off the oscilloscope toggle the ON STBY switch TDS 684A TDS 744A amp TDS 784A User Manual D Overview This chapter describes the basic concepts of operating the TDS Oscilloscope Understanding the basic concepts of your oscilloscope will help you use it much more effectively The first section Operating Interface Maps quickly shows you how the oscilloscope controls are organized and where you can read about them It also illustrates the general procedures for operating the menu system This section includes the titles m Front Panel Map m Rear Panel Map m Display Map m To Operate a Menu m To Operate a Pop Up Menu The second section Tutorial contains example procedures that lead you through the fundamental tasks needed to display a waveform measurement It also includes an example procedure that teaches you how to store a setup of the oscilloscope controls for later use This section includes the following tuto rial examples m Setting Up for the Examples m Example 1 Displaying a Waveform m Example 2 Displaying Multiple Waveforms m Example 3 Taking Automated Measurements m Example 4 Saving Setups To explore these topics in more depth and to read about topics not covered in this sec
73. side D 10 Wait for gain compensation to complete one to three minutes TDS 684A TDS 744A amp TDS 784A User Manual 3 105 Measuring Waveforms 3 106 When gain compensation completes the following actions occur The clock icon will disappear If offset compensation is required for the probe installed the Probe Offset Compensation message will replace the Probe Gain Compensa tion message If gain compensation did not complete successfully you may get a Probe is not connected message examine the probe connections to the digitizing oscilloscope be sure the probe tip is properly installed in its retractor etc and repeat step 9 If gain compensation did not complete successfully you may get the message Compensation Error This error implies that the probe gain 2 error and or offset 50 mV is too great to be compensated You can substitute another probe and continue Have your probe checked by service personnel Tek Run 100kKS 5 Sample 4 Probe Gain Compensation 1 Connect probe to front panel signal outputs labeled Probe Compensation SIGNAL and GND 2 Press Compensate Gain to proceed Press Clear Menu to exit OK Compensate Gain Position Cal Probe initialized I 1 1911 a 11 Figure 3 63 Probe Cal Menu and Gain Compensation Display 11 If the Probe Offset Compensat
74. the following description about aliasing and the suggestions for preventing it About Aliasing When a waveform aliases it appears on screen with a frequency lower than the actual waveform being input or it appears unstable even though the light next to TRIG D is lighted Aliasing occurs because the oscilloscope cannot sample the signal fast enough to construct an accurate waveform record See Figure 3 16 TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms Actual High Frequency Waveform _ gt Apparent Low frequency Waveform Due to Aliasing Sampled P oints Figure 3 16 Aliasing Methods to Check and Eliminate To quickly check for aliasing slowly increase the horizontal scale time per division setting If the shape of the displayed waveform changes drastically or becomes stable at a faster time base setting your waveform was probably aliased To avoid aliasing be sure to sample the input signal at a rate more than twice as fast as the highest frequency component For example a signal with frequency components of 500 MHz would need to be sampled at a rate faster than 1 Gigasamples second to represent it accurately and avoid to aliasing The following tips may help you eliminate aliasing on a signal m Try adjusting the horizontal scale m Try pressing the AUTOSET button m Try switching the acquisition mode in the acquisition menu to Envelope all three TDS models
75. the menu selection will not change Hi Res Mode TDS 700A models only Hi Res mode averages all samples taken during an acquisition interval to create a record point The average results in a higher resolution lower bandwidth waveform A key advantage of Hi Res is its potential for increasing resolution regardless of the input signal Table 3 3 and the equations shown below illustrate how you can obtain up to 15 significant bits with Hi res mode Note that the resolution improvements are limited to speeds slower than 100 ns div Also resolutions above 15 bits are not allowed by internal hardware and computation limitations Si Sampling Interval for TDS 744A I ns _ Time Div _ Spus Div _ ASRAON Number Of Points Div 50 Points Div au Nd Number of points per decimation interval 4 100 Resolution Enhancement bits 0 5 X LOG Nd 3 extra bits Bits of Resolution Resolution Enhancement 3 bits 8 bits 11 bits Hi Res mode only works with real time noninterpolated sampling If you set the time base so fast that it requires real time interpolation or equivalent time sampling the mode automatically becomes Sample even though the menu selection will not change Table 3 3 Additional Resolution Bits Time Base Speed Bits of Resolution 100 ns and faster 8 bits 200 ns to 500 ns 9 bits 1 us to 2 us 10 bits 5 us to 10 us 11 bits 20 us to 50 us 12 bits 100 us to 200 us 13 bits 500 us 14 bits 1 ms and slower 15 b
76. the readouts below the graticule TDS 684A TDS 744A amp TDS 784A User Manual Tutorial Example 1 Displaying a Waveform The TDS Oscilloscope provides front panel knobs for you to adjust a waveform or it can automatically set up its controls to display a waveform Do the following tasks to learn how to adjust a waveform and how to autoset the TDS Oscilloscope Adjust the Waveform The display shows the probe compensation signal It is a 1 kHz square wave of Display approximately 0 5 V amplitude Figure 2 6 shows the main VERTICAL and HORIZONTAL sections of the front panel Each has SCALE and POSITION knobs Do the following steps to adjust the size and placement of the waveform using the front panel knobs 1 Turn the vertical SCALE knob clockwise Observe the change in the displayed waveform and the channel readout at the bottom of the display EE VERTICAL A HORIZONTAL gt oO VERTICAL ZOOM HORIZONTAL Z SCALE lt SCALE gt zZ WAVEFORM OFF E Figure 2 6 The VERTICAL and HORIZONTAL Controls 2 Turn the vertical POSITION knob first one direction and then the other Observe the change in the displayed waveform Then return the waveform to the center of the graticule 3 Turn the horizontal SCALE knob one click clockwise Observe the time base readout at the bottom of the display The time base should be set to 200 us div now and you should see two complete waveform cycles on the display TDS 684A TDS 74
77. they do not show timing dynamics The TVC untangles the often confusing waveforms and delivers a coherent real time view The TVC adds three measurement functions to the voltage versus time capability of your oscilloscope time delay versus time pulse width versus time and period versus time TDS 684A TDS 744A amp TDS 784A User Manual E 5 Appendix E Probe Selection E 6 TDS 684A TDS 744A amp TDS 784A User Manual Glossary ACM AC coupling A type of signal transmission that blocks the DC component of a signal but uses the dynamic AC component Useful for observing an AC signal that is normally riding on a DC signal Accuracy The closeness of the indicated value to the true value Acquisition The process of sampling signals from input channels digitizing the samples into data points and assembling the data points into a waveform record The waveform record is stored in memory The trigger marks time zero in that process Acquisition interval The time duration of the waveform record divided by the record length The oscilloscope displays one data point for every acquisition interval Active cursor The cursor that moves when you turn the general purpose knob It is represented in the display by a solid line The readout on the display shows the absolute value of the active cursor Aliasing A false representation of a signal due to insufficient sampling of high frequencies or fast transitions A conditio
78. tracking Tracking Mode Only Selected Cursor Moves gt Cursor Readouts Both Cursors Move in Tandem Figure 3 59 Cursor Modes The cursor readout shows the absolute location of the selected cursor and the difference between the selected and non selected cursor The readouts differ depending on the cursor type you select H Bars V Bars or Paired H Bars The value after A shows the voltage difference between the cursors The value after shows the voltage of the selected cursor relative to ground See Figure 3 60 With the video trigger option you can also display the voltage in IRE units V Bars The value after A shows the time or frequency difference between the cursors The value after shows the time frequency of the selected cursor relative to the trigger point With the video trigger option you can also display the line number TDS 684A TDS 744A amp TDS 784A User Manual Measuring Waveforms TDS 700A Models Only In FastFrame mode the shows the time position of the selected cursor relative to the trigger point of the frame that the selected cursor is in The A shows the time difference between the two cursors only if both cursors are in the same frame Paired The value after one A shows the voltage difference between the two Xs the other A shows the time or frequency difference between the two long vertical bars The value after shows the voltage at the X of the sele
79. uses a variety of variables in its calculations These include High Low High is the value used as the 100 level in measurements such as fall time and rise time For example if you request the 10 to 90 rise time then the oscilloscope will calculate 10 and 90 as percentages with High representing 100 Low is the value used as the 0 level in measurements such as fall time and rise time The exact meaning of High and Low depends on which of two calculation methods you choose from the High Low Setup item of the Measure menu These are Min max and Histogram Min Max Method defines the 0 and the 100 waveform levels as the lowest amplitude most negative and the highest amplitude most positive samples The min max method is useful for measuring frequency width and period for many types of signals Min max is sensitive to waveform ringing and spikes however and does not always measure accurately rise time fall time overshoot and undershoot The min max method calculates the High and Low values as follows High Max and Low Min Histogram Method attempts to find the highest density of points above and below the waveform midpoint It attempts to ignore ringing and spikes when determining the 0 and 100 levels This method works well when measuring square waves and pulse waveforms TDS 684A TDS 744A amp TDS 784A User Manual B 1 Appendix B Algorithms HighRef MidRef LowRef Mid2Ref The oscilloscope
80. waveforms as opposed to reference waveforms Reset All Factors resets for all waveforms A TDS 700A Series oscilloscope can display and control a waveform that is both zoomed and unzoomed magnified and unmagnified To do so its creates two 1 2 height graticules or windows and displays the magnified waveform in the upper and the unmagnified waveform in the lower graticule To use Dual Window Zoom also called zoom preview mode do the following steps 1 Press Zoom gt Mode main gt Preview side Note that the oscilloscope displays the box enclosed area on the waveform as magnified in the top graticule See Figure 3 24 2 To scale or position the unmagnified waveform press Selected Grati cule main gt Lower side Use the vertical and horizontal knobs to scale and position the unmagnified waveform in the box Note that as you scale or move the unmagnified waveform relative to the box the oscilloscope alters the magnified display accordingly to include only the waveform portion within the box 3 To scale or position the magnified waveform press Selected Grati cule main gt Upper side Use the vertical and horizontal knobs to scale and position the magnified waveform Note that as you scale or move the magnified waveform the oscilloscope scales or moves the box relative to the unmagnified waveform so the box encloses only the waveform portion magnified in the upper graticule TDS 684A TDS 744A amp TDS 7
81. wet Rinses bine Kee S 3 56 Figure 3 36 Edge Trigger Readouts cce cess cceces 3 57 Figure 3 37 Main Trigger Menu Edge Type 3 58 Figure 3 38 Violation Zones for Setup Hold Triggering 3 63 Figure 3 39 Logic Trigger Readouts State Class Selected 3 64 Figure 3 40 Logic Trigger Menu 0 cee eee cere eens 3 65 Figure 3 41 Logic Trigger Menu Time Qualified TRUE 3 67 Figure 3 42 Triggering on a Setup Hold Time Violation 3 70 Figure 3 43 Pulse Trigger Readouts ccceececseceees 3 71 Figure 3 44 Main Trigger Menu Glitch Class 3 73 Figure 3 45 Main Trigger Menu Runt Class 3 75 TDS 684A TDS 744A amp TDS 784A User Manual Table of Contents Figure 3 46 Figure 3 47 Figure 3 48 Figure 3 49 Figure 3 50 Figure 3 51 Figure 3 52 Figure 3 53 Figure 3 54 Figure 3 55 Figure 3 56 Figure 3 57 Figure 3 58 Figure 3 59 Figure 3 60 Figure 3 61 Figure 3 62 Figure 3 63 Figure 3 64 Figure 3 65 Figure 3 66 Figure 3 67 Figure 3 68 Figure 3 69 Figure 3 70 Figure 3 71 Figure 3 72 Figure 3 73 Hardcopy Device Figure 3 74 Hardcopy Device Via a PC Figure 3 75 Figure 3 76 Figure 3 77 Figure 3 78 Figure 3 79 Figure 3 80 Figure 3 81 Figure 3 82 Main Trigger Menu Slew Rate Class Delayed Runs After Main cceceececees Delayed Triggerable How th
82. your GPIB board For example if you installed the software in the GPIB PC directory type cd GPIB PC 2 Run the IBIC program that came with your GPIB board Type IBIC 3 Type IBFIND DEV1 where DEV1 is the name for the oscilloscope you defined using the IBCONF EXE program that came with the GPIB board TDS 684A TDS 744A amp TDS 784A User Manual 3 127 Saving Waveforms and Setups NOTE If you defined another name use it instead of DEV1 Also remember that the device address of the oscilloscope as set with the IBCONF EXE program should match the address set in the oscilloscope Utility menu typically use 71 4 Type IBWRT HARDCOPY START NOTE Be sure the oscilloscope Utility menu is set to Talk Listen and not Hardcopy Talk Only or you will get an error message at this step Setting the oscilloscope Utility menu is described under Set Communication Parameters on page 3 122 5 Type IBRDF lt Filename gt where lt Filename gt is a valid DOS file name with which you want to label your hardcopy file It should be lt 8 characters long and up to a 3 character extension For example you could type ibrdf screen 6 Exit the IBIC program by typing EXIT 7 Copy the data from your file to your hardcopy device Type COPY lt Filename gt lt Output port gt lt B gt where lt Filename gt is the name you defined in step 5 and lt Output port gt is the PC output port y
83. 11 Tutorial Trigger Level Bar Trigger P osition Indicator Channel Reference Indicator Trigger Readout Time Base Readout Channel Readout The channel reference indicator shows the vertical position of channel 1 with no input signal This indicator points to the ground level for the channel when its vertical offset is set to 0 V in the vertical menu when vertical offset is not set to O V it points to the vertical offset level The trigger readout shows that the oscilloscope is triggering on channel 1 Ch1 on a rising edge and that the trigger level is about 200 300 mV The time base readout shows that the main time base is set to a horizontal scale of 500 us div The channel readout indicates that channel 1 Ch1 is displayed with DC coupling In AC coupling appears after the volts div readout The oscilloscope always displays channel at reset Tek Run 100kKS 5 Sample Recall Factory Nee cr Nor OK _1 00 M 5004S chi T 220mV a a aaa i Factory Init eca ave eca File Saved Current Factory Utilities Setup Setup Setu Dooa Figure 2 5 The Display After Factory Initialization Right now the channel time base and trigger readouts appear in the graticule area because a menu is displayed You can press the CLEAR MENU button at any time to remove any menus and to move
84. 12 Save Current Setup 3 111 user status 3 111 Save Recall WAVEFORM button 3 114 3 117 Save Recall Waveform menu 3 114 active status 3 114 Autosave 3 116 Delete Refs 3 115 empty status 3 114 File Utilities 3 117 Ref1 Ref2 Ref3 Ref4 File 3 115 Save Format 3 115 Save Waveform 3 114 Saving Waveforms 3 114 Saving and recalling setups 2 24 3 111 Saving and recalling waveforms 3 114 Saving Waveforms and Setups 3 111 Scale vertical 3 153 3 164 3 169 seconds Cursor menu 3 101 Security bracket 2 5 SELECT button 3 100 Glossary 9 Select Measrmnt Measure menu 3 90 3 94 Selected waveform Glossary 10 Self test 1 6 Serial number 2 5 Service Assurance A 5 Set 1st Source to More menu 3 143 Set 2nd Source to More menu 3 143 Set Function to More menu 3 143 Index 12 SET LEVEL TO 50 button 3 54 Set Levels in units Measure menu 3 93 Set operator to More menu 3 143 Set Single Source to More menu 3 142 3 143 Set Thresholds Main Trigger menu 3 65 3 68 Set to 10 Horizontal menu 3 16 Set to 50 Delayed Trigger menu 3 85 Set to 50 Horizontal menu 3 16 Set to 50 Main Trigger menu 3 54 3 60 3 74 Set to 90 Horizontal menu 3 16 Set to ECL Delayed Trigger menu 3 85 Set to ECL Main Trigger menu 3 60 3 74 3 78 Set to TTL Delayed Trigger menu 3 85 Set to TTL Main Trigger menu 3 60 3 74 3 78 Set to Zero Vertical menu 3 12 Set Hold Trigger 3 62
85. 3 59 Chl Ch2 3 58 3 65 3 68 3 69 3 73 3 74 3 76 3 77 Class 3 76 Pattern 3 64 Runt 3 74 Setup Hold 3 68 Slew Rate 3 77 State 3 67 Class Glitch 3 72 Clock Source 3 69 Coupling 3 58 Data Source 3 68 DC 3 58 Define Inputs 3 65 3 67 3 69 Define Logic 3 66 3 68 Delta Time 3 78 Edge 3 57 3 58 Either 3 73 3 74 3 77 Falling edge 3 68 3 69 Glitch 3 73 Goes FALSE 3 66 3 68 Goes TRUE 3 66 3 68 HF Rej 3 58 Level 3 60 3 74 3 77 LF Rej 3 58 Mode amp Holdoff 3 59 NAND 3 66 3 68 Negative 3 73 3 74 3 77 Noise Rej 3 58 NOR 3 66 3 68 Normal 3 59 OR 3 66 3 68 Polarity 3 74 3 77 Polarity and Width 3 73 Positive 3 73 3 74 3 77 Pulse 3 57 3 74 3 76 Reject Glitch 3 73 Rising edge 3 68 3 69 Runt 3 74 3 76 Set Thresholds 3 65 3 68 Set to 50 3 54 3 60 3 74 Set to ECL 3 60 3 74 3 78 Set to TTL 3 60 3 74 3 78 Slope 3 60 Source 3 58 3 73 3 74 3 76 3 77 State 3 67 3 68 Thresholds 3 75 3 78 Index 8 Trigger When 3 66 3 68 3 78 True for less than 3 66 True for more than 3 66 Type 3 57 3 58 3 76 Logic 3 64 3 67 3 68 Pulse 3 77 Pulse 3 74 Type Pulse 3 72 Width 3 73 MAIN TRIGGER OUTPUT BNC 2 5 Map Math Color menu 3 35 Map Reference Color menu 3 35 Math waveform derivative See Derivative math waveform FFT See FFT math waveform integral See Integral math wavef
86. 4A amp TDS 784A User Manual 2 13 Tutorial Autoset the Oscilloscope MAIN LEVEL Knob AUTOSET Button When you first connect a signal to a channel and display it the signal displayed may not be scaled and triggered correctly Use the autoset function and you should quickly get a meaningful display You should have a stable display of the probe compensation waveform from the last step Do the following steps to first create an unstable display and then to autoset the display 1 To create an unstable display slowly turn the trigger MAIN LEVEL knob see Figure 2 7 first one direction and then the other Observe what happens when you move the trigger level above the highest part of the waveform Leave the trigger level in that untriggered state 44 TRIGGER MAIN LEVEL TRIG D READY DELAYED TRIG arm TRIGGER MENU SET LEVEL TO 50 Figure 2 7 TRIGGER Controls 2 Press AUTOSET see Figure 2 8 and observe the stable waveform display SAVE RECALL ACQUIRE MENU APPLICATION MENU AUTOSET_ WAVEFORM MEASURE HARDCOPY RUN STOP_ STATUS UTILITY SHIFT C HELP CURSOR DISPLAY E E A VERTICAL A HORIZONTAL ye Figure 2 8 AUTOSET Button Location TDS 684A TDS 744A amp TDS 784A User Manual Tutorial Figure 2 9 shows the display after pressing AUTOSET If necessary you can adjust the waveform now by using the knobs discussed earlier in this example
87. 4A amp TDS 784A User Manual 3 103 Measuring Waveforms 3 104 Probe Cal Tek Run 5 00GS 5 Sample 4 Signal Path ompensatio EEA AAEE ee OPA PEDA A EEE AEE A signal Path Compensation SPC corrects for DC inaccuracies caused by temperature variations and or long term drift SPC can be run any time after the oscilloscope is RET and should be run whenever the oscilloscope s ambient temperature has changed by more than 5 C or once a week if vertical settings of 5mV div or less are used y Input signals OK with AC components Disconnect or otherwise remove these signals prior to running SPC Compensate SPC will take 15 minutes to run Signal Paths oltage Frequency ulse system Path Reference Response Trigger lt Cal gt Pass Pass Pass Pass Oooo oj I 19 19 M Figure 3 62 Performing a Signal Path Compensation The TDS Oscilloscope lets you compensate the probe based on the channel it is connected to to improve the gain and offset accuracy of the probe By executing Probe Cal on a channel with its probe installed you can optimize the oscillo scope capability to make accurate measurements using that channel and probe Run a Probe Cal anytime you wish to ensure that the measurements you make are made with the most accuracy possible You should also run a Probe Cal if you have changed to a different prob
88. 5 on FFT math waveforms 3 154 on integral math waveforms 3 169 ZOOM button 3 38 Zoom feature 3 37 Zoom menu Dual Zoom 3 41 Dual Zoom Offset 3 41 Horizontal Lock 3 39 Preview 3 40 Reset Zoom Factors 3 40 Zoom Off 3 40 Zoom Off Zoom menu 3 40 Index 15 Index Index 16 TDS 684A TDS 744A amp TDS 784A User Manual
89. 500 points Therefore FFT math waveforms of 500 point waveforms are always zoomed 2X or more with interpolation Waveforms with other record lengths can be zoomed or not and can have minimum Zooms of 1X or less TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications Sin x x interpolation may distort the magnitude and phase displays of the FFT depending on which window was used You can easily check the effects of the interpolation by switching between sin x x and linear interpolation and observing the difference in measurement results on the display If significant differences occur use linear interpolation Undersampling Aliasing Aliasing occurs when the oscilloscope acquires a source waveform with frequency components outside of the frequency range for the current sample rate In the FFT waveform the actual higher frequency components are under sampled and therefore they appear as lower frequency aliases that fold back around the Nyquist point See Figure 3 92 The greatest frequency that can be input into any sampler without aliasing is 4 the sample frequency Since source waveforms often have a fundamental frequency that does not alias but have harmonic frequencies that do you should have methods for recognizing and dealing with aliases m Be aware that a source waveform with fast edge transition times creates many high frequency harmonics These harmonics typically decrease in ampl
90. 7 Choosing an Acquisition Mode Sampling and Digitizing 3 16 The TDS Oscilloscopes are digital products that can acquire and process your input signal in a variety of modes To help you choose the best mode to use for your signal measurement task this subsection first describes m How the oscilloscope samples and digitizes an input signal m How the different acquisition modes such as interpolation affect this process m How to select among these modes Following these descriptions are procedures for selecting the sampling and acquisition modes beginning with Checking the Acquisition Readout on page 3 23 Acquisition is the process of sampling the analog input signal digitizing it to convert it into digital data and assembling it into a waveform record See Figure 3 9 The oscilloscope creates a digital representation of the input signal by sampling the voltage level of the signal at regular time intervals The sampled and digitized points are stored in memory along with corresponding timing information You can use this digital representation of the signal for display measurements or further processing TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms i i oo fo Sica T 1 oV n i j A X ia x 5 0 V 50V Input Signal Sampled Points Digital Values Figure 3 9 Acquisition Input Analog Signal Sample and Digitize The oscilloscope uses the samples it takes see Figure 3 11 to cre
91. 784A User Manual Glossary Cycle area A measurement of waveform area taken over one cycle Expressed in volt seconds Area above ground is positive area below ground is negative Cycle mean An amplitude voltage measurement of the arithmetic mean over one cycle Cycle RMS The true Root Mean Square voltage over one cycle DC coupling A mode that passes both AC and DC signal components to the circuit Available for both the trigger system and the vertical system Delay measurement A measurement of the time between the middle reference crossings of two different waveforms Delay time The time between the trigger event and the acquisition of data Digitizing The process of converting a continuous analog signal such as a waveform to a set of discrete numbers representing the amplitude of the signal at specific points in time Digitizing is composed of two steps sampling and quantizing Display system The part of the oscilloscope that shows waveforms measurements menu items status and other parameters Edge Trigger Triggering occurs when the oscilloscope detects the source passing through a specified voltage level in a specified direction the trigger slope Envelope acquisition mode A mode in which the oscilloscope acquires and displays a waveform that shows the variation extremes of several acquisitions Equivalent time sampling ET TDS 700A Models Only A sampling mode in which the oscilloscope acquires
92. 83 Acquire Menu Create Limit Test Template Figure 3 84 More Menu cece cece cece cece erences Figure 3 85 Dual Waveform Math Main and Side Menus Figure 3 86 System Response to an Impulse 0065 Figure 3 87 Define FFT Waveform Menu eeeee0e Figure 3 88 FFT Math Waveform in Math 66 Figure 3 89 Cursor Measurement of an FFT Waveform Figure 3 90 Waveform Record vs FFT Time Domain Record Figure 3 91 FFT Time Domain Record vs FFT Frequency Domain Record eeeeeeeceeee Figure 3 92 How Aliased Frequencies Appear in an FFT Figure 3 93 Windowing the FFT Time Domain Record Figure 3 94 FFT Windows and Bandpass Characteristics Figure 3 95 Derivative Math Waveform eeeeeeeeee Figure 3 96 Peak Peak Amplitude Measurement of a Derivative Waveform cece cece cece cece eee sees Figure 3 97 Integral Math Waveform ececeeeeeees Figure 3 98 H Bars Cursors Measure an Integral Math Waveform Figure B 1 MCross Calculations 0 cece cece eee eeee Figure B 2 Fall Time scree ire eis enana ee i sale sietee o s ore E Figure B 3 Rise Time 0 cc cece cece eee cece eee eeee Figure B 4 Choosing Minima or Maxima to Use for Envelope Measurements ccc ccc s ccs c ces cceneces Figure E 1 Typical High Voltage Probes 0eeeeee Figure E
93. 84A User Manual Acquiring and Displaying Waveforms Zoomed Magnified Waveforms Nonzoomed Waveforms with Box Indicators at Corners Denoting the Selected Graticule Dual Zoom a Waveform TDS 700A Models Only To Set Dual Zoom Offset In Dual Window Zoom mode the oscilloscope does not display the zoom magnification factors however it does display the scale factors volts divi sion and time division for the zoomed waveform Tek Run MARRS sample zoom Mode off al rut E Preview ih i boheme a 25045 DZ Offset 2 500mS ic ri q domy S EE ETENE E soaps thi F l ov OIIO Selecta Graticule tower 119 109 1 1 1 Figure 3 24 Dual Window Preview Mode To select Dual Zoom press ZOOM Mode main gt Dual Zoom side to toggle it to ON See Figure 3 25 Dual zoom displays a second zoomed view of the selected unzoomed waveform The second zoomed view is offset in time from the first zoomed view Also zoom must be enabled side menu set to On or Preview to see the Dual Zoom displays To set the offset in time of the second zoomed waveform from the first press ZOOM gt Mode main gt Dual Zoom Offset side Then turn the general purpose knob or use the keypad to set the offset Dual Zoom offset is always positive The oscillosc
94. A amp TDS 784A User Manual ar ar Appendix E Probe Selection The TDS Oscilloscope can use a variety of Tektronix probes for taking different kinds of measurements To help you decide what type of probe you need this section introduces the five major types of probes passive active current optical and time to voltage probes See Appendix A Options and Accessories for a list of the optional probes available see your Tektronix Products Catalog for more information about a given probe Tektronix ships the P6139A passive probe with the TDS 744A Oscilloscope as a standard accessory The TDS 684A and TDS 784A Oscilloscopes ship without standard probes but Tektronix recommends you order the P6245 active probe to take advantage of the 1 GHz bandwidth of these two oscilloscopes NOTE The TDS 744A comes with four P6139A passive probes The TDS 684A and TDS 784A Oscilloscopes come without probes but for general purpose measurements and to take advantage of the wide bandwidth of these two oscilloscopes the P6245 Active Probe is recommended This manual lists the P6245 optional accessory probe in Appendix A Options and Accessories Passive Voltage Probes Passive voltage probes measure voltage They employ passive circuit compo nents such as resistors capacitors and inductors There are three common classes of passive voltage probes m General purpose high input resistance m Low impedance Zo m High voltage General Purpose
95. C CO Figure 3 86 System Response to an Impulse To Create an FFT To obtain an FFT of your waveform do the following steps 1 2 3 146 Connect the waveform to the desired channel input and select that channel Adjust the vertical and horizontal scales and trigger the display or press AUTOSET The topic Offset Position and Scale on page 3 153 provides in depth information about optimizing your setup for FFT displays Press MORE to access the menu for turning on math waveforms Select a math waveform Your choices are Math1 Math2 and Math3 main If the selected math waveform is not FFT press Change Math Definition side gt FFT main See Figure 3 87 Press Set FFT Source to side repeatedly until the channel source selected in step 1 appears in the menu label TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications Tek Run 50 0MS s Sample Define FFT Waveform Set FFT Source to chi Set FFT Vert Scale to dBV RMS Set FFT Window to Select the type of Math function to define from Hanning the bottom row of bezel buttons Define the new function using the side buttons ate When you are satisfied with the selections press amplitudes lt Create Math wfm 3dB Press CLEAR MENU to return to the More menu without creating a Math waveform OK Create Math wim LOO ID ICID
96. Clock Source Main Trigger menu 3 69 Collision Contrast Color menu 3 36 Color 3 33 3 48 How to set 3 33 3 48 Color Matches Contents Color menu 3 35 3 36 Color menu 3 33 Bold 3 34 Change Colors 3 34 Collision Contrast 3 36 Color 3 34 3 35 3 36 TDS 684A TDS 744A amp TDS 784A User Manual Index Color Matches Contents 3 35 3 36 Hardcopy 3 34 Hue 3 34 Lightness 3 34 Map Math 3 35 Map Reference 3 35 Math 3 35 Monochrome 3 34 Normal 3 34 Options 3 36 Palette 3 33 Persistence Palette 3 34 Ref 3 36 Reset All Mappings To Factory 3 36 Reset All Palettes To Factory 3 36 Reset Current Palette To Factory 3 36 Reset to Factory Color 3 34 Restore Colors 3 36 Saturation 3 35 Spectral 3 34 Temperature 3 34 View Palette 3 34 Color Color menu 3 34 3 35 3 36 Color Display menu 3 33 Compare Ch1 to Acquire menu 3 140 Compare Ch2 to Acquire menu 3 140 Compare Ch3 to Acquire menu 3 140 Compare Ch4 to Acquire menu 3 140 Compare Math1 to Acquire menu 3 140 Compare Math2 to Acquire menu 3 140 Compare Math3 to Acquire menu 3 140 Compensation of passive probes 3 3 Configure Utility menu 3 122 3 131 Confirm Delete File Utilities menu 3 120 Connector AUX TRIGGER INPUT 2 5 Centronics 2 5 DELAYED TRIGGER OUTPUT 2 5 GPIB 2 5 3 130 MAIN TRIGGER OUTPUT 2 5 Power 2 5 RS 232 2 5 SIGNAL OUTPUT 2 5
97. DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE TEKTRONIX RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES German Postal Information Certificate of the Manufacturer Importer We hereby certify that the TDS 684A TDS 744A and TDS 784A Digitizing Oscilloscopes and all factory installed options comply with the RF Interference Suppression requirements of Postal Regulation Vfg 243 1991 amended per Vfg 46 1992 The German Postal Service was notified that the equipment is being marketed The German Postal Service has the right to re test the series and to verify that it complies TEKTRONIX Bescheinigung des Herstellers Importeurs Hiermit wird bescheinigt da das TDS 684A TDS 744A and TDS 784A Digitizing Oscilloscopes und alle fabrikinstallierten Optionen in bereinstimmung mit den Bestimmungen der Amtsblatt Verf gung Vfg 243 1991 und Zusatzverfiigung 46 1992 funkentst rt sind Der Deutschen Bundespost wurde das Inverkehrbringen dieses Ger tes angezeigt und die Berechtigung zur berpr fung der Serie auf Einhalten der Bestimmungen einger umt TEKTRONIX NOTICE to the user operator
98. Defaults Cont Control Logic trigger triggers when pattern and state Changed by Factory Init to Goes TRUE Main trigger holdoff time Default Holdoff Selected 5 horizontal divisions Holdoff Mode Selected 250 ns Measure Delay to Measure Delay edges Measure Gating Main trigger holdoff mode Default Holdoff Main trigger mode Auto Main trigger type Edge Math definition Ch1 Ch2 Math1 extended processing No extended processing Math2 definition FFT of Chl Math2 extended processing No extended processing Math3 definition Inv of Ch1 Math3 extended processing No extended processing Channel 1 Ch1 Both rising and forward searching Off Measure High Low Setup Histogram Measure High Ref 90 and 0 V units Measure Low Ref 10 and 0 V units Measure Mid Ref 50 and 0 V units Measure Mid2 Ref 50 and 0 V units Pulse glitch filter state On Accept glitch Pulse glitch trigger polarity Positive Pulse glitch width 2 0 ns Pulse runt high threshold 12V Pulse runt low threshold 0 8 V Pulse runt trigger polarity Positive Pulse runt width 2 0 ns Pulse runt triggers when Occurs Pulse slew rate Delta Time 2 0 ns Pulse slew rate polarity Positive TDS 684A TDS 744A amp TDS 784A User Manual Appendix D Factory Initialization Settings Table D 1 Factory Initialization Defaults Cont Control Pulse slew rate thresholds Upper Lower Pulse
99. Definition i_ Glitch positive Triggering occurs if the oscilloscope detects positive spike widths less than the specified glitch time Glitch negative Triggering occurs if the oscilloscope detects negative spike widths less than the specified glitch time nay Glitch either Triggering occurs if the oscilloscope detects positive or negative widths less than the specified glitch time TDS 684A TDS 744A amp TDS 784A User Manual 3 71 Triggering on Waveforms Table 3 8 Pulse Trigger Definitions Cont Name Runt positive Runt negative Definition Triggering occurs if the oscilloscope detects a positive pulse that crosses one threshold going positive but fails to cross a second threshold before recrossing the first going negative Triggering occurs if the oscilloscope detects a negative going pulse that crosses one threshold going negative but fails to cross a second threshold before recrossing the first going positive Runt either Triggering occurs if the oscilloscope detects a positive or negative going pulse that crosses one threshold but fails to cross a second threshold before recrossing the first Width positive Width negative Triggering occurs if the oscilloscope finds a positive pulse with a width between or optionally outside the user speci fied lower and upper time limits Triggering occurs if the oscilloscope finds a negative pulse with a width betwe
100. Do Not Operate in Explosive Atmosphere Keep Probe Surface Clean Review the following safety precautions to avoid injury and prevent damage to this product or any products connected to it Only qualified personnel should perform service procedures To avoid fire hazard use only the power cord specified for this product To avoid electric shock or fire hazard do not apply a voltage to a terminal that is outside the range specified for that terminal This product is grounded through the grounding conductor of the power cord To avoid electric shock the grounding conductor must be connected to earth ground Before making connections to the input or output terminals of the product ensure that the product is properly grounded To avoid electric shock or fire hazard do not operate this product with covers or panels removed To avoid fire hazard use only the fuse type and rating specified for this product To avoid electric shock do not operate this product in wet or damp conditions To avoid injury or fire hazard do not operate this product in an explosive atmosphere To avoid electric shock and erroneous readings keep probe surface clean Product Damage Precautions Use Proper Power Source Do not operate this product from a power source that applies more than the voltage specified TDS 684A TDS 744A amp TDS 784A User Manual ix General Safety Summary Provide Proper Ventilation Do Not Operate With Suspec
101. FFT length jis the square root of 1 The resulting waveform is a display of the magnitude or phase angle of the various frequencies the waveform contains with respect to those frequencies For example Figure 3 86 shows the untransformed impulse response of a system in channel 2 at the top of the screen The FFT transformed magnitude and phase appear in the two math waveforms below the impulse The horizontal scale for FFT math waveforms is always expressed in frequency per division with the beginning left most point of the waveform representing zero frequency DC The FFT waveform is based on digital signal processing DSP of data which allows more versatility in measuring the frequency content of waveforms For example DSP allows the oscilloscope to compute FFTs of source waveforms that must be acquired based on a single trigger making it useful for measuring the frequency content of single events DSP also allows the phase as well as the magnitude to be displayed TDS 684A TDS 744A amp TDS 784A User Manual 3 145 Using Features for Advanced Applications Normal Waveform of an Tek Stopped 820 Acquisitions T i Mdth3 Zoom 0 5X Ve Impulse Response FFT Waveform of the Magnitude Response FFT Waveform of the Phase Response LOJO C C O Ch 250m V Maths 90 0 2 50kHz M 500ns Chis 2 52 V MIDI CIO O
102. FFTs These record lengths do not allow easy alignment of the zero reference point for phase measurements m Trigger on the input impulse Adjust Phase Suppression Your source waveform record may have a noise component with phase angles that randomly vary from pi to pi This noise could make the phase display unusable In such a case use phase suppression to control the noise You specify the phase suppression level in dB with respect to 1 Vrms If the magnitude of the frequency is greater than this threshold then its phase angle will be displayed However if it is less than this threshold then the phase angle will be set to zero and be displayed as zero degrees or radians The waveform reference indicator at the left side of the graticule indicates the level where phase is zero for phase FFTs It is easier to determine the level of phase suppression you need if you first create a frequency FFT math waveform of the source and then create a phase FFT waveform of the same source Do the following steps to use a cursor measurement to determine the suppression level 1 Do steps 1 through 7 of To Create an FFT that begins on page 3 146 Select dBV RMS side for the Set FFT Vert Scale to side 2 Press CURSOR Mode main gt Independent side gt Func tion main gt H Bars side Use the general purpose knob to align the selected cursor to a level that places the tops of the magnitudes of frequen cies of interest above th
103. Hardcopy 3 120 The labeling menu should appear Turn the general purpose knob or use the main menu arrow keys to select each letter Press Enter Char from the main menu to enter each letter When you have entered the name press the side menu OK Accept item See Figure 3 69 To turn on or off the confirm delete message toggle the side menu Confirm Delete button When the confirm delete option is OFF the oscilloscope can immediately delete files or directories When the confirm option is ON the oscilloscope warns you before it deletes files and gives you a chance to reconsider To turn on or off the file overwrite lock toggle the side menu Overwrite Lock button When overwrite lock is on the oscilloscope will not permit you to write over an existing file of the same name An important reason to allow overwriting is to let you write files using a target file name that contains wild card characters This means the oscilloscope creates sequential files whose names are similar except for the sequential numbers that go in the real name in the place of the question marks To format a 720 Kbyte or 1 44 Mbyte disk turn the general purpose knob until it scrolls the cursor over the name of the drive to format in fd0 Then press the side menu Format button See Saving and Recalling Setups on page 3 111 See Saving and Recalling Waveforms on page 3 114 See Printing a Hardcopy on page 3 120 The TDS Oscilloscope can pr
104. Manual xi General Safety Summary xii TDS 684A TDS 744A amp TDS 784A User Manual Preface Related Manuals This is the User Manual for the TDS 684A TDS 744A and TDS 784A Digitizing Oscilloscopes The chapter Getting Started briefly describes the TDS Oscilloscope prepares you to install it and tells you how to put it into service The chapter Operating Basics covers basic principles of the operation of the oscilloscope The operating interface illustrations and the tutorial examples rapidly help you understand how your oscilloscope operates The chapter Reference teaches you how to perform specific tasks See page 3 1 for a complete list of operating tasks covered in that chapter The Appendices provide an options listing an accessories listing and other useful information The following documents are related to the use or service of the oscilloscope m The TDS Family Digitizing Oscilloscopes Programmer Manual Tektronix part number 070 8709 xx describes using a computer to control the oscilloscope through the GPIB interface m The TDS 684A TDS 744A amp TDS 784A Reference Tektronix part number 070 8999 xx gives you a quick overview of how to operate the oscilloscope m The TDS 684A TDS 744A amp TDS 784A Performance Verification and Specifications Tektronix part number 070 8990 xx tells how to verify the performance of the oscilloscope and lists its specifications m The TDS Family Option 05 Video Tri
105. Modes Work 065 3 21 Acquisition Menu and Readout 000 3 23 Acquire Menu Stop After c eee eeeee 3 25 AAMNAS TING s ereere cola vase Gis E o Staines E Wale te ee e Oe 3 27 Display Menu Style ccc cece eee e ce cnes 3 29 Trigger Point and Level Indicators 3 30 Display Menu Setting c ccc ee eee cnes 3 33 Display Menu Palette Colors e0005 3 35 Display Menu Map Reference Colors 3 36 Display Menu Restore Colors 0e0005 3 37 Zoom Mode with Horizontal Lock Set to None 3 39 Dual Window Preview Mode ceccccecee 3 41 Dual Zoom Shown in Dual Window Preview E E E E A O E AER 3 42 Normal DSO Acquisition and Display Mode Versus Insta Vu A RE EOE E E E E A A N 3 44 Insta Vu Display 0 66 6 6 6 9 0i8ce csser e cassee wise sees es 3 45 Fast Frame sec is 0s4 04 bo ied iow oee aED E eats 3 46 Horizontal Menu FastFrame Setup 3 47 Triggered Versus Untriggered Displays 3 49 Trigger Holdoff Time Ensures Valid Triggering 3 52 Slope and Level Controls Help Define the Trigger 3 53 TRIGGER Controls and Status Lights 3 54 Example Trigger Readouts Edge Trigger Selected oorun enne 0 aaa adie Reese aS eres OR Ae 3 56 Figure 3 35 Record View Trigger Position and Trigger Level Bar Read US 55 sii ia dois a recs keene iS bisa BOG
106. Mono Img 3 122 EPS Mono Plt 3 122 Epson 3 122 Format 3 122 GPIB 3 123 HPGL 3 122 Interleaf 3 122 Landscape 3 122 Laserjet 3 122 Index 6 Layout 3 122 OK Confirm Clear Spool 3 126 Palette 3 123 PCX 3 122 PCX Color 3 122 Port 3 123 Portrait 3 122 RLE Color 3 122 Thinkjet 3 122 TIFF 3 122 Hardcopy Color menu 3 34 Hardcopy Utility menu 3 131 Help Accessing 3 133 HELP button 3 135 Help system 3 133 HF Rej Main Trigger menu 3 58 Hi Res Incompatible with InstaVu 3 46 Hi Res acquisition mode 3 22 Glossary 4 Hi Res Acquire menu 3 23 High 3 88 Glossary 5 High Ref Measure menu 3 94 High speed active probes E 3 High voltage probes E 2 High Low Setup Measure menu 3 92 Hi Res acquisition mode 3 48 Histogram Measure menu 3 92 Holdoff trigger 3 51 Glossary 5 Horiz Pos Horizontal menu 3 16 Horiz Scale Horizontal menu 3 15 Horizontal Bar cursors 3 97 Glossary 5 Control 3 13 3 48 Menu 3 53 Position 3 13 Readouts 3 13 Scale 3 13 SCALE knob 2 13 System 2 13 Horizontal Lock Zoom menu 3 39 Horizontal menu 3 83 Delayed Only 3 83 Delayed Runs After Main 3 16 3 83 Delayed Scale 3 15 Delayed Triggerable 3 16 3 83 FastFrame 3 47 FastFrame Setup 3 47 Fit to screen 3 15 Frame Count 3 47 Frame Length 3 47 Frame 3 47 Horiz Pos 3 16 Horiz Scale 3 15 TDS 684A TDS 744A amp
107. NU gt Type main gt Logic pop up gt Class main gt Setup Hold pop up gt Clock Source main gt Ch1 Ch2 Ch3 or Ch4 side 2 Press any one of Ch1 Ch2 Ch3 or Ch4 side Do not select the same channel that you selected for the clock source 3 Press Clock Edge side to toggle between the rising and falling edges Set the Data and Clock Levels To set the transition levels that the clock and data must cross to be recognized by the oscilloscope 1 Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt Setup Hold pop up gt Levels main gt Clock Level or Data Level side 2 Turn the general purpose knob or use the keypad to set values for the clock level and for the data level you select If you prefer you can set both clock levels to a value appropriate to either of two logic families To do so 3 Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt Setup Hold pop up gt Levels main gt Set Both to TTL or Set Both to ECL side The oscilloscope uses the clock level you set to determine when a clock edge rising or falling depending on which you select occurs The oscilloscope uses the point the clock crosses the clock level as the reference point from which it measures setup and hold time settings Set the Setup and Hold Times To set the setup time and the hold time relative to the clock 1 Press TRIGGER MENU gt Type main gt Logic po
108. O af Table of Contents General Safety Summary cece cece ccc ccc csecscees ix Prefac lt 5 sitewide se nhs ewe Mawes Meee S Sore es eae lbs SSR 6 xiii Related Mantal sios ecen aT aaa E a a was bide E S xiii Conventions seeyan E AE Aes Pe E DEA Ra a E eee E xiv Defa lt Model cy Sen i ae e eee ek NE tte te Me Oe RN xiv Getting Started Product Description 0 cece cece cece cece eee e eee eees 1 1 Product Specification sneen ccc eet e een eens 1 2 Start Up serrate ace ces dl aso essen dh share g wee anage Ge E ap oiecevteonas anes 9 E E 1 3 Preparation 3 ic4 enc hics hee eta snes tale e Sache a Wiad Savane Beene 1 3 Putting into Services eis eke eee a itis bea os E av bala le toes Roach eas 1 4 Operating Basics OVERVIEW 608k c CEG ONE E OR REESE EE ee Carew ee Shaw es 2 1 Operating Interface Maps cc cece cece cece cece ee eeee 2 3 Tutorial 26cde ie ace teens Aten ns eet osee nae hase yea wae e s 2 9 Setting Up for the Examples 2 0 0 0 c cece eet eens 2 9 Example 1 Displaying a Waveform 2 00 eee eee ee eee ene 2 13 Example 2 Displaying Multiple Waveforms 0 2 00 ee eee eee 2 15 Example 3 Taking Automated Measurements 0 essence 2 19 Example 4 Saving Setups 000 cee cece erreneren 2 24 Reference OVERVIEW si csaios oe mace iiaee n ee Saws weed aaa E e ae 3 1 Acquiring and Displaying Waveforms eeeeeeeees 3 3 Coupling Wa
109. Postscript 3 121 Posttrigger Glossary 8 Power connector 1 4 2 5 Power cords A 1 Power off 1 6 Power on 1 5 Pretrigger Glossary 8 Preview Zoom menu 3 40 Principal power switch 1 5 2 5 Print File Utilities menu 3 119 Printer Color Option 5 A 2 Printing a Hardcopy Reference Article 3 120 Probe Cal 3 104 3 110 Probe usage 1 3 Probes Accessories A 4 Active voltage E 3 E 6 Compensation 2 15 Glossary 8 Compensation of 3 3 Compensation Signal 2 13 Connection 2 9 Current E 4 Definition Glossary 8 Differential active E 3 TDS 684A TDS 744A amp TDS 784A User Manual Index Fixtured active E 3 General purpose high input resistance E 1 High speed E 3 High voltage E 2 Low impedance Zo E 2 Optical E 5 Option 23 to add A 2 Option 26 to add A 2 P6205 Active 1 3 Passive 3 3 Passive voltage E 1 E 6 Selection E 1 E 6 Time to voltage converter E 5 Product description 1 1 Propagation delay 3 88 Pulse trigger 3 50 3 70 definition of classes 3 70 Pulse triggers definitions of 3 71 Pulse Main Trigger menu 3 57 3 74 3 76 Q Quantizing Glossary 8 R Rack mounting A 2 Readout Acquisition 3 23 Channel 2 6 3 8 3 38 Cursors 2 6 Edge trigger 3 57 General purpose knob 2 6 Logic trigger 3 64 Measurement 3 90 Record view 2 6 Snapshot 3 95 Time base 2 6 Trigger 2 6 3 55 3 56 Trigger Level Bar 3 29 Trigger
110. Repeatedly press the same button until intg appears in the menu label 6 Press OK Create Math Waveform side to turn on the integral math waveform You should now have your integral math waveform on screen See Fig ure 3 97 Use the Vertical SCALE and POSITION knobs to size and position your waveform as you require TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications Tek Run 5 00MS s Sample Math Integral Math Waveform J Change Math waveform definition re ee ees ee eee AAN Source Waveform 41 Average 2 Oooo o ch SMN 3 M 10 0ys chi 320mV DHUA _5 0opvs 10 0us ae Math1 Math2 Matha g a difftch FTRT Ref Ref2 Ref3 DIAC O C O Figure 3 97 Integral Math Waveform To Take Cursor Once you have displayed your integrated math waveform use cursors to measure Measurements its voltage over time 1 Be sure MORE is selected lighted in the channel selection buttons and that the integrated math waveform is selected in the More main menu 2 Press CURSOR Mode main gt Independent side gt Func tion main gt H Bars side 3 Use the general purpose knob to align the selected cursor solid to the top or to any amplitude level you choose 4 Press SELECT to select the other cursor 5 Use the general purpose knob to align the se
111. Res mode the oscilloscope will acquire a waveform record with the first valid trigger event and stop Peak Detect and Hi Res are only available on TDS 700A models In Envelope or Average mode the oscilloscope will make the specified number of acquisitions to complete the averaging or enveloping task TDS 700A models only If the oscilloscope is in equivalent time mode and you press Single Acquisition Sequence side it will continue to recognize trigger events and acquire samples until the waveform record is filled NOTE To quickly select Single Acquisition Sequence without displaying the Acquire and Stop After menus press SHIFT FORCE TRIG Now the RUN STOP button operates as just described You still must display the Acquire menu and then the Stop After menu to leave Single Acquisition Sequence operation Press Limit Test Condition Met side to acquire waveforms until waveform data exceeds the limits specified in the limit test Then acquisition stops At that point you can also specify other actions for the oscilloscope to take using the selections available in the Limit Test Setup main menu NOTE In order for the oscilloscope to stop an acquisition when limit test conditions have been met limit testing must be turned ON using the Limit Test Setup main menu Setting up limit testing requires several more steps See Limit Testing on page 3 137 Under certain conditions a waveform may be aliased on screen Read
112. Select Edge Triggering To Select a Source To Specify Coupling DC ACM 3 58 Use the edge trigger menu to select edge triggering and to perform the proce dures for source coupling slope trigger level mode and holdoff that follow To bring up the Edge Trigger menu press TRIGGER MENU gt Type main gt Edge pop up See Figure 3 37 Tek Run 100kS 5 Hi Res Edge Source Logic lomv O M 500qms Chi 26 8mv more Pulse A i 1of2 yden P See coupling Slope Level ode Type A amp Mr chi BC f 26 3mV ot ioe ems a es es a Oooo o Figure 3 37 Main Trigger Menu Edge Type To select which source you want for the trigger Press TRIGGER MENU gt Type main gt Edge pop up gt Source main gt Ch1 Ch2 Ch3 Ch4 AC Line or DC Aux side To select the coupling you want press TRIGGER MENU gt Type main gt Edge pop up gt Coupling main gt DC AC HF Rej LF Rej or Noise Rej side DC passes all of the input signal In other words it passes both AC and DC components to the trigger circuit AC passes only the alternating components of an input signal It removes the DC component from the trigger signal HF Rej removes the high frequency portion of the triggering signal That allows only the low frequency components to pass on to the trig
113. Snapshot arm Vleasrmnat OFF Histogram Levels OIOI Daoa Figure 3 53 Measure Menu Remove Measurements The Remove Measrmnt selection provides explicit choices for removing measurements from the display according to their readout position To remove measurements do the following steps 1 Press MEASURE Remove Measrmnt main 2 Select the measurement to remove from the side menu If you want to remove all the measurements at one time press All Measurements side Gate Measurements The gating feature lets you limit measurements to a specified portion of the waveform When gating is Off the oscilloscope makes measurements over the entire waveform record When gating is activated vertical cursors are displayed Use these cursors to define the section of the waveform you want the oscilloscope to measure This section is called the gated region Do the following steps to gate a measurement 1 Press MEASURE gt Gating main gt Gate with V Bar Cursors side See Figure 3 54 TDS 684A TDS 744A amp TDS 784A User Manual 3 91 Measuring Waveforms Define High Low Setup 3 92 2 Using the general purpose knob move the selected the active cursor Press SELECT to change which cursor is active Displaying the cursor menu and turning V Bar cursors off will not turn gating off Gating arrows remain on screen to indicate the area over which the measurement is
114. Style Filter Format Trig T Trig Bar Trigger Vectors Sin x x WT ON Short 99 Display Intensity Text wfm Contrast 85 60 75 150 Measure Gate Hi Low Waveforms OFF Histogram 98 58 tO S50 Yo OII CIDIa Format Layout Port tnterleaf Portrait GPIB chi toomv Ch2 1oomV M 500ps Chi OV iE 100mv cCh4 100m ue Ha Figure 3 79 Status Menu System a a Tek Run 5 00GS 5 Sample Tektronix TDS 684A Digitizing Oscilloscope FY 1 08 Options 1F 2F c Copyright Tektronix Inc 1991 1992 1993 1994 All rights reserved U S patents 4 251 754 4 476 432 4 510 571 4 585 975 4 647 862 LOJO O CO Banner ICIP OCI e Figure 3 80 Banner Display 3 134 TDS 684A TDS 744A amp TDS 784A User Manual Determining Status and Accessing Help Displaying Help To use the on line help system Press HELP to provide on screen information on any front panel button knob or menu item See Figure 3 81 Help Mode is on Push HELP to exit Press any button or turn any knob for information about that control Changing a control while in help mode will not affect the digitizing oscilloscope settings Press HELP again to exit the help mode Press the SHIFT button before pressing front panel buttons that bring up he
115. T 2gemv Hoio lt Edge gt Press here to remove menus from Press to display pop up menus screen Press it again to make selection Alternatively press SHIFT first to make selection in the opposite direction A pop up selection changes the other main menu titles TDS 684A TDS 744A amp TDS 784A User Manual 2 8 E A Tutorial This section quickly makes you acquainted with some of the fundamental operations required to use the TDS Oscilloscope to take measurements Start this tutorial by doing Setting Up for the Examples on this page Setting Up for the Examples Perform the following tasks to connect input signals to the TDS Oscilloscope to reset it and to become acquainted with its display screen Once completed these tasks ready the oscilloscope for use in the examples that follow Connect the Input Signal Remove all probes and signal inputs from the input BNC connectors along the lower right of the front panel Then using an appropriate probe such as the P6245 connect from the CH 1 connector of the oscilloscope to the PROBE COMPENSATION connectors See Figure 2 1 oo0oo0oo0oo0oo f N l em E aa S ao E n oO LOY WS o o Oil See om 000 0 DOO SlSoo Ole al o000 lc Z oO O00 r SY SaSao
116. The German Postal Service requires that systems assembled by the operator user of this instrument must also comply with Postal Regulation Vfg 243 1991 Par 2 Sect 1 HINWEIS fiir den Benutzer Betreiber Die vom Betreiber zusammengestellte Anlage innerhalb derer dieses Ger t eingesetzt wird mu ebenfalls den Voraussetzungen nach Par 2 Ziff 1 der Vfg 243 1991 gen gen NOTICE to the user operator The German Postal Service requires that this equipment when used in a test setup may only be operated if the requirements of Postal Regulation Vfg 243 1991 Par 2 Sect 1 8 1 are complied with HINWEIS fiir den Benutzer Betreiber Dieses Ger t darf in Mefaufbauten nur betrieben werden wenn die Voraussetzungen des Par 2 Ziff 1 8 1 der Vfg 243 1991 eingehalten werden Tektronix EC Declaration of Conformity Tektronix Holland N V Marktweg 73A 8444 AB Heerenveen The Netherlands declare under sole responsibility that the TDS 684A TDS 744A and TDS 784A Digitizing Oscilloscopes meet the intent of Directive 89 336 EEC for Electromagnetic Compatibility Compliance was demonstrated to the following specifications as listed in the official Journal of the European Communities EN 50081 1 Emissions EN 55022 Radiated Class B EN 55022 Radiated Class B EN 60555 2 Power Harmonics EN 50082 1 Immunity IEC 801 2 Electrostatic Discharge IEC 801 3 RF Radiated IEC 801 4 Fast Transients IEC 801 5 Surge
117. The number of hardco pies that can be spooled depends on three variables m The amount of unused RAM m The hardcopy format chosen m The complexity of the display Although not guaranteed usually about 2 5 hardcopies can be spooled before the oscilloscope must wait to send the rest of the third copy To send hardcopies to a floppy disk do the following steps 1 Set up the oscilloscope communication and hardware parameters as outlined in To Set Up for Making Hardcopies on page 3 122 2 Insert a formatted 720 Kbyte or 1 44 Mbyte floppy disk into the slot at the left of the oscilloscope display NOTE To format disks delete hardcopy files you save to disk and otherwise manage the disk storage see Managing the File System on page 3 117 3 Press SHIFT gt HARDCOPY MENU gt Port main gt File side to specify that any hardcopy made be output to a file on the floppy drive The file list and its scrollbar will appear 4 Turn the general purpose knob to place the scroll bar over the file in which to store the hardcopy NOTE Upon power on the oscilloscope creates the wild card file hardcopy format you select Selecting this file and pressing Hardcopy stores a hardcopy in a uniquely named sequentially numbered file For instance the oscilloscope saves the first hardcopy you save to the file TEKO0001 FMT the second to TEK00002 FMT and so on 5 Press HARDCOPY to print your hardcopy to the selected file
118. This section describes how to use the following features to save recall and document your measurements m Save Recall Setups for saving the setups you create to internal memory or to a floppy disk so you can recall and reuse those setups m Save Recall Waveform for saving waveforms to internal memory or to a floppy disk and for recalling those waveforms to the display m Hardcopy for printing a copy of the oscilloscope display screen or for saving it to floppy disk hardcopies can be incorporated into documents using desk top publishing software m File Utilities for managing copying organizing into directories and so on the setups waveforms and display screens that you save to floppy disk This section ends with details on how to connect your oscilloscope into a system environment so that it can communicate with remote instruments Saving and Recalling Setups To Save a Setup The TDS Oscilloscope can store up to ten instrument setups in internal memory that you may later recall This subsection describes how you save and recall a setup and how you can recall the factory default setup Save a setup when you want to reuse it later For example after changing the setting during the course of an experiment you may want to quickly return to your original setup Save setups are retained even when you turn the oscilloscope off or unplug it To save the current setup of the oscilloscope 1 Press SAVE RECALL SETUP Save Cur
119. UT Provides Main Trigger TTL Output DELAYED TRIGGER OUTPUT Provides Delayed Trigger TTL Output TDS 684A TDS 744A amp TDS 784A User Manual 2 5 Operating Interface Maps Display Map The Indicates position of When present the general acquisition vertical bar cursors in the Trigger The value entered with purpose knob makes coarse status waveform record position T the general purpose adjustments when absent page 3 23 page 3 100 page 3 56 knob or keypad fine adjustments A Tek Run 5 00GS 5 Samply Trigger Level 252mV X Shows what part of the waveform The waveform record is displayed page 3 13 record icon a j k Tek Run 5 00GS 5 Sample _Trigger Level 252mV G waveform may be an evel Cursor measurements arrow at right side of page 3 97 screen instead of a bar ea J 252m Set to TTL The side menu with choices of specific actions Channel level and waveform source set to ECL Vertical scale page 3 10 Trigger parameters page 3 55 raw BO BER ea Type Sai amp eEige gt ch oC T ERTE dof The main menu with Horizontal scale and time choices of major actions base type page 3 13 2 6 TDS 684A TDS 744A amp TDS 784A User Manual Operating Interface Maps To Operate a Menu 1 Press front panel menu button Press SHIFT first if button label is blu
120. User Manual Tektronix TDS 684A TDS 744A amp TDS 784A Digitizing Oscilloscopes 070 8991 02 This document applies for firmware version 1 0 and above Copyright Tektronix Inc 1994 All rights reserved Licensed software products are owned by Tektronix or its suppliers and are protected by United States copyright laws and international treaty provisions Use duplication or disclosure by the 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 or subparagraphs c 1 and 2 of the Commercial Computer Software Restricted Rights clause at FAR 52 227 19 as applicable Tektronix products are covered by U S and foreign patents issued and pending Information in this publication supercedes that in all previously published material Specifications and price change privileges reserved Printed in the U S A Tektronix Inc P O Box 1000 Wilsonville OR 97070 1000 TEKTRONIX TEK FastFrame FlexFormat and InstaVu are registered trademarks of Tektronix Inc WARRANTY Tektronix warrants that this product will be free from defects in materials and workmanship for a period of three 3 years from the date of shipment If any such product proves defective during this warranty period Tektronix at its option either will repair the defective product without charge for parts and labor or will provide a replacement i
121. Verification and Specifications that is shipped as a standard accessory with the TDS Oscilloscope TDS 684A TDS 744A amp TDS 784A User Manual Start Up Preparation Signal Path Compensation Recommended Probes Probe Usage A Input Coupling Before you use the TDS Oscilloscope ensure that it is properly installed and powered on To ensure maximum accuracy for your most critical measurements you should know about signal path compensation and the proper use of the probe you choose to use with your oscilloscope Be sure you compensate your oscilloscope for the surrounding temperature This action called Signal Path Compensation SPC ensures maximum possible accuracy for your most critical measurements See Signal Path Compensation on page 3 102 for a description of and operating information on this feature The TDS 744A Oscilloscope ships with four general purpose P6139A 500 MHz passive probes The TDS 684A and TDS 784A Oscilloscopes ship without probes To take advantage of the higher bandwidth of the TDS 684A and TDS 784A Oscilloscopes order the P6245 Active Probe See Appendix A Options and Accessories in this manual for more information on optional acces sory probes for all three oscilloscope models Be sure you use the appropriate probe for the measurement For instance do not use the P6245 Active Probe to measure signals greater than 8 volts or with more than 10 volts of offset since errors in signal measure
122. a Tek Run 100kKS 5 Sample Oooo o gil oom sons CHT A 252mv DIG ICCC Figure 2 9 The Display After Pressing Autoset NOTE If you are using a passive probe such as the P6139A probe the corners on your displayed signal may look rounded or pointed See Figure 2 10 If so then you may need to compensate your probe See To Compensate Passive Probes on page 3 3 JE ek Figure 2 10 Display Signals Requiring Probe Compensation Example 2 Displaying Multiple Waveforms The TDS Oscilloscope can display up to four channels three math waveforms and four reference waveforms at one time Do the following tasks to learn how to display and control more than one waveform at a time TDS 684A TDS 744A amp TDS 784A User Manual 2 15 Tutorial Add a Waveform The VERTICAL section of the front panel contains the channel selection buttons These buttons are CH 1 CH 2 CH 3 CH 4 and MORE See Fig ure 2 11 MATH REF a A VERTICAL CH1 a O C CH2 ven ZOOM C D CH3 A SCALE zZ J CH 4 J MORE M WAVEFORM OFF J Figure 2 11 The Channel Buttons and Lights Each of the channel CH buttons has a light behind its label Right now the CH 1 light is on That light indicates that the vertical controls are set to adjust channel 1 Do the following steps to add a wavefor
123. acquisition mode A mode that increases the waveform capture rate to up to 400 000 wave forms per second This very fast capture rate greatly increases the probability that runts glitches and other short term changes will accumulate in waveform memory The oscilloscope then displays the waveform at the normal display rate using variable or infinite persistence Interleaving TDS 700A Models Only A method by which the TDS 744A and TDS 784A Oscilloscopes attain higher digitizing speeds The oscilloscope applies the digitizing resources of unused channels that is channels that are turned off to sample those that are in use turned on Table 3 2 on page 3 19 lists acquisition rates vs number of channels that are on TDS 684A TDS 744A amp TDS 784A User Manual Glossary 5 Glossary S Glossary 6 Knob A rotary control Logic state trigger The oscilloscope checks for defined combinatorial logic conditions on channels 1 2 and 3 on a transition of channel 4 that meets the set slope and threshold conditions If the conditions of channels 1 2 and 3 are met then the oscilloscope triggers Logic pattern trigger The oscilloscope triggers depending on the combinatorial logic condition of channels 1 2 3 and 4 Allowable conditions are AND OR NAND and NOR Low The value used as 0 in automated measurements whenever high ref mid ref and low ref values are needed as in fall time and rise tim
124. ady displayed To explore assigning controls to different channels do the following steps 1 Press CH 1 Observe that now the side menu title shows Ch1 See Figure 2 13 and that the light above CH 1 is lighted The highlighted menu item in the side menu has changed from the 50 Q channel 2 setting to the 1 MQ impedance setting of channel 1 2 Press CH 2 gt Q side to toggle the selection to 1 MQ That returns the coupling impedance of channel 2 to its initial state Tek Run 100kKS 5 Sample 200mv ch2 100mVQ M 500ys chi 7 252mv Offset ov BRE Bandwidth Fine Scale position Cal Probe Full ett a div initialized eb Coupling Side Menu Title mpedance HEA 50 ITI G Co an as Figure 2 13 The Menus After Changing Channels Remove a Waveform Pressing the WAVEFORM OFF button removes the waveform for the currently selected channel If the waveform you want to remove is not already selected select that channel using the channel CH button 1 Press WAVEFORM OFF under the vertical SCALE knob TDS 684A TDS 744A amp TDS 784A User Manual Tutorial 2 Since the CH 2 light was on when you pressed the WAVEFORM OFF button the channel 2 waveform was removed The channel CH lights now indicate channel 1 Channel 1 has become the selected channel When you remove the last wav
125. agation delay 3 88 Readout 3 90 Reference levels 2 21 Rise time 2 20 3 89 Glossary 9 RMS 3 89 Glossary 9 Undershoot Glossary 7 Width 2 20 Glossary 7 Glossary 8 Measurement Accuracy Ensuring maximum 3 102 3 104 3 110 Measurements 3 87 3 110 Algorithms B 1 B 14 Automated 2 19 3 87 3 110 Classes of 3 87 3 110 Cursor 3 87 3 110 Gated 3 91 Graticule 3 87 3 110 Snapshot of 3 95 Measuring Waveforms 3 87 Memory Waveform 3 115 Menu Acquire 3 23 3 138 Color 3 33 Cursor 3 99 Delayed Trigger 3 83 3 86 Display 3 28 3 33 File Utilities 3 117 Horizontal 3 53 3 83 Main 2 6 Main Trigger 3 57 3 58 3 64 3 67 3 68 3 72 3 74 3 77 Measure 3 90 3 95 More 3 115 3 142 3 146 3 162 See also More menu Operation 2 7 Pop up 2 8 Glossary 8 TDS 684A TDS 744A amp TDS 784A User Manual Save Recall 3 111 Save Recall Waveform 3 114 Setup 2 10 3 7 Status 3 133 3 136 Utility 3 122 Measurements List of automated 3 88 Mid Ref Measure menu 3 94 Mid2 Ref Measure menu 3 94 Min Max Measure menu 3 92 Minimum 3 89 Glossary 6 Mode amp Holdoff Main Trigger menu 3 59 Model number location 2 3 Monochrome Color menu 3 34 MORE button 3 8 3 115 3 139 3 142 More menu 3 115 3 142 3 162 Average 3 144 Blackman Harris 3 148 Change Math waveform definition 3 146 3 162 3 166 dBV RMS 3 147 diff 3 162 Dual Wfm
126. age Measured over the entire waveform or gated region A Mean Voltage measurement The arithmetic mean over the entire waveform or gated region rf Minimum Voltage measurement The minimum amplitude Typically the most negative peak voltage u Measured over the entire waveform or gated region Negative Duty Cycle Timing measurement of the first cycle in the waveform or gated region The ratio of the negative pulse width to the signal period expressed as a percentage Negative Width OK NegativeDutyCycle Period 100 Negative Overshoot Voltage measurement Measured over the entire waveform or gated region _ Low Min 7 NegativeOvershoot Amplitude x 100 Negative Width Timing measurement of the first pulse in the waveform or gated region The distance time between MidR ef default 50 amplitude points of a negative pulse P Peak to Peak Voltage measurement The absolute difference between the maximum and minimum amplitude Bo in the entire waveform or gated region GAT Phase Timing measurement The amount one waveform leads or lags another in time Expressed in degrees where 360 comprise one waveform cycle Period Timing measurement Time it takes for the first complete signal cycle to happen in the waveform or gated region The reciprocal of frequency Measured in seconds Positive Duty Cycle Timing measurement of the first cycle in the waveform or gated region The ratio of the positive pulse width to the signal period expressed
127. age 3 151 To measure the phase relative to most source waveforms you need only to center the positive peak around the zero phase point For instance center the positive half cycle for a sine or square wave around the zero phase point Use the following method m First be sure the FFT math waveform is selected in the More menu then set horizontal position to 50 in the Horizontal menu This positions the zero phase reference point to the horizontal center of the screen m In the Horizontal menu vary the trigger position to center the positive peak of the source waveform at the horizontal center of screen Alternately you can adjust the trigger level knob to bring the positive peak to center screen if the phase reference waveform has slow enough edges When impulse testing and measuring phase align the impulse input into the system to the zero reference point of the FFT time domain waveform m Set the trigger position to 50 and horizontal position to 50 for all record lengths less than 15 K TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications m For records with a 100 K length TDS 700A models with Option 1M only set the trigger position to 5 Use the horizontal position knob to move the trigger T on screen to the center horizontal graticule line m Do not use the 15 K all models 30 K TDS 700A models 75 K or 130 K TDS 700A models equipped with Option 1M to impulse test using
128. anging the acquisition parameters sample rate record length and so on This subsection describes how to use Zoom and how it interacts with the selected waveform It also describes how interpolation can affect Zoom Use Zoom press the ZOOM button when you want to temporarily expand a waveform to inspect small feature s on that waveform For example to temporarily expand the front corner of a pulse to inspect its aberrations use Zoom to expand it horizontally and vertically After you are finished you can return to your original horizontal scale setting by pressing one menu button Zoom is also handy if you have acquired a waveform at the fastest time per division and want to further expand the waveform horizontally To help you use zoom effectively consider how it operates on waveforms When zooming vertically the oscilloscope expands or contracts the selected waveform only Also the oscilloscope only positions the selected waveform when in Zoom When zooming horizontally Zoom expands either the selected waveform all live waveforms or all live and reference waveforms depending on the setting for Horizontal Lock in the Zoom menu TDS 684A TDS 744A amp TDS 784A User Manual 3 37 Acquiring and Displaying Waveforms Interpolation and Zoom Checking the Zoom Factor 3 38 Zoom a Waveform When zooming horizontally or vertically Zoom expands or contracts the waveform by the zoom factor in 1X 2X and 5X steps To hel
129. as a percentage Pa _ PositiveWidth PositiveDutyCycle Period x 100 Positive Overshoot Voltage measurement over the entire waveform or gated region PositiveOvershoot V HOA X 100 Amplitude Positive Width Timing measurement of the first pulse in the waveform or gated region The distance time between MidR ef default 50 amplitude points of a positive pulse Le Rise time Timing measurement Time taken for the leading edge of the first pulse in the waveform or gated region to rise from a Low Ref value default 10 to a High Ref value default 90 of its final value rp RMS Voltage measurement The true Root Mean Square voltage over the entire waveform or gated region TDS 684A TDS 744A amp TDS 784A User Manual 3 89 Measuring Waveforms Measurement Readouts Measurement Readout Area With no menus displayed the measurement readouts appear far right of the display graticule See Figure 3 52 You can display and continuously update as many as four measurements at any one time With any menu displayed the readouts move to the right side of the graticule area Tek Run 100kS 5 Sample chi Period 1 000ms chi width E 500s Display Measurements 3 90 chi Over 6 5 Loloooo a om a 0ps Chi F 208m CICIClO IC IOC Figure 3 52 Measurement Readouts Measurement 1 is the top readout Measur
130. asurements of 3 150 DC correction 3 153 derivation of 3 145 displaying phase 3 147 frequency range 3 152 frequency resolution 3 152 interpolation mode 3 154 magnifying 3 154 phase display setup considerations 3 156 TDS 684A TDS 744A amp TDS 784A User Manual phase suppression 3 148 3 157 procedure for displaying 3 146 procedure for measuring 3 149 record length 3 152 reducing noise 3 154 undersampling 3 155 zero phase reference 3 156 FFT time domain record defined 3 151 File System 3 117 3 132 File Utilities menu 3 117 Confirm Delete 3 120 Copy 3 119 Create Directory 3 119 Delete 3 118 File Utilities 3 117 Format 3 120 Overwrite Lock 3 120 Print 3 119 Rename 3 118 File Utilities File Utilities menu 3 117 File Utilities Save Recall Setup menu 3 113 File Utilities Save Recall Waveform menu 3 117 Filter Display menu 3 31 Fine Scale Vertical menu 3 12 Firmware version 3 133 Fit to screen Horizontal menu 3 15 Fixtured active probes E 3 FORCE TRIG button 3 54 Format File Utilities menu 3 120 Format Hardcopy menu 3 122 Frame Count Horizontal menu 3 47 Frame Length Horizontal menu 3 47 Frame Display menu 3 31 Frame Horizontal menu 3 47 Frequency 2 19 3 88 Glossary 4 Front Cover removal 1 5 Front panel 2 4 Full Display menu 3 31 Full Vertical menu 3 12 Function Cursor menu 3 99 3 100 Fuse 1 4 2 5 G Gated Measur
131. ate Measurement Measure Delay menu 3 95 OK Erase Ref amp Panel Memory Utility menu 3 113 OK Store Template Acquire menu 3 139 ON Enable ET Acquire menu 3 24 ON STBY button 1 5 2 3 Optical probes E 5 Options A 1 A 6 Options Color menu 3 36 OR Glossary 7 OR Main Trigger menu 3 66 3 68 Oscilloscope Glossary 7 Overall Display menu 3 29 Overshoot Glossary 8 Overwrite Lock File Utilities menu 3 120 P P6205 Active Probe 1 3 Packaging C 1 Paired cursor 3 97 PAL Display menu 3 31 Palette Color menu 3 33 Palette Hardcopy menu 3 123 Passive voltage probes E 1 E 6 Index 10 Pattern trigger 3 61 How to setup 3 64 3 86 PCX 3 121 PCX Color Hardcopy menu 3 122 PCX Hardcopy menu 3 122 Peak detect acquisition mode 3 22 Glossary 7 Peak Detect Acquire menu 3 23 Peak to peak 3 89 Glossary 7 Period 3 89 Glossary 7 Persistence 3 28 Persistence Palette Color menu 3 34 Phase 3 89 Glossary 7 Phase suppression 3 157 Pixel Glossary 8 Polarity and Width Main Trigger menu 3 73 Polarity Main Trigger menu 3 74 3 77 Pop up menu 2 8 Glossary 8 Port Hardcopy menu 3 123 Port Utility menu 3 131 Portrait Hardcopy menu 3 122 Position Vertical 3 11 vertical 3 153 3 164 3 169 Position Vertical menu 3 12 Positive duty cycle 3 89 Positive overshoot 3 89 Positive width 3 89 Positive Main Trigger menu 3 73 3 74 3 77
132. ate a wave form record containing a user specified number of data or record points Each record point represents a certain voltage level that occurs a determined amount of time from the trigger event The oscilloscope may take more samples than the number of points in your waveform record In fact the oscilloscope may take several samples for each record point see Figure 3 10 The digitizer can use any extra samples to perform additional processing such as averaging or looking for minimum and maximum values The methods of sampling and acquisition modes you choose determine how the oscilloscope assembles the sample points it acquires into the waveform record lt Interval for one waveform record point Samples for a record point Figure 3 10 Several Points May be Acquired for Each Point Used Real time Sampling The two general methods of sampling are real time and equivalent time The TDS 684A Oscilloscope uses only real time sampling the TDS 700A Oscillo scopes use both real and equivalent time sampling In real time sampling the oscilloscope digitizes all the points it acquires after one trigger event see Figure 3 11 Always use real time sampling to capture single shot or transient events Record Points 1e a T Sampling Rate JUUUUUUUUUL Figure 3 11 Real Time Sampling TDS 684A TDS 744A amp TDS 784A User Manual 3 17 Acquiring and Displaying Waveforms Equivalent Time Sampling 3 18 Interpolation
133. ath1 to 3 140 Compare Math2 to 3 140 Compare Math3 to 3 140 Create Limit Test Template 3 138 Envelope 3 23 H Limit 3 139 Hardcopy if Condition Met 3 140 Hi Res 3 23 Limit Test 3 141 Limit Test Condition Met 3 141 Limit Test Setup 3 140 3 141 Limit Test Sources 3 140 Limit Testing 3 138 OFF Real Time Only 3 24 OK Store Template 3 139 ON Enable ET 3 24 Peak Detect 3 23 Repetitive Signal 3 24 Ring Bell if Condition Met 3 140 RUN STOP 3 26 Sample 3 23 Single Acquisition Sequence 3 26 Stop After 3 25 3 141 Stop After Limit Test Condition Met 3 140 TDS 684A TDS 744A amp TDS 784A User Manual Template Source 3 138 V Limit 3 139 ACQUIRE MENU button 3 23 3 138 Acquiring and Displaying Waveforms 3 3 Acquisition 3 16 3 48 Glossary 1 Interval Glossary 1 Mode envelope 3 20 Modes Average 3 20 3 48 Envelope 3 48 Hi Res 3 22 3 48 Peak detect 3 22 Sample 3 20 Readout 3 23 Acquisition mode Choosing an 3 16 Acquisition modes How to select 3 23 Incompatible with InstaVu 3 46 Active cursor Glossary 1 Active voltage probes E 3 E 6 active Saved waveform status 3 114 Advanced applications Features for 3 137 Algorithms B 1 B 14 Aliasing 3 26 3 155 Glossary 1 Amplitude 3 88 Glossary 1 Amplitude Units Cursor menu 3 101 AND Glossary 1 AND Main Trigger menu 3 66 3 68 Applications derivative math waveforms 3 162 FFT math wavefo
134. atic measurements in three categories amplitude typically in volts sometimes in time typically in seconds or hertz and area in volt seconds Table 3 9 lists brief definitions of the automated measurements in the oscilloscope for more details see Appen dix B Algorithms page B 1 Table 3 9 Measurement Definitions Name tt Amplitude Area Cycle Area fl Burst Width a Cycle Mean yy Cycle RMS Delay whee Fall Time Definition Voltage measurement The high value less the low value measured over the entire waveform or gated region Amplitude High Low Voltage over time measurement The area over the entire waveform or gated region in volt seconds Area measured above ground is positive area below ground is negative Voltage over time measurement The area over the first cycle in the waveform or the first cycle in the gated region in volt seconds Area measured above ground is positive area below ground is negative Timing measurement The duration of a burst Measured over the entire waveform or gated region Voltage measurement The arithmetic mean over the first cycle in the waveform or the first cycle in the gated region Voltage measurement The true Root Mean Square voltage over the first cycle in the waveform or the first cycle in the gated region Timing measurement The time between the MidR ef crossings of two different traces or the gated region of the traces Timing measure
135. ating point number with values between 0 0 and RecordLength 1 0 inclusive EndCycle MCross3 MCrossl StartCycle MCross3 MCross2 EndCycle Figure B 1 MCross Calculations Waveform lt 0 0 RecordLength 1 0 gt holds the acquired data TPOS is the location of the sample just before the trigger point the time reference zero sample In other terms it contains the domain reference location This location is where time 0 TSOFF is the offset between TPOS and the actual trigger point In other words it is the trigger sample offset Values range between 0 0 and 1 0 samples This value is determined by the instrument when it receives a trigger The actual zero reference trigger location in the measurement record is at TPOS TSOFF TDS 684A TDS 744A amp TDS 784A User Manual Appendix B Algorithms Measurement Algorithms Amplitude Area Cycle Area Burst Width UU The automated measurements are defined and calculated as follows Amplitude High Low The arithmetic area for one waveform Remember that one waveform is not necessarily equal to one cycle For cyclical data you may prefer to use the cycle area rather than the arithmetic area if Start End then return the interpolated value at Start Otherwise Area p Waveform t dt Start For details of the integration algorithm see page B 12 Amplitude voltage measuremen
136. bar cursors The two vertical bars you position to measure the time parameter of a waveform record The oscilloscope displays the value of the active move able cursor with respect to the trigger and the time value between the bars Waveform The shape or form visible representation of a signal TDS 684A TDS 744A amp TDS 784A User Manual Glossary Waveform interval The time interval between record points as displayed O XY format A display format that compares the voltage level of two waveform records point by point It is useful for studying phase relationships between two waveforms Ead YT format The conventional oscilloscope display format It shows the voltage of a waveform record on the vertical axis as it varies over time on the horizontal axis TDS 684A TDS 744A amp TDS 784A User Manual Glossary 11 Glossary Glossary 12 TDS 684A TDS 744A amp TDS 784A User Manual Index Numbers 1 seconds Hz Cursor menu 3 101 20 MHz Vertical menu 3 12 250 MHz Vertical menu 3 12 A AC coupling Glossary 1 AC line voltage trigger input 3 50 AC Main Trigger menu 3 58 Accept Glitch Main Trigger menu 3 73 Accessories A 1 A 6 Optional A 4 A 6 Probes A 4 Software A 5 Standard A 3 A 5 Accuracy Glossary 1 Acquire menu 3 23 Average 3 23 Average mode 3 138 Compare Ch1 to 3 140 Compare Ch2 to 3 140 Compare Ch3 to 3 140 Compare Ch4 to 3 140 Compare M
137. cating Cursors Outside the Display Cursor Function i l p 10 0m M 200ps Chif 25 6mV p Function ime mpTitude Paired Units seconds OIOI o Figure 3 61 Paired Cursor Menu and Readouts To select the cursor mode and adjust the cursors in either mode do the following steps 1 Press CURSOR Mode main Independent or Track side Independent makes each cursor positionable without regard to the position of the other cursor Track makes both cursors positionable in tandem that is both cursors move in unison and maintain a fixed horizontal or vertical distance between each other 2 Adjust the cursors according to the mode you have selected m To adjust either cursor in independent mode use the general purpose knob to move the selected active cursor A solid line indicates the adjustable cursor and a dashed line the fixed cursor Press Select to toggle selection between the two cursors m To adjust both cursors in tracking mode use the general purpose knob to move both cursors To adjust the distance between cursors in tracking mode press SELECT to temporarily suspend cursor tracking Then use the general purpose knob to TDS 684A TDS 744A amp TDS 784A User Manual Measuring Waveforms adjust the distance of the solid cursor relative to the dashed cursor Press SELECT again to resume tracking Select Cursor S
138. ce by pressing the RUN STOP button to stop the acquisition TDS 684A TDS 744A amp TDS 784A User Manual a fe Sa Triggering on Waveforms Triggering Concepts To use the TDS Oscilloscope to measure or monitor waveforms you need to know how to trigger a stable display of those waveforms Toward that end this section first covers the following topics m Trigger Concepts which details some basic principles of triggering and describes triggering elements type source coupling holdoff mode and so on m Triggering from the Front Panel which describes how to use the front panel triggering controls each of which is common to most if not all the trigger types the oscilloscope provides Once these basics are covered this section describes how to trigger using the various trigger types provided by the Main trigger system edge logic and pulse m To use the general purpose trigger type edge see Triggering on a Waveform Edge on page 3 57 m To logic trigger based on an input pattern state or setup hold violation see Triggering Based on Logic on page 3 60 m To pulse trigger based on various pulse types glitch runt or their parame ters width slew rate see Triggering on Pulses on page 3 70 This section concludes with details about and instructions for using the Delayed time base and Delayed trigger system to delay the acquisition of a waveform relative to a trigger event See Delayed Triggering on page 3 80 T
139. cessing side Any math operations you select for the waveform are performed on only one acquisition The Advanced DSP Math capabilities of the TDS Oscilloscope include taking the Fast Fourier Transform FFT of a waveform This section describes FFTs and how to set up the oscilloscope to display and measure FFTs The FFT allows you to transform a waveform from a display of its amplitude against time to one that plots the amplitudes of the various discrete frequencies the waveform contains Further you can also display the phase shifts of those frequencies Use FFT math waveforms in the following applications 3 144 Testing impulse response of filters and systems Measuring harmonic content and distortion in systems Characterizing the frequency content of DC power supplies Analyzing vibration Analyzing harmonics in 50 and 60 cycle lines Identifying noise sources in digital logic circuits TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications The FFT computes and displays the frequency content of a waveform you acquire as an FFT math waveform This frequency domain waveform is based on the following equation N pie _ j2ank 1 N X k x n e for k 0 toN 1 je 2 Where x n is a point in the time domain record data array X k is a point in the frequency domain record data array n is the index to the time domain data array k is the index to the frequency domain data array N is the
140. ch is on see Figure 1 1 The principal power switch controls all AC power to the instrument 2 If the oscilloscope is not powered on the screen is blank push the front panel ON STBY button to toggle it on see Figure 1 2 Tektronix TDS 684A Sanane oseLioscore WA Tek Run 5 00GS5 5 Sample E Tektronix 7 TDS 6844 Digitizing Oscilloscope FV v1 0e Options 1F 2F c Copyright Tektronix Inc 1991 1992 1993 1994 All rights reserved U S patents 4 231 754 4 476 432 4 510 571 4 585 975 4 647 862 Power On self check PASSED Push CLEAR MENU to proceed TOOMV M10 0ns Chi F OV 25 Mar 1994 12 07 34 ON STBY Button Figure 1 2 ON STBY Button TDS 684A TDS 744A amp TDS 784A User Manual 1 5 Start Up 16 Self Test Power Off The ON STBY button controls power to most of the instrument circuits Power continues to go to certain parts even when this switch is set to STBY Once the oscilloscope is installed it is typical to leave the principal power switch on and use the ON STBY button instead of the power switch The oscilloscope automatically performs power up tests each time it is turned on It will come up with a display screen that states whether or not it passed the self test To determine the self test results check the screen If the self test passed the status display
141. colors by selecting the main menu Map Math item 2 Select one of the three math waveforms by pressing Math in the side menu 3 If you want to assign the selected math waveform to a specific color press Color and cycle through the choices 4 If you want the selected math waveform to be the same color as the waveform it is based on select Color Matches Contents If the math waveform is based on dual waveforms the math waveform will use the color of the first constituent waveform To return to the factory defaults select Reset to Factory Color Set Reference Waveform To define reference waveform colors Color 1 Press Map Reference in the main menu See Figure 3 21 TDS 684A TDS 744A amp TDS 784A User Manual 3 35 Acquiring and Displaying Waveforms 3 36 Select Options Restore Colors 2 Select one of the four reference waveforms by pressing Ref in the side menu 3 To assign the selected reference waveform to a specific color press repeatedly Color and choose the value 4 To make the selected reference waveform the same color as the waveform it is based on select Color Matches Contents To return to the factory defaults select Reset to Factory Color a Tek Run 2 50kS 5 Sample Ref Mappings Ref Refi Settings lt Color gt Palette Normal chi Ch2 Ch3 Ch4 Math Change Colors ap Math Colors ap Reference Colors Options
142. cted cursor relative to ground See Figure 3 61 TDS 700A Models Only In FastFrame mode the A shows the time difference between the two cursors only if both cursors are in the same frame ra Tek Run 100kS s E A 53 2MYN Cursor Cursor Readout H Bars i 1 2mMV Function Non selected Cursor Dashed Line Selected Cursor Solid Line Paired 20 omv C M 500us Chif 25 6mv a i rine Tanpri EENE EREE Function eee Units Units ki seconds Base Gs olololloo Figure 3 60 H Bars Cursor Menu and Readouts Paired cursors can only show voltage differences when they remain on screen If the paired cursors are moved off screen horizontally the word Edge will replace the voltage values in the cursor readout Selectthe This procedure and those that follow detail the process for taking a cursor Cursor Function measurement To select the type of cursors you want do the following steps 1 To display the cursor menu press CURSOR See Figure 3 60 2 Press Function main gt H Bars V Bars Paired or Off side TDS 684A TDS 744A amp TDS 784A User Manual 3 99 Measuring Waveforms 3 100 Cursor Readout Paired Non selected Cursor Dashed Vertical Bar Selected Cursor Solid Vertical Bar Set Mode and Adjust the Cursors Position of Vertical Bar Cursors Useful for Lo
143. ction describes how to manage delete rename etc these files using the file system Read the subsections listed under To Find More Information on page 3 120 for information on saving hardcopies setups and waveforms To Access the File Utilities The File Utilities menu lets you delete rename copy print files create a new directory operate the confirm delete and overwrite lock and format disks To bring up the File Utilities menu 1 Press the SAVE RECALL SETUP button to bring up the Save Recall Setup menu or press the SAVE RECALL WAVEFORM button to bring up the Save Recall Waveform menu or press the SHIFT HARDCOPY button to bring up the Hardcopy menu 2 Press File Utilities in the main menu to bring up the File Utilities side menu See Figure 3 68 TDS 684A TDS 744A amp TDS 784A User Manual 3 117 Saving Waveforms and Setups NOTE The amount of free space on the disk is shown in the upper right corner of the display The oscilloscope shows the amount in Kbytes or in Mbytes if the free space is 1 Mbyte or more To convert the amount to bytes you simply multiply the Kbytes amount times 1024 Thus the 690 Kbytes shown in Figure 3 68 690 Kbytes x 1024 bytes Kbyte 706 560 bytes To Delete To delete a file or directory turn the general purpose knob until it scrolls the cursor over the name of the file or directory to delete Then press the side menu Delete button To delete all files in the file list
144. d before the trigger event Probe An oscilloscope input device Quantizing The process of converting an analog input that has been sampled such as a voltage to a digital value Probe compensation Adjustment that improves low frequency response of a probe Pulse trigger A trigger mode in which triggering occurs if the oscilloscope finds a pulse of the specified polarity with a width between or optionally outside the user specified lower and upper time limits Real time sampling A sampling mode where the oscilloscope samples fast enough to completely TDS 684A TDS 744A amp TDS 784A User Manual Glossary fill a waveform record from a single trigger event Use real time sampling to capture single shot or transient events Record length The specified number of samples in a waveform Reference memory Memory in a oscilloscope used to store waveforms or settings You can use that waveform data later for processing The oscilloscope saves the data even when the oscilloscope is turned off or unplugged Rise time The time it takes for a leading edge of a pulse to rise from a LowRef value typically 10 to a HighRef value typically 90 of its amplitude RMS Amplitude voltage measurement of the true Root Mean Square voltage Runt trigger A mode in which the oscilloscope triggers on a runt A runt is a pulse that crosses one threshold but fails to cross a second threshold before recrossing the first The crossings d
145. d slew rate Pulse triggering is available on the main trigger only Logic is a special purpose trigger primarily used on digital logic circuits Two of the classes pattern and state trigger based on the Boolean operator you select for the trigger sources Triggering occurs when the Boolean conditions are satisfied A third class setup hold triggers when data in one trigger source changes state within the setup and hold times that you specify relative to a clock TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms in another trigger source Logic triggers are available on the main trigger system only Video available as option 05 is a special trigger used on video circuits It helps pel you investigate events that occur when a video signal generates a horizontal or vertical sync pulse Supported classes of video triggers include NTSC PAL SECAM and high definition TV signals Trigger Modes The trigger mode determines how the oscilloscope behaves in the absence of a trigger event The oscilloscope provides two trigger modes normal and automatic Normal trigger mode enables the oscilloscope to acquire a waveform only when it is triggered If no trigger occurs the oscilloscope will not acquire a waveform You can push FORCE TRIGGER to force the oscilloscope to make a single acquisition Automatic trigger mode auto mode enables the oscilloscope to acquire a waveform even if a trigger does not occur Auto
146. d value is used Vertical Scale As determined by the signal level Vertical Coupling DC unless AC was previously set AC remains unchanged Vertical Bandwidth Vertical Offset Zoom Full 0 volts Off To Reset the Do the following steps to reset the oscilloscope to its factory default settings Oscilloscope Selecting Channels Press the Save Recall SETUP button to display the Setup menu see Fig ure 3 3 Press the button directly below the Recall Factory Setup menu item Press the button to the right of the OK Confirm Factory Init side menu item Press the SET LEVEL TO 50 button front panel to be sure the oscilloscope triggers on the input signal The TDS Oscilloscope applies all actions based on a specific waveform such as taking measurements or applying any changes it receives to the vertical control settings to the selected waveform You can select a channel waveform a math waveform or a reference waveform This subsection describes how to select a waveform and how you can turn the display of a waveform off TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms 3 8 To Identify the Selected Channel Channel Reference Indicator 3 i OK Channel Readout gt ail 0 omv Oe ads OS el Eontliin To Select and Remove Waveforms To determine which channel is currently selected check the channel readout It shows the selected channel in inverse vi
147. data was stored If it is the oscilloscope sets status to pass if not it sets the status to Initialized If a probe has a simple oscilloscope interface the oscilloscope can usually determine if it has a different probe attenuation factor than that stored for the last Probe Cal It can also determine if the last Probe Cal was for a probe with a TEKPROBE interface If either is the case the probe installed is different from that stored for the last Probe Cal Therefore the oscilloscope sets the status to Initialized If a probe has a simple oscilloscope interface and the probe attenuation factor is the same as was stored at the last Probe Cal the oscilloscope cannot determine whether it is the same probe Therefore it displays the Re use Probe Calibration data menu See Figure 3 64 le Tek Running 100kS 5 Samp Re use Probe Cal OK Use Existing Cal Data Re use Probe Calibration data Probe cal data exists for MiA but it may not be for the attached probe To use the existing probe cal data for this probe press Use Existing Cal Data To use the probe uncalibrated and erase the existing cal data press Erase Probe Cal Data To use the probe uncalibrated while retaining OK the existing cal data for later use press Erase Probe Clear Menu ba J Cal Data chit T 00V T 00 M 500us Chi OIIO I 1 1 1 1
148. ddress configures the port for controller based system operation Use the general purpose knob or the keypad to define the address Hardcopy Talk Only configures the port for the hardcopy output without controller supervision Once so configured the oscilloscope will send the hardcopy data to any listeners on the bus when the HARDCOPY button is pressed Pressing HARDCOPY with the port configured any other way causes an error and the oscilloscope responds with a message saying the selected hardcopy port is currently unavailable Off Bus disconnects the oscilloscope from the bus TDS 684A TDS 744A amp TDS 784A User Manual 3 131 Saving Waveforms and Setups Tek Run 100kS 5 Sample GPIB Address 1 GPIB Configuration E Talk Listen ial Address GPIB Configuration Menu Hardcopy Talk Only Off Bus LOC O O Zoomy l C M 500s Chit 248mV Configure System Port ithe lt t O gt lt cpie gt Bg loloa alo Figure 3 78 Utility Menu To Find More Information See Printing a Hardcopy on page 3 120 See the TDS Programmer Manual Tektronix part number 070 8709 XX 3 132 TDS 684A TDS 744A amp TDS 784A User Manual a ame iS Sn a Determining Status and Accessing Help Displaying Status Displaying the Banner The TDS Oscilloscope can display the status of its internal systems It also provides an on
149. de menu See Figure 3 96 You can also use cursors to measure derivative waveforms Use the same procedure as is found under To Take Cursor Measurements on page 3 167 When using that procedure note that the amplitude measurements on a derivative waveform will be in volts per second rather than in volt seconds as is indicated for the integral waveform measured in the procedure TDS 684A TDS 744A amp TDS 784A User Manual 3 163 Using Features for Advanced Applications Offset Position and Scale 3 164 Tek Run 5 00MS s Average Select Measurement Nii kp 3 478KV s el Amplitude Positive Overshoot he bt panan e ear a ee a ee hee Sea tape ea es ol ONegathe L o mana n ol Overshoot Chi 200mVvaQ M 10 045 Chi 52mY TS i o DEUME 100kv s _ 10 0p 7 O i i Remove Gating 10W Reference asrmnt OFF Histagram Levels LOO ID C la Snapshot 119 10 1 1 1a Figure 3 96 Peak Peak Amplitude Measurement of a Derivative Waveform The settings you make for offset scale and position affect the math waveform you obtain Note the following tips for obtaining a good display m You should scale and position the source waveform so it is contained on screen Off screen waveforms may be clipped resulting in errors in the derivative waveform m You can use vertical position and vertical offset to posi
150. deo in the lower left corner of the display The channel reference indicator for the selected channel also appears in reverse video along the left side of the display See Figure 3 3 Tek Run 100kS 5 Sample Recall Factory LOOIDIdDiID Factory Init cat ete pe HHH LARE eee A r Saved Current Factory Utilities Setup Setup Setu 11010 1 1 1 Figure 3 3 The Channel Readout To select a channel use the channel selection buttons on the right of the display These buttons labeled CH 1 CH 2 CH 3 CH 4 and MORE select a channel and display it if its off The MORE button allows you to select internally stored Math and Ref waveforms for display and manipulation The selected channel is indicated by the lighting the LED above the button of the selected channel Do the following steps to first display and then remove waveforms from the display 1 Press CH 1 CH 2 CH 3 or CH 4 to turn on as many of these channels as desired The one you select last or first if you only select one becomes the selected channel Selecting a channel turns it on if it is not already on You do not use the channel selection buttons to select the trigger source Instead you select the trigger source in the Main Trigger menu or Delayed Trigger menu 2 Press WAVEFORM OFF to turn OFF the display of the selected channel waveform It
151. des and Trigger Holdoff on page 3 51 You can also time qualify a pattern logic trigger That is you specify a time that the boolean logic function AND NAND OR or NOR must be TRUE logic high To specify the time limit as well as the type of time qualification greater or less than the time limit specified for a pattern trigger do the following steps 1 Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt Pattern pop up gt Trigger When main gt TRUE for less than or TRUE for more than side 2 Use the knob and keypad to set the time in the side menu When you select TRUE for less than and specify a time the input conditions you specify must drive the logic function high TRUE for less than the time you specify Conversely the TRUE for more than menu item requires the boolean function to be TRUE for longer than the time you specify Note the position of the trigger indicator in Figure 3 41 Triggering occurs at the point that the oscilloscope determines that the logic function you specify is TRUE within the time you specify The oscilloscope determines the trigger point in the following manner m It waits for the logic condition to become TRUE m It starts timing and waits for the logic function to become FALSE TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms m It compares the times and if the time TRUE is longer for TRUE for more than or shorter for TRUE fo
152. determined in the following manner 1 The first MidRefCrossing MCrossI Target and third MCross3 in the source target waveform are found 2 The period of the target waveform is calculated see Period above 3 The first MidRefCrossing MCross1Ref in the reference waveform crossing in the same direction polarity as that found MCross1 Target for the target waveform is found 4 The phase is determined by the following TDS 684A TDS 744A amp TDS 784A User Manual B 9 Appendix B Algorithms Positive Duty Cycle Positive Overshoot Positive Width Rise Time aa B 10 _ MCrosslRef MCross1Target x Phase Period 360 If the target waveform leads the reference waveform phase is positive if it lags negative Phase is not available in the Snapshot display Timing measurement The ratio of the positive pulse width to the signal period expressed as a percentage PositiveWidth is defined in Positive Width following If Period 0 or undefined then return an error PositiveWidth 1090 PositiveDutyCycle Period Amplitude voltage measurement Max High Amplitude mee PositiveOvershoot Note that this value should never be negative Timing measurement The distance time between MidRef default 50 amplitude points of a positive pulse If MCross1Polarity then PositiveWidth MCross2 MCross1 else PositiveWidth MCross3
153. display reference waveforms The oscilloscope can display up to 11 waveforms at one time That includes waveforms from the four input channels four reference waveforms and three math waveforms You can save any combination of different size waveform records You will find saving waveforms useful when working with many waveforms and channels If you have more waveforms than you can display you can save one of the waveforms and then stop acquiring it By doing so you free an input channel to display another waveform without losing the first one To save a waveform do the following steps 1 Select the channel that has the waveform you want to save STOP Before doing step 2 that follows note that if you choose a reference memory location labeled active see Figure 3 66 you will overwrite the waveform that was previously stored there You can store waveforms in reference locations labeled empty without disturbing previously stored waveforms 2 To store a waveform internally press SAVE RECALL WAVEFORM gt Save Wfm main gt To Ref1 To Ref2 To Ref3 or To Ref4 side 3 To store a waveform to disk press To File side Then use the general purpose knob to select the exact file from the resulting scrollbar list Finally press Save To Selected File side to complete the operation NOTE Upon power on the oscilloscope creates the wild card file waveform in a uniquely named sequentially numbered file For in
154. dth Triggering Press TRIGGER MENU Type main gt Pulse pop up gt Class main gt Width pop up Select the Source Press TRIGGER MENU gt Type main gt Pulse pop up gt Source main gt Ch1 Ch2 Ch3 or Ch4 side The source selected becomes the trigger source for all four trigger classes Select the Polarity Press TRIGGER MENU gt Type main gt Pulse pop up Class main gt Width pop up gt Polarity main gt Positive or Negative side TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms Set to Trig When To set the range of widths in units of time the trigger source will search for and to specify whether to trigger on pulses that are outside this range or within this range do the following steps 1 Press TRIGGER MENU gt Type main gt Pulse pop up gt Class main gt Width pop up gt Trig When main 2 Press Within Limits side if you want the oscilloscope to trigger on pulses that fall within the specified range If you want it to trigger on pulses that are outside the range then press Out of Limits side 3 To set the range of pulse widths in units of time press Upper Limit side and Lower Limit side Enter the values with the general purpose knob or keypad The Upper Limit is the maximum valid pulse width the trigger source will look for The Lower Limit is the minimum valid pulse width The oscilloscope will always force the Lower Limit to be
155. e Tektronix TDS 684A SAREES a APPUCATION g MENU ACQUIRE MEX MEASURE HARDCOPY RUN STOP CO CO Cc umu ST CURSOR DISPLAY st Co CGC Co ME A HORIZONTAL gt 4a Aa Say l HORIZONTAL ZOOM MENU Cc amp SINGLE TRIG FORCE TRIG 200mv lt M10 0ns Chi F 4mv Co Comer t j Ne vous mi ource coupia siope MEA am O ee lt Edge gt Lor Holdoff a OOo 5 A eE ao ay Tek Run 5 00GS s Sample Trigger Level 4mv E F am Set to TTL Set to ECL Set to 50 2 Press one of these buttons to select from main menu 3 Press one of these buttons to select from side menu if displayed 4 if side menu item has an adjustable value shown in reverse video adjust it with the general purpose knob or keypad TDS 684A TDS 744A amp TDS 784A User Manual 2 7 Operating Interface Maps To Operate a Pop Up Menu COLOR FOUR CHANNEL DIGITIZING OSCILLOSCOPE Tektronix TDS 684A Tek Run 100kKS 5 Sample E F Edge Source AnH 280mMY more 1 of 2 M 500ums Chi Logic Pulse Level oge video Source Coupling Slope Type BC
156. e If you enable both autosave and single sequence the oscilloscope will save all live channels to reference waveforms at the completion of each single sequence event All previous reference waveform data will be erased 3 116 TDS 684A TDS 744A amp TDS 784A User Manual Saving Waveforms and Setups To rearm the oscilloscope for taking a new autosave single acquisition sequence press RUN STOP To avoid loss of reference waveforms you can save them to floppy disk use the SAVE RECALL WAVEFORM menu before rearming the oscilloscope Consider the following operating characteristics when using autosave m Autosave saves all live waveforms that is waveforms displayed in CH 1 CH 4 To be saved the live waveforms must be displayed on screen m Autosave saves each live waveform into the reference memory that corresponds to the channel CH 1 to Refl CH 2 to Ref2 and so on m Autosave when executing erases all four reference memories To avoid loss of important waveforms you may want to save them to a floppy disk file before enabling a single acquisition sequence Autosave is not available in InstaVu mode TDS 700A models only see Incompatible Modes on page 3 45 To Run the File Utilities To run file utilities see the Managing the File System on page 3 117 Managing the File System The TDS Oscilloscope provides file utilities and a floppy disk drive for saving hardcopies setups and waveforms This subse
157. e 3 126 Date Time Stamp the Hardcopy You can display the current date and time on screen so that they appear on the hardcopies you print To date and time stamp your hardcopy do the following steps 1 Press DISPLAY gt Settings main gt Display pop up gt Readout Options main gt Display Date and Time side to toggle the setting to On 2 If you want to set the date and time skip steps 3 and 4 and continue with step 1 of Set the Date and Time below Then redo this procedure 3 Press Clear Menu to remove the menu from the display so the date and time can be displayed See Figure 3 72 The date and time are removed from the display when menus are displayed 4 Once the oscilloscope is connected to a hardcopy device press HARDCO PY to print your date time stamped hardcopy TDS 684A TDS 744A amp TDS 784A User Manual 3 123 Saving Waveforms and Setups Tek Run 100kKS 5 Sample LOJO C C O win Zoom sos CAT OW 25 Mar 1994 08 39 47 ICICI C lo Date and Time Display Figure 3 72 Date and Time Display Set the Date and Time You might need to set the date and time of the oscillo scope To set those parameters do the following steps 1 Press SHIFT gt UTILITY gt Config pop up gt Set Date amp Time main gt Year Day Month Hour or Minute side 2 Use the general purpose knob
158. e Delayed Triggers Work 00005 Delayed Trigger Menu ccceccccsccscees Graticule Cursor and Automated Measurements Measurement Readouts cece reece eee Measure Menu ccc cece cece cece cree E Measure Menu Gating cc cee csececnes Measure Menu Reference Levels Measure Delay Menu Delay To Snapshot Menu and Readout eeeeee Cursor Types Cursor Modes H Bars Cursor Menu and Readouts Paired Cursor Menu and Readouts Performing a Signal Path Compensation Probe Cal Menu and Gain Compensation Display Re use Probe Calibration Data Menu Save Recall Setup Menu ccc ce ceececcees Save Waveform Menu cece cece cee eeees More Menu File Utilities File System Labeling Menu 0 Utility Menu System I O Hardcopy Formats Date and Time Display Connecting the Oscilloscope Directly to the Connecting the Oscilloscope and Typical GPIB Network Configuration Stacking GPIB Connectors Connecting the Oscilloscope to a Controller Utility Menu is aoe sias eurenean eid sais 8e a sowie ss Status Menu System Banner Display cc ccc ccc secs ccsccscees Initial Help Screen Comparing a Waveform to a Limit Template TDS 684A TDS 744A amp TDS 784A User Manual 3 127 3 129 3 130 3 131 3 132 3 134 3 134 3 135 3 137 Table of Contents vi Figure 3
159. e More main menu Press CURSOR Mode main gt Independent side gt Func tion main gt H Bars side Use the general purpose knob to align the selected cursor solid line to the top or to any amplitude on the waveform you choose Press SELECT to select the other cursor Use the general purpose knob to align the selected cursor to the bottom or to any amplitude on the waveform you choose Read the amplitude between the two cursors from the A readout Read the amplitude of the selected cursor relative to either 1 Vrms 0 dB ground 0 volts or the zero phase level 0 degrees or 0 radians from the readout The waveform reference indicator at the left side of the graticule indicates the level where phase is zero for phase FFTs Figure 3 89 shows the cursor measurement of a frequency magnitude on an FFT The readout reads 0 dB because it is aligned with the 1 Vgms level The A readout reads 24 4 dB indicating the magnitude of the frequency it is measuring is 24 4 dB relative to 1 Vrms The source waveform is turned off in the display The cursor units will be in dB or volts for FFTs measuring magnitude and in degrees or radians for those FFTs measuring phase The cursor unit depends on the selection made for Set FFT Vert Scale to side See step 7 on page 3 147 for more information Press V Bars side Use the general purpose knob to align one of the two vertical cursors to a point of interest along the ho
160. e Oscilloscope Directly to the Hardcopy Device Print To print a single hardcopy or send additional hardcopies to the oscilloscope spool queue while waiting for earlier hardcopies to finish printing press HARDCOPY While the hardcopy is being sent to the printer the oscilloscope will display the message Hardcopy in process Press HARDCOPY to abort Abort To stop and discard the hardcopy being sent press HARDCOPY again while the hardcopy in process message is still on screen Add to the Spool To add additional hardcopies to the printer spool press HARDCOPY again after the hardcopy in process message is removed from the screen You can add hardcopies to the spool until it is full When adding a hardcopy fills the spool the message Hardcopy in Process Press HARDCOPY to abort remains displayed You can abort only the last hardcopy sent by pressing the button while the message is still displayed When the printer empties enough of the spool to finish adding the last hardcopy it does so and then removes the message TDS 684A TDS 744A amp TDS 784A User Manual 3 125 Saving Waveforms and Setups To Save to a Floppy Disk 3 126 Clear the Spool To remove all hardcopies from the spool press SHIFT gt HARDCOPY MENU gt Clear Spool main gt OK Confirm Clear Spool side The oscilloscope takes advantage of any unused RAM when spooling hardcopies to printers The size of the spool is therefore variable
161. e cursor but places other magnitudes completely below the cursor 3 Read the level in dB from the readout Note the level for use in step 5 4 Press MORE main gt Change Waveform Definition menu side Press Set FFT Vert Scale to side repeatedly to choose either Phase rad or Phase deg 5 Press Suppress Phase at Amplitudes side Use the general purpose knob to set phase suppression to the value obtained using the H Bar cursor Do not change the window selection or you will invalidate the results obtained using the cursor TDS 684A TDS 744A amp TDS 784A User Manual 3 157 Using Features for Advanced Applications 3 158 FFT Windows To learn how to optimize your display of FFT data read about how the FFT windows data before computing the FFT math waveform Understanding FFT windowing can help you get more useful displays Windowing Process The oscilloscope multiplies the FFT time domain record by one of four FFT windows before it inputs the record to the FFT function Figure 3 93 shows how the time domain record is processed The FFT windowing acts like a bandpass filter between the FFT time domain record and the FFT frequency domain record The shape of the window controls the ability of the FFT to resolve separate the frequencies and to accurately measure the amplitude of those frequencies Selecting a Window You can select your window to provide better frequency resolution at the expense of better ampli
162. e measure ments May be calculated using either the min max or the histogram method With the min max method most useful for general waveforms it is the minimum value found With the histogram method most useful for pulses it refers to the most common value found below the mid point See Appendix B Algorithms for details Main menu A group of related controls for a major oscilloscope function that the oscilloscope displays across the bottom of the screen Main menu buttons Bezel buttons under the main menu display They allow you to select items in the main menu Maximum Amplitude voltage measurement of the maximum amplitude Typically the most positive peak voltage Mean Amplitude voltage measurement of the arithmetic mean over the entire waveform Minimum Amplitude voltage measurement of the minimum amplitude Typically the most negative peak voltage NAND A logic Boolean function in which the output of the AND function is complemented true becomes false and false becomes true On the oscilloscope that is a trigger logic pattern and state function Negative duty cycle A timing measurement representing the ratio of the negative pulse width to the signal period expressed as a percentage TDS 684A TDS 744A amp TDS 784A User Manual Glossary 7 gt Negative overshoot measurement Amplitude voltage measurement Low Min Amplitude ae NegativeOve
163. e since the last Probe Cal was performed Some Probes Cannot Be Compensated Some types of probes can be gain compensated some can be offset compensated and some can be compensated for both Some probes cannot be compensated at all Note the following restrictions m The oscilloscope cannot compensate probes that have an attenuation factor of greater than 20X If you attempt to compensate such a probe you will get an error message m The oscilloscope cannot compensate probes that have gain and or offset errors that are too great gt 2 gain and or gt 50 mV offset If these errors are within specified limits for your probe you may want to use another probe If they are not within specification have your probe checked by service personnel TDS 684A TDS 744A amp TDS 784A User Manual Measuring Waveforms NOTE Probe Cal is not recommended with the P6139A passive probe This probe typically has little gain and offset error and therefore the improvement in performance after a Probe Cal is not worth the time needed to do the Probe Cal Probe Cal makes significant performance improvements when performed with active probes or older passive probes To run a probe cal follow the instructions regarding prerequisites below and then do the steps that follow m If you are installing an active probe such as the P6245 there are no prerequisites to performing this procedure Start at step 1 m If you are compensating for a pass
164. ected Envelope or Average enter the number of waveform records to be enveloped or averaged using the keypad or the general purpose knob TDS 684A TDS 744A amp TDS 784A User Manual 3 23 Acquiring and Displaying Waveforms Selecting Repetitive Sampling 3 24 NOTE TDS 700A models only Selecting Hi Res mode in the Acquire menu will automatically reduce the record length to a value that prevents overflow of acquisition memory Because Hi Res mode uses twice the acquisition memory that the other acquisition modes use allowing selection of the longer horizontal record lengths with Hi Res mode would cause the oscilloscope to run out of memory TDS 700A models only To limit the oscilloscope to real time sampling or let it choose between real time or equivalent time sampling Press SHIFT ACQUIRE MENU gt Repetitive Signal main gt ON or OFF side m ON Enable ET uses both the real time and the equivalent time sampling as appropriate OFF Real Time Only limits the oscilloscope to real time sampling If the oscilloscope cannot accurately get enough samples for a complete waveform it will interpolate The sampling speeds and the number of channels you choose affect the mode the oscilloscope uses to sample waveforms If the time base is set slow enough the oscilloscope always uses real time sampling if set fast enough it always uses equivalent time sampling or interpolation For speeds in between the oscillo sco
165. ed are taken on the channel 1 waveform You take a snapshot of a waveform in another channel by first selecting that channel using the channel selection buttons The snapshot measurements do not continuously update Snapshot executes a one time capture of all measurements and does not update those measure ments unless it is performed again Tek Run 100kS 5 Sample Snapshot aa i fa us Again j snapshot on Si Period 1 000ms Freq 1 00008kH2 Width 500ps Width 500ys Brstwd 4 500ms Rise 6MS Fall BUS Duty 50 0 Duty 50 0 Over 11 3 Over 38 1 High 504m Low SmvV Max 560mvV Min 32mvV Ampl 496mV Pk Pk 592m Mean 255 6mY CycMean 262 4m Y RMS 359 6m CycRMS 362 4m ny R Area 1 27548mV5 cycArea 262 20uUVSs MIDIC O G G LOlololo lo Figure 2 17 Snapshot of Channel 1 2 Press Again side to do another snapshot and update the snapshot measure ments TDS 684A TDS 744A amp TDS 784A User Manual 2 23 Tutorial 3 Press Remove Measrmnt main to remove the snapshot display You can also press CLEAR MENU but a new snapshot will be executed the next time you display the Measure menu Example 4 Saving Setups The TDS Oscilloscope can save its controls settings and recall them later to quickly re establish a setup It provides ten storage locations to store
166. eform all the CH lights are turned off Press WAVEFORM OFF again to remove the channel 1 waveform Example 3 Taking Automated Measurements The TDS Oscilloscope can measure many waveform parameters automatically and read out the results on screen Do the following tasks to discover how to set up the oscilloscope to measure waveforms automatically Display Measurements To use the automated measurement system you must have a stable display of Automatically your signal Also the waveform must have all the segments necessary for the measurement you want For example a rise time measurement requires at least one rising edge and a frequency measurement needs at least one complete cycle To take automated measurements do the following steps 1 If you are not continuing from the previous example follow the instructions on page 2 9 under the heading Setting Up for the Examples Press SETUP gt Recall Factory Setup main gt OK Confirm Factory Init side Press AUTOSET Press MEASURE to display the Measure main menu See Figure 2 14 If it is not already selected press Select Measrmnt main The readout for that menu item indicates which channel the measurement will be taken from All automated measurements are made on the selected channel The Select Measurement side menu lists some of the measurements that can be taken on waveforms There are many different measurements available up to four can be taken and d
167. eform Menu To Display a To display a waveform in internal reference memory Saved Waveform Press MORE gt Ref1 Ref2 Ref3 or Ref4 main See Figure 3 67 TDS 684A TDS 744A amp TDS 784A User Manual 3 115 Saving Waveforms and Setups Note that in Figure 3 67 the main menu items Ref2 Ref3 and Ref4 appear shaded while Ref1 does not References that are empty appear shaded in the More main menu To Recall a Waveform To recall a waveform from disk to an internal reference memory press SAVE From Disk RECALL WAVEFORM gt Recall Wfm To Ref main gt Recall From File side Then use the general purpose knob to select the exact file from the resulting scrollbar list Only files with WFM extensions are displayed Finally press To Ref1 To Ref2 To Ref3 or To Ref side to complete the operation 2 Tek Run 100kKS 5 Sample Math Change Math waveform definition No Extended mee Processsing Average 2 300m Math2 Math3 Chit he Chi Che inv chi DID CIO S C O Figure 3 67 More Menu To Enable Autosave To use autosave press SAVE RECALL WAVEFORM gt Autosave main gt Autosave Single Seq ON side Also turn on Single Acquisition Sequence in the Acquire menu See Stop After on page 3 25 To disable this feature simply press Autosave main Autosave Single Seq OFF sid
168. eform record points it generally gives the best frequency resolution because it results in the most narrow lobe width in the FFT output record If the time domain records you measured always had an integer number of cycles you would only need this window Hamming Hanning and Blackman Harris are all somewhat bell shaped widows that taper the waveform record at the record ends The Hanning and Blackman Harris windows taper the data at the end of the record to zero therefore they are generally better choices to eliminate leakage TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications al hn Rectangular Window Hamming Window SN Hanning Window Blackman Harris Window Figure 3 94 FFT Windows and Bandpass Characteristics Care should be taken when using bell shaped windows to be sure that the most interesting parts of the signal in the time domain record are positioned in the center region of the window so that the tapering does not cause severe errors Waveform Differentiation The Advanced DSP Math capabilities of the TDS Oscilloscope include waveform differentiation This capability allows you to display a derivative math waveform that indicates the instantaneous rate of change of the waveform acquired This section describes how to setup the oscilloscope to display and measure derivative math waveforms TDS 684A TDS 744A amp TDS 784A User Manual 3 161 Using Features for Ad
169. ejection High Frequency Rejection and Noise Rejection See To Specify Coupling on page 3 58 for a description of each coupling mode Trigger Position The adjustable feature trigger position defines where on the waveform record the trigger occurs It lets you properly align and measure data within records The part of the record that occurs before the trigger is the pretrigger portion The part that occurs after the trigger is the posttrigger portion I To help you visualize the trigger position setting the top part of the display has an icon indicating where the trigger occurs in the waveform record You select in the Horizontal menu what percentage of the waveform record will contain pretrigger information TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms Displaying pretrigger information can be valuable when troubleshooting For example if you are trying to find the cause of an unwanted glitch in your test circuit it might trigger on the glitch and make the pretrigger period large enough to capture data before the glitch By analyzing what happened before the glitch you may uncover clues about its source Slope and Level The slope control determines whether the oscilloscope finds the trigger point on the rising or the falling edge of a signal See Figure 3 32 AL NA You set trigger slope by first selecting Slope in the Main Trigger menu and then selecting between the rising or falling slope icons i
170. el combinations But before you do so be sure you take note of the following requirements m Remember to first low frequency compensate any passive probe you connect see the prerequisites listed on page 3 105 at the beginning of this procedure m Remember to connect all but simple passive probes to the oscilloscope for a twenty minute warm up before running Probe Cal Changing Probes After a Probe Cal If a Probe Cal has never been performed on an input channel or if its stored Probe Cal data is erased using the Re use Probe Calibration Data menu discussed later the oscilloscope displays Initialized status in its vertical menu It also displays initialized whenever you remove a probe from an input If you execute a successful Probe Cal on an input channel the oscilloscope stores the compensation data it derived in nonvolatile memory Therefore this data is available when you turn the oscilloscope off and back on and when you change probes TDS 684A TDS 744A amp TDS 784A User Manual 3 107 Measuring Waveforms 3 108 When you install a probe or power on the oscilloscope with probes installed the oscilloscope tests the probe at each input Depending on the probe it finds on each input it takes one of the following actions If the probe has a TEKPROBE interface such an interface can convey additional information such as a unique identification number the oscilloscope determines whether it is the same probe for which
171. election ccc ccc cccc ccs scsccees E 1 TDS 684A TDS 744A amp TDS 784A User Manual Table of Contents List of Figures Figure 1 1 Rear Panel Controls Used in Start Up 1 4 Figure 1 2 ON STBY Button ccc cece ccc c cece eeeens 1 5 Figure 2 1 Connecting a Probe for the Examples P6245 shown 2 9 Figure 2 2 SETUP Button Location cece eee eee 2 10 Figure 2 3 The Setup Menu cece ecccceccccccsccsces 2 10 Figure 2 4 Trigger Controls cece cece ccc ce ccs ceeees 2 11 Figure 2 5 The Display After Factory Initialization 2 12 Figure 2 6 The VERTICAL and HORIZONTAL Controls 2 13 Figure 2 7 TRIGGER Controls 0 ccc cece ce eee ee eeee 2 14 Figure 2 8 AUTOSET Button Location 0eceeeeeee 2 14 Figure 2 9 The Display After Pressing Autoset 2 15 Figure 2 10 Display Signals Requiring Probe Compensation 2 15 Figure 2 11 The Channel Buttons and Lights 2 16 Figure 2 12 The Vertical Main Menu and Coupling Side Menu 2 17 Figure 2 13 The Menus After Changing Channels 2 18 Figure 2 14 Measure Main Menu and Select Measurement Side Menu vecssirecsetisoerieri pme tai WE ghee ele Oo ee a ww les 2 20 Figure 2 15 Four Simultaneous Measurement Readouts 2 21 Figure 2 16 General Purpose Knob Indicators 2 22 Figure 2 17 Snapshot of Channel 1
172. election Current Probes E 4 precisely connect your instrument to your device under test These probes have the same electrical characteristics as high speed active probes but use a smaller mechanical design Current probes enable you to directly observe and measure current waveforms which can be very different from voltage signals Tektronix current probes are unique in that they can measure from DC to 1 GHz Two types of current probes are available one that measures AC current only and AC DC probes that utilize the Hall effect to accurately measure the AC and DC components of a signal AC only current probes use a transformer to convert AC current flux into a voltage signal to the oscilloscope and have a frequency response from a few hundred Hertz up to 1 GHz AC DC current probes include Hall effect semiconductor devices and provide frequency response from DC to 50 MHz Use a current probe by clipping its jaws around the wire carrying the current that you want to measure Unlike an ammeter which you must connect in series with the circuit Because current probes are non invasive with loading typically in the milliohm to low Q range they are especially useful where low loading of the circuit is important Current probes can also make differential measurements by measuring the results of two opposing currents in two conductors in the jaws of the probe Figure E 2 A6303 Current Probe Used in the AM 503S Opt 03 TDS 684A
173. els Set Levels in units 248mV EEEE Co C C Figure 3 55 Measure Menu Reference Levels TDS 684A TDS 744A amp TDS 784A User Manual LOJO C C O 3 93 Measuring Waveforms 2 Press High Ref Mid Ref Low Ref or Mid2 Ref side High Ref Sets the high reference level The default is 90 Mid Ref Sets the middle reference level The default is 50 Low Ref Sets the low reference level The default is 10 TE Mid2 Ref Sets the middle reference level used on the second waveform specified in the Delay or Phase Measurements The default is 50 Take a Delay The delay measurement lets you measure from an edge on the selected waveform Measurement to an edge on another waveform To take a delay measurement do the following steps 1 Press MEASURE gt Select Measrmnt main gt Delay side gt Delay To main gt Measure Delay to 2 Press Measure Delay to side repeatedly to choose the delay to waveform The choices are Ch1 Ch2 Ch3 Ch4 Math1 Math2 Math3 Ref1 Ref2 Ref3 and Ref4 The steps just performed select the waveform you want to measure fo note that the waveform you are measuring delay from is the selected waveform See Figure 3 56 Tek Run 100kKS 5 sure Delay to Chl Delay from Selected Wim Measure mat to EPN T ad EAN E a
174. ement 2 is below it and so forth Once a measurement readout is displayed in the screen area it stays in its position even when you remove any measurement readouts above it To use the automatic measurements you first need to obtain a stable display of the waveform to be measured Pressing AUTOSET may help Once you have a stable display press MEASURE to bring up the Measure menu See Figure 3 53 1 Press MEASURE gt Select Measrmnt main 2 Select a measurement from the side menu Note the following rules for taking automatic measurements m You can only take a maximum of four measurements at a time To add a fifth you must remove one or more of the existing measurements m To vary the source for measurements simply select the other channel and then choose the measurements you want TDS 684A TDS 744A amp TDS 784A User Manual Measuring Waveforms m Becareful when taking automatic measurements on noisy signals You might measure the frequency of the noise and not the desired waveform Your oscilloscope helps identify such situations by displaying a low signal amplitude or low resolution warning message a Tek Run 100kKS 5 Sample Select Measurement Frequency Positi widt Negative width 200mv mM 500us Chif 268mvV more 4 o EE Tira ter MEAE AEE Remove Gating t Reference Measrmnt Setup
175. ements 3 91 Glossary 4 Gating Measure menu 3 91 General purpose high input resistance probes E 1 General purpose knob 2 7 2 21 Glossary 4 Glitch trigger 3 71 Glossary 4 How to set up 3 72 3 86 Glitch Main Trigger menu 3 73 Goes FALSE Main Trigger menu 3 66 3 68 Index 5 Index Goes TRUE Main Trigger menu 3 66 3 68 GPIB 2 5 3 129 3 132 Glossary 4 Connecting to 3 130 Interconnect cabling 3 130 Interface requirements 3 129 Procedures for using 3 130 Protocols 3 129 Selecting and configuring the port 3 131 Typical configuration 3 129 GPIB Hardcopy menu 3 123 GPIB Utility menu 3 131 Graticule 3 31 Glossary4 Measurements 3 87 Graticule Display menu 3 31 3 48 Grid Display menu 3 31 Ground coupling Glossary 4 GROUP 1 GROUP 2 buttons 3 38 H H Bars Cursor menu 3 99 3 100 H Limit Acquire menu 3 139 Hamming window 3 148 Hanning window 3 148 Hardcopy 3 120 3 132 Glossary 4 How to print controller 3 127 How to print no controller 3 125 How to save to disk 3 126 How to set up for 3 122 Printing a hardcopy 3 120 Spool 3 125 3 126 Hardcopy Talk Only Utility menu 3 122 HARDCOPY button 3 117 3 122 3 131 Hardcopy if Condition Met Acquire menu 3 140 Hardcopy menu BMP Color 3 122 BMP Mono 3 122 Clear Spool 3 122 3 126 Deskjet 3 122 DPU411 II 3 122 DPU412 3 122 EPS Color Img 3 122 EPS Color Plt 3 122 EPS
176. en or optionally outside the user speci fied lower and upper time limits Slew Positive Slew Negative Slew either Triggering occurs if the oscilloscope detects a positive pulse edge that after first crossing the lower threshold then crosses the upper threshold The pulse must travel between the two levels ata rate faster or slower than user specifies the user specified slew rate for triggering to occur a Triggering occurs if the oscilloscope detects a negative pulse edge that after first crossing the upper threshold then crosses the lower threshold The pulse must travel between the two levels ata rate faster or slower than user specifies the user specified slew rate for triggering to occur Triggering occurs if the oscilloscope detects a positive or negative pulse edge that first crosses one threshold and then crosses the other threshold The pulse must travel between the two levels ata rate faster or slower than user specifies the user specified slew rate for triggering to occur To Trigger ona Glitch When you select the pulse class Glitch the oscilloscope will trigger on a pulse narrower or wider in width than some specified time To set up for glitch triggering do the following procedures Select Glitch Triggering Press TRIGGER MENU gt Type main gt Pulse pop up gt Class main gt Glitch pop up 3 72 TDS 684A TDS 744A amp TDS 784A User Manual Triggering
177. ents up to 40 V High voltage probes have attenuation factors in the 100X to 1000X range The considerations that apply to other passive probes apply to high voltage probes with a few exceptions Since the voltage range on high voltage probes varies from 1 kV to 20 kV DC peak AC the probe head design is mechanically much larger than for a passive probe High voltage probes have the added advantage of lower input capacitance typically 2 3 pF Figure E 1 Typical High Voltage Probes TDS 684A TDS 744A amp TDS 784A User Manual Appendix E Probe Selection Active Voltage Probes Active voltage probes sometimes called FET probes use active circuit elements such as transistors There are three classes of active probes m High speed active m Differential active m Fixtured active Active voltage measuring probes use active circuit elements in the probe design to process signals from the circuit under test All active probes require a source of power for their operation Power is obtained either from an external power supply or from the oscilloscope itself Active voltage measuring probes use active circuit elements in the probe design to process signals from the circuit under test All active probes require a source of power for their operation Power is obtained either from an external power supply or from the oscilloscope itself NOTE When you connect an active probe to the oscilloscope such as the P6245
178. er To choose the event that signals the oscilloscope to stop acquiring waveforms do the following step Press SHIFT ACQUIRE MENU gt Stop After main gt RUN STOP button only Single Acquisition Sequence or Limit Test Condition Met side See Figure 3 15 TDS 700A models only single acquisition and limit testing are ignored in InstaVu mode see Incompatible Modes on page 3 45 Tek Run 100k5 s Stop After RUN STOP button only 4 Single 4 Acquisition Sequence Limit Test Condition Met Zoomy C M 500s Chif 248mV Mode Kuteyeeeyiteg Limit Test Limit Test amp reate Limit Test Sample e Trea Setup Sources 7 plate 11 1 1 1 1 LOO OC C O Figure 3 15 Acquire Menu Stop After TDS 684A TDS 744A amp TDS 784A User Manual 3 25 Acquiring and Displaying Waveforms 3 26 Preventing Aliasing m Press RUN STOP button only side to use the RUN STOP button to start or stop acquiring Pressing the RUN STOP button once will stop the acquisitions The upper left hand corner in the display will say Stop and show the number of acquisitions If you press the button again the oscillo scope will resume taking acquisitions Press Single Acquisition Sequence side That selection lets you run a single sequence of acquisitions by pressing the RUN STOP button In Sample Peak Detect or Hi
179. escribe how state triggers work To use state triggering do the following procedures Select State Triggering Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt State pop up Define Inputs To set the logic state for each of the input channels Ch1 Ch2 1 Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt State pop up gt Define Inputs main TDS 684A TDS 744A amp TDS 784A User Manual 3 67 Triggering on Waveforms 3 68 To Trigger on Setup Hold Time Violations 2 Choose either High H Low L or Don t Care X side for the first three channels The choices for Ch4 are rising edge and falling edge Set Thresholds To set the logic threshold for each channel 1 Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt State pop up gt Set Thresholds main gt Ch1 Ch2 Ch3 or Ch side 2 Use the MAIN TRIGGER LEVEL knob the general purpose knob or the keypad to set each threshold Define Logic To choose the type of logic function you want applied to the input channels Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt State pop up gt Define Logic main gt AND OR NAND or NOR side Set Trigger When To choose to trigger when the logic condition is met Goes TRUE or when the logic condition is not met Goes FALSE Press TRIGGER MENU gt Type main gt Logic pop
180. essing Intensified side you can display an intensified zone that shows where the delayed timebase record may occur a valid delay trigger event must be received relative to the main trigger on the main time base For Delayed Triggerable After mode the start of the intensified zone corresponds to the possible start point of the delayed time base record The end of the zone continues to the end of main time base since a delayed time base record may be triggered at any point after the delay time elapses To learn how to define the intensity level of the normal and intensified waveform see Adjust Intensity on page 3 29 Now you need to bring up the Delayed Trigger menu so that you can define the delayed trigger event Press SHIFT DELAYED TRIG gt Delay by main gt Triggerable After Time Events or Events Time side See Figure 3 50 Tek Run 50 0MS s Sample Delay by Time 16ns Delayed Edge Delay im ef Triggerable after Time Events i PA Events Time Time 7 M 200us Chis 304mv v Events D1 00us Chi 304mv 2 Delay by Source Coupling Slope Level Time ch DC f 304mV LOJO CO OC PIG ICICI IC Figure 3 50 Delayed Trigger Menu 7 Enter the delay time or events using the general purpose knob or the keypad If you selected Events Time use Time side and Events side to switch between setting the
181. et 3 124 DC coupling Glossary 3 DC offset 3 153 for DC correction of FFTs 3 153 Index 3 Index with math waveforms 3 153 3 169 DC Main Trigger menu 3 58 Define Inputs Main Trigger menu 3 65 3 67 3 69 Define Logic Main Trigger menu 3 66 3 68 Delay by Events Delayed Trigger menu 3 84 Delay by Time Delayed Trigger menu 3 84 Delay by Delayed Trigger menu 3 84 Delay measurement 3 94 Glossary 3 Delay time Glossary 3 Delay To Measure Delay menu 3 94 Delayed Only Horizontal menu 3 83 Delayed Runs After Main 3 53 3 86 Delayed Runs After Main Horizontal menu 3 16 3 83 Delayed Scale Horizontal menu 3 15 Delayed time base Incompatible with InstaVu 3 46 DELAYED TRIG button 3 53 3 83 Delayed trigger 3 53 3 86 How to set up 3 83 Delayed Trigger menu 3 83 3 86 Chi Ch2 3 85 Coupling 3 85 Delay by 3 84 Delay by Events 3 84 Delay by Time 3 84 Falling edge 3 85 Level 3 85 Rising edge 3 85 Set to 50 3 85 Set to ECL 3 85 Set to TTL 3 85 Slope 3 85 Source 3 85 DELAYED TRIGGER OUTPUT BNC 2 5 Delayed Triggerable 3 53 3 86 Delayed Triggerable Horizontal menu 3 16 3 83 Delete Refs Save Recall Waveform menu 3 115 Delete File Utilities menu 3 118 Delta Time Main Trigger menu 3 78 Derivative math waveform 3 162 applications 3 162 derivation of 3 162 procedure for displaying 3 162 procedure for meas
182. et the selected level while the Main Trigger menu is set to Logic When you select the logic class Pattern the oscilloscope will trigger on a specified logic combination of the four input channels Pages 3 60 through 3 62 describe how pattern triggers work To use pattern triggering do the procedures that follow Select Pattern Triggering Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt Pattern pop up TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms Tek Run 100kKS 5 Sample chi GL X 4 Logic Pattern Inputs Edge E ane ee a eee Se T Logic o O M S00ms Pattern Hxxx O Pulse OII o video mai E H R a a me Ear z ger ge 2 ode Type Class tho te Logic when hice hold amp stogic gt lt Pattern gt AND Goes TRUE Holdoff e Figure 3 40 Logic Trigger Menu To Define Pattern Inputs To set the logic state for each of the input channels Ch1 Ch2 1 Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt Pattern pop up gt Define Inputs main gt Ch1 Ch2 Ch3 or Ch side 2 Repeatedly press each input selected in step to choose either High H Low L or Don t Care X for each channel To Set Thresholds To set the logic threshold for each channel 1 Press TRIGGER MENU gt Type main g
183. etected can be positive negative or either Sample acquisition mode The oscilloscope creates a record point by saving the first sample during each acquisition interval That is the default mode of the acquisition Sample interval The time interval between successive samples in a time base For real time digitizers the sample interval is the reciprocal of the sample rate For equivalent time digitizers the time interval between successive samples represents equivalent time not real time Sampling The process of capturing an analog input such as a voltage at a discrete point in time and holding it constant so that it can be quantized Two general methods of sampling are real time sampling and equivalent time sampling Setup Hold trigger A mode in which the oscilloscope triggers when a data source changes state within the setup or hold time relative to a clock source Positive setup times precede the clock edge positive hold times follow the clock edge The clock edge may be the rising or falling edge Select button A button that changes which of the two cursors is active TDS 684A TDS 744A amp TDS 784A User Manual Glossary 9 Glossary Glossary 10 Selected waveform The waveform on which all measurements are performed and which is affected by vertical position and scale adjustments The light over one of the channel selector buttons indicates the current selected waveform Side menu Menu that appears to the right o
184. f refer to Set Mode amp Holdoff on page 3 59 To learn more about trigger mode and holdoff see Trigger Modes and Trigger Holdoff on page 3 51 The TDS Oscilloscope provides a main time base and a delayed time base The delayed time base like the main time base requires a trigger signal and an input source dedicated to that signal You can only use delay with respect to the main TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms Delayed Triggerable After Time Delayed Triggerable After Events Delayed Triggerable After Events Time TDS 684A TDS 744A amp TDS 784A User Manual edge trigger and certain classes of main pulse triggers This subsection describes how to delay the acquisition of waveforms The Delayed time base is not available in InstaVu mode TDS 700A models only see Incompatible Modes on page 3 45 There are two different ways to delay the acquisition of waveforms delayed runs after main and delayed triggerable Only delayed triggerable uses the delayed trigger system Delayed runs after main looks for a main trigger then waits a user defined time and then starts acquiring See Figure 3 47 Acquire Data Delayed triggerable looks for a main trigger and then depending on the type of delayed trigger selected makes one of the three types of delayed triggerable mode acquisitions After Time After Events or After Events Time Study Figure 3 48 to understand the sequence the oscill
185. f the display These selections expand on main menu selections Side menu buttons Bezel buttons to the right of the side menu display They allow you to select items in the side menu Slew Rate trigger A mode in which the oscilloscope triggers based on how fast a pulse edge traverses slews between an upper and lower threshold The edge of the pulse may be positive negative or either The oscilloscope can trigger on slew rates faster or slower than a user specified rate Slope The direction at a point on a waveform You can calculate the direction by computing the sign of the ratio of change in the vertical quantity Y to the change in the horizontal quantity The two values are rising and falling Tek Secure This feature erases all waveform and setup memory locations setup memories are replaced with the factory setup Then it checks each location to verify erasure This feature finds use where this oscilloscope is used to gather security sensitive data such as is done for research or development projects Time base The set of parameters that let you define the time and horizontal axis attributes of a waveform record The time base determines when and how long to acquire record points Trigger An event that marks time zero in the waveform record It results in acquisi tion and display of the waveform Trigger level The vertical level the trigger signal must cross to generate a trigger on edge trigger mode Vertical
186. find a list of available probes see Accessory Probes on page A 4 To find a guide for selecting probes for a variety of applications see Appen dix E Probe Selection on page E 1 Setting up Automatically Autoset and Reset The TDS Oscilloscope can automatically obtain and display a stable waveform of usable size It can also be reset to its factory default settings This subsection describes how to execute Autoset and reset and lists the default settings in effect after an Autoset Autoset automatically sets up the front panel controls based on the characteristics of the input signal It is much faster and easier than a manual control by control setup Autoset adjusts controls in these categories Acquisition Display Horizontal Trigger and Vertical TDS 684A TDS 744A amp TDS 784A User Manual 3 5 Acquiring and Displaying Waveforms 3 6 To Autoset the Oscilloscope List of Autoset Defaults Do the following steps to automatically set up the oscilloscope 1 Press the channel selection button such as CH 1 corresponding to your input channel to make it active 2 Press AUTOSET If you use Autoset when one or more channels are displayed the oscilloscope selects the lowest numbered channel for horizontal scaling and triggering Vertically all channels in use are individually scaled If you use Autoset when no channels are displayed the oscilloscope will turn on channel one CH 1 and scale it NOTE Auto
187. find use in the following applications m Measuring of power and energy such as in switching power supplies m Characterizing mechanical transducers as when integrating the output of an accelerometer to obtain velocity TDS 684A TDS 744A amp TDS 784A User Manual 3 165 Using Features for Advanced Applications To Create a Integral Math Waveform 3 166 The integral math waveform derived from the sampled waveform is computed based on the following equation n y n scale gt L Dy i l Where x i is the source waveform y n is a point in the integral math waveform scale is the output scale factor T is the time between samples Since the resultant math waveform is an integral waveform its vertical scale is in volt seconds its horizontal scale is in seconds The source signal is integrated over its entire record length therefore the math waveform record length equals that of the source waveform To obtain an integral math waveform do the following steps 1 Connect the waveform to the desired channel input and select that channel 2 Adjust the vertical and horizontal scales and trigger the display or press AUTOSET 3 Press MORE Math1 Math2 or Math3 main gt Change Math waveform definition side gt Single Wfm Math main 4 Press Set Single Source to side Repeatedly press the same button until the channel source selected in step 1 appears in the menu label 5 Press Set Function to side
188. finite Persistence and Variable Persistence in the side menu Variable Persistence is the factory default setting 4 Use the general purpose knob or keypad to adjust the persistence time decay rate if you have selected Variable Persistence To Set the InstaVu To change the InstaVu readout options do the following steps Readout Options Press DISPLAY Mode main gt InstaVu pop up gt Readout Options main 2 Toggle Display T Trigger Point Trigger Bar Style and Display Date Time in the side menu to the settings desired Incompatible Modes Several modes features are unavailable when InstaVu mode is selected Auto trigger FastFrame Limit Testing XY display and Zoom modes TDS 684A TDS 744A amp TDS 784A User Manual 3 45 Acquiring and Displaying Waveforms m Envelope Average Hi Res and Single Acquisition Sequence acquisition modes and Autosave mode m Delayed time base m Record lengths longer than 500 samples m Interpolation equivalent time sampling is used instead m Vectors when in equivalent time mode waveforms are displayed as Dots instead To determine under what conditions the oscilloscope normally interpolates or uses equivalent time see Selecting Repetitive Sampling on page 3 24 If you select any of these modes before or while InstaVu is on they will remain selected in their respective menus but the oscilloscope will ignore them It will put the modes into effect when you turn InstaVu
189. forms TDS 684A TDS 744A amp TDS 784A User Manual 3 63 Triggering on Waveforms To Check Logic Trigger Status To Trigger on a Pattern 3 64 of Figure 3 38 The oscilloscope can then detect and trigger on violations of a time range that occurs before or one that occurs after the clock NOTE Keep hold time to at least 2 ns less than the clock period or the oscillo scope cannot trigger To quickly check if logic triggers are selected and if so what class check the Trigger readout When logic triggers are selected the trigger readout displays the selected logic trigger class Pattern State or StlHld Setup Hold See Figure 3 39 Ch 1 2 3 Inputs High Don t Care High Ch 4 Input Rising Edge Trigger Class S tate Logic OR i i i U Edge i EEI omy O M S00us State HKS S 0 ulse E Sa PEE a A O ee video EEE EEE EASE FEN ELEA LEAT n Define rae Set ue ype Class Inputs when amp lt Logic gt lt State gt Goes TRUE Holdoff ea Figure 3 39 Logic Trigger Readouts State Class Selected NOTE When the trigger type Logic is selected the trigger levels must be set for each channel individually in the Set Thresholds menu pattern and state classes or the Levels setup hold class menu Therefore the Trigger Level readout will disappear on the display and the Trigger Level knob can be used to s
190. frequencies try the Hamming window before settling on the rectangular window Depending on the distance of the frequencies you are trying to measure from the fundamental the Hamming window sometimes resolves frequencies better than the Hanning TDS 684A TDS 744A amp TDS 784A User Manual 3 159 Using Features for Advanced Applications 3 160 Window Characteristics When evaluating a window for use you may want to examine how it modifies the FFT time domain data Figure 3 94 shows each window its bandpass characteristic bandwidth and highest side lobe Consider the following characteristics m The narrower the central lobe for a given window the better it can resolve a frequency m The lower the lobes on the side of each central lobe are the better the amplitude accuracy of the frequency measured in the FFT using that window m Narrow lobes increase frequency resolution because they are more selective Lower side lobe amplitudes increases accuracy because they reduce leakage Leakage results when the time domain waveform delivered to the FFT function contains a non integer number of waveform cycles Since there are fractions of cycles in such records there are discontinuities at the ends of the record These discontinuities cause energy from each discrete frequency to leak over on to adjacent frequencies The result is amplitude error when measuring those frequencies The rectangular window does not modify the wav
191. general purpose knob has just been set to adjust a parameter m The upper right corner of the screen shows the readout High Ref 90 m The High Ref side menu item is highlighted and a box appears around the 90 readout in the High Ref menu item The box indicates that the general purpose knob is currently set to adjust that parameter Turn the general purpose knob left and right and then use it to adjust the high level to 80 That sets the high measurement reference to 80 TDS 684A TDS 744A amp TDS 784A User Manual 2 21 Tutorial 2 22 Hint To make large changes quickly with the general purpose knob press the SHIFT button before turning the knob When the light above the SHIFT button is on and the display says Coarse Knobs in the upper right corner the general purpose knob speeds up significantly General Purpose Knob Setting and Readout i sean onae ain DanS General e x a Reference Knob Icon Leve Set Levels in x units 0 Highlighted Menu Item with Boxed Readout Value Low 7 resolution ic hit zoomy i a a M Soins chi 248mV pa Remove Gating 1g Reference Measrmnt getup Snapshot forech Measrmnt OFF Histogram Levels 11 1 1a Figure 2 16 General Purpose Knob Indicators The Numeric Keypad Any time the general purpose knob is set to adjust a numeric pa
192. ger Triggering occurs if the oscilloscope detects negative spike widths less than the specified glitch time Glitch either trigger Triggering occurs if the oscilloscope detects either positive or negative spike widths less than the specified glitch time GPIB General Purpose Interface Bus An interconnection bus and protocol that allows you to connect multiple instruments in a network under the control of a controller Also known as IEEE 488 bus It transfers data with eight parallel data lines five control lines and three handshake lines Graticule A grid on the display screen that creates the horizontal and vertical axes You can use it to visually measure waveform parameters Ground GND coupling Coupling option that disconnects the input signal from the vertical system Hardcopy An electronic copy of the display in a format useable by a printer or plotter Hi Res acquisition mode TDS 700A Models Only An acquisition mode in which the oscilloscope averages all samples taken during an acquisition interval to create a record point That average results in a higher resolution lower bandwidth wave form That mode only works with real time non interpolated sampling TDS 684A TDS 744A amp TDS 784A User Manual Glossary TU High The value used as 100 in automated measurements whenever high ref mid ref and low ref values are needed as in fall time and rise time measure ments May be calculated using either the min max
193. ger points on it Though the waveform is repetitive a simple trigger might get you a series of patterns on the screen instead of the same pattern each time A digital pulse train is a good example of a complex waveform See Fig ure 3 31 Each pulse looks like any other so many possible trigger points exist TDS 684A TDS 744A amp TDS 784A User Manual 3 51 Triggering on Waveforms 3 52 Not all of these will result in the same display The holdoff period allows the oscilloscope to trigger on the correct edge resulting in a stable display Acquisition Acquisition Interval Interval Trigger Level V E n E enka 61 Se Trigger P oints N g yY Holdoff Holdoff Holdoff Triggers are not recognized during holdoff time Figure 3 31 Trigger Holdoff Time Ensures Valid Triggering Holdoff is settable from 250 ns minimum holdoff available to 12 seconds maximum holdoff available To see how to set holdoff see To Set Mode amp Holdoff on page 3 59 You can also set a default holdoff The default hold is the general purpose holdoff for most triggering signals and varies with the horizontal scale It is equal to 5 divisions times the current time division settings Trigger Coupling Trigger coupling determines what part of the signal is passed to the trigger circuit All trigger types except edge triggering use only DC coupling edge triggering can use all available coupling types AC DC Low Frequency R
194. gering system to start an acquisition High frequency rejection attenuates signals above 30 kHz TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms Nt LF Rej removes the low frequency portion of the triggering signal Low frequency rejection attenuates signals below 80 kHz Noise Rej provides lower sensitivity Noise Rej requires additional signal amplitude for stable triggering reducing the chance of falsely triggering on noise NOTE When you select Line as the trigger source the oscilloscope uses AC coupling to couple a sample of the AC line voltage to the trigger circuits Although trigger coupling can be set to other than AC when in Line the oscilloscope ignores the setting until another source one of Chl through Ch4 is selected In similar fashion when you select DC Aux Rear Panel as the trigger source the oscilloscope uses DC coupling to couple an auxiliary signal to the trigger circuits Although trigger coupling can be set to other than DC when in DC Aux the oscilloscope ignores the setting until one of Ch1 through Ch4 is selected To Set Mode amp Holdoff You can change the holdoff time and select the trigger mode using this menu item See Trigger Modes and Trigger Holdoff beginning on page 3 51 for a description of these features To set mode and holdoff do the following steps 1 Press the TRIGGER MENU Mode amp Holdoff main gt Auto or Normal side The modes operate as f
195. gger Instruction Manual Tektronix part number 070 8748 xx describes use of the video trigger option for TDS oscilloscopes equipped with that option only m The TDS 684A TDS 744A amp TDS 784A Service Manual Tektronix part number 070 8992 xx provides information for maintaining and servicing the oscilloscope to the module level TDS 684A TDS 744A amp TDS 784A User Manual xiii Preface Conventions Default Model xiv In this manual you will find various procedures which contain steps of instructions for you to perform To keep those instructions clear and consistent this manual uses the following conventions m In procedures names of front panel controls and menu labels appear in boldface print m Names also appear in the same case initial capitals or all uppercase in the manual as is used on the oscilloscope front panel and menus Front panel names are all upper case letters for example VERTICAL MENU and CH 1 m Instruction steps are numbered The number is omitted if there is only one step m When steps require that you make a sequence of selections using front panel controls and menu buttons an arrow gt marks each transition between a front panel button and a menu or between menus Also whether a name is a main menu or side menu item is clearly indicated Press VERTICAL MENU gt Coupling main gt DC side gt Bandwidth main gt 250 MHz side Using the convention just described results i
196. gger When main gt Delta Time side 5 Use the general purpose knob or keypad to set the delta time value for slew rate NOTE The menu item Slew Rate in the side menu is not a button label rather it is a readout of the slew rate setting This readout varies as you vary the Delta Time setting this side menu and as you vary either of the threshold settings from the Thresholds menu You adjust those parameters to adjust slew rate you can t adjust slew rate directly Set to Trig When The oscilloscope compares the pulse edge of the trigger source against the slew rate setting read out in the Trigger When menu To select TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms whether to trigger on edges with slew rates faster than or slower than that indicated in readout do the following step Press TRIGGER MENU gt Type main gt Pulse pop up gt Class main gt Slew Rate pop up gt Trigger When main gt Trigger if Faster Than or Trigger if Slower Than side See Figure 3 46 NOTE If you select Trigger if Faster Than and the oscilloscope does not trigger it may be because the pulse edge is too fast rather than too slow To check the edge speed switch to edge triggering Then trigger on the pulse edge and determine the time the edge takes to travel between the levels set in the slew rate Thresholds menu The oscilloscope cannot slew rate trigger on pulse edges that traverse between
197. gger menu 3 67 3 68 Status Determining setup 3 133 STATUS button 3 133 Status menu 3 133 3 136 Display 3 133 Firmware version 3 133 TO 3 133 System 3 133 Trigger 3 133 Waveforms 3 133 Stop After Limit Test Condition Met Acquire menu 3 140 Stop After Acquire menu 3 25 3 141 Style Display menu 3 28 Switch principal power 1 5 2 5 System Status menu 3 133 System Utility menu 3 122 T Talk Listen Address Utility menu 3 131 TDS 700A xiv Tek Secure 3 113 Glossary 10 Tek Secure Erase Memory Utility menu 3 113 Temperature compensation 3 102 Temperature Color menu 3 34 Template Source Acquire menu 3 138 Text Grat Display menu 3 29 Thinkjet 3 121 Thinkjet Hardcopy menu 3 122 Thresholds Main Trigger menu 3 75 3 78 TIFF 3 121 TIFF Hardcopy menu 3 122 Time base Glossary 10 Time Base Horizontal menu 3 83 Time Units Cursor menu 3 101 Time to voltage converter E 5 Tracking Cursor menu 3 100 Trigger 3 49 3 86 Glossary 10 AC Line Voltage 3 50 Auxiliary 3 50 Coupling 3 52 3 86 Delay 3 53 TDS 684A TDS 744A amp TDS 784A User Manual Delayed 3 8 1 3 86 Edge 3 50 3 57 Glossary 3 Glitch 3 71 Glossary 4 Holdoff 3 51 Level 3 53 Glossary 10 Logic 3 50 3 60 3 86 Mode 3 51 Pattern 3 61 3 64 3 86 Position 3 14 3 48 3 52 Pulse 3 50 3 70 Readout 3 55 3 56 Runt 3 71 3 72 Glossary 9 Setup Hold 3 61 3
198. glitches of either polarity A runt trigger occurs when the trigger source detects a short pulse that crosses one threshold but fails to cross a second threshold before recrossing the first You can set the oscilloscope to detect positive or negative runt pulses A width trigger occurs when the trigger source detects a pulse that is inside or optionally outside some specified time range defined by the upper limit and lower limit The oscilloscope can trigger on positive or negative width pulses A slew rate trigger occurs when the trigger source detects a pulse edge that traverses slews between two amplitude levels at a rate faster than or slower than you specify The oscilloscope can trigger on positive or negative slew rates You can also think of slew rate triggering as triggering based on the slope change in voltage change in time of a pulse edge Figure 3 43 shows the pulse trigger readout Table 3 8 on page 3 71 describes the choices for pulse triggers Trigger Class Runt foe ine Livin Ked MB Tema tf 2 Set to ECL J Glitch TR am SMMC ido Runt chi f width f Slew Rate i 3 i J Source Polarity i oge class HH hresholds amp lt Runt gt chi Positive occurs Threshoy Holdoff MIPIC IC G C O Figure 3 43 Pulse Trigger Readouts Table 3 8 Pulse Trigger Definitions Name
199. he knob scales only the selected waveform When you select a channel the horizontal POSITION knob positions all channel reference and math waveforms displayed at the same time when Horizontal Lock is set to Lock in the Zoom menu See Zoom a Waveform on page 3 38 To select the waveform record length and the trigger position use the Horizontal menu You can also use this menu to change the horizontal position or scale instead of using the horizontal knobs You can select the delayed time base see Delayed Triggering on page 3 80 or choose the frames on the waveform that you want to see see Using FastFrame on page 3 46 Trigger Position The trigger point marks time zero in a waveform record All record points before the trigger event make up the pretrigger portion of the waveform record Every record point after the trigger event is part of the TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms posttrigger portion All timing measurements in the waveform record are made relative to the trigger event To define the trigger point position Press HORIZONTAL MENU gt Trigger Position main gt Set to 10 Set to 50 or Set to 90 side or use the general purpose knob or the keypad to change the value Record Length The number of points that make up the waveform record is defined by the record length To set the waveform record length 1 Press HORIZONTAL MENU gt Record Length main Selec
200. idth you set Enter the width using the general purpose knob or keypad Tek Run 5 00MS s Sample Runt High Threshold 2 00 V Pulse Runt Thresholds z PEPP feat had Selected trigger bar at upper threshold Unselected trigger bar at lower EA l i i kaiek i i oo Runt Pulse Crosses First Threshold Swed Laie eae lll O fel od Set to ECL Only Recrosses First Threshold a Level and Triggers Acquisition 3 a 10 0s Runt cht Width LOD IDG Slew Rate g een Po rigger ELF _ hype Class pou Polarity When hresholds amp lt Pulse gt lt Runt Occurs Holdoff 119 1 1 1 Figure 3 45 Main Trigger Menu Runt Class Set the Thresholds To set the two threshold levels used in detecting a runt pulse 1 Press TRIGGER MENU gt Type main gt Pulse pop up gt Class main gt Runt pop up gt Thresholds main 2 Use the general purpose knob or keypad to set the values for the high and low thresholds TDS 684A TDS 744A amp TDS 784A User Manual 3 75 Triggering on Waveforms 3 76 Trigger Based on Pulse Width Hint To use the Trigger Bar feature to set the threshold levels on the pulse train press DISPLAY Readout Options main gt Trigger Bar Style side until Long appears in that menu item Note the position of the trigger indicator in F
201. igure 3 45 on page 3 75 Trigger ing occurs at the point the pulse returns over the first lower threshold going negative without crossing the second threshold level upper The polarity selected in the Polarity side menu determines the order that the threshold must be crossed for a runt trigger to occur Positive requires that the Jower threshold must be first crossed going positive then recrossed going negative without the upper threshold being crossed at all Negative requires that the upper threshold must be first crossed going negative then recrossed going positive without the lower threshold being crossed at all Either requires only that either one of the thresholds must be first crossed going in either direction then recrossed going in the opposite direction without the other threshold being crossed at all For all three polarity settings triggering occurs at the point the runt pulse recrosses its first threshold Set the Mode and Holdoff Mode and holdoff can be set for all standard trigger types and classes To set mode and holdoff refer to Set Mode amp Holdoff on page 3 59 To learn more about trigger mode and holdoff see Trigger Modes and Trigger Holdoff on page 3 51 When you select the pulse class Width the oscilloscope will trigger on a pulse narrower or wider than some specified range of time defined by the upper limit and lower limit To set up for width triggering do the following proce dures Select Wi
202. illoscope has recognized a valid main trigger and is waiting for a delayed trigger When the oscilloscope recognizes a delayed trigger it will fill in the posttrigger portion of the delayed waveform m When ARM TRIG D and READY are all off the digitizer is stopped m When ARM TRIG D and READY are all lighted TDS 700A models only FastFrame or InstaVu modes are in effect No trigger status monitoring is taking place Trigger Readout To quickly determine the settings of some key trigger parame ters check the Trigger readout at the bottom of the display See Figure 3 34 The readouts differ for edge logic and pulse triggers TDS 684A TDS 744A amp TDS 784A User Manual 3 55 Triggering on Waveforms Trigger Position Relative to the Display and Waveform Record Trigger Point Indicator Indicating the Trigger Position on the Waveform Record Trigger Bar Indicating the Trigger Level on the Waveform Record 3 56 Main Trigger Main Trigger Main Time Base Time Div cource Ch1 Slope Rising Edge Main Trigger Level Main Time Base Dooa Figure 3 34 Example Trigger Readouts Edge Trigger Selected Record View To determine where the trigger point is located in the waveform record and with respect to the display check the record view at the top of the display See Figure 3 35 Tek Run 1 00GS 5 ia D Select Measu
203. ion message is displayed continue with step 15 otherwise continue with step 12 12 If the Compensation Error message is displayed continue with step 13 otherwise continue with step 18 TDS 684A TDS 744A amp TDS 784A User Manual Measuring Waveforms 13 Press SHIFT UTILITY gt System main gt Diag Err pop up gt Error Log main If there are too many error messages to be seen on screen rotate the general purpose knob clockwise to scroll to the last message 14 Note the compensation error amount Skip to step 19 15 Disconnect the probe from any signal you may have connected it to Leave the probe installed on its channel 16 Press OK Compensate Offset side D 17 Wait for offset compensation to complete one to three minutes When offset compensation completes the following occurs m The clock icon will disappear m If offset compensation did not complete successfully you may get the message Compensation Error This error implies that the probe offset scale 10 error and or offset 50 mV is too great to be compensated You can substitute another probe and continue Have your probe checked by service personnel You can also check the error log by doing steps 13 through 14 18 After the clock icon is removed verify the word Initialized changed to Pass under Cal Probe in the main menu See Figure 3 63 19 If desired repeat this procedure beginning at step 1 to compensate for other probe chann
204. isplayed at any one time Pressing the button next to the more menu item brings up the other measurement selections Press Frequency side If the Frequency menu item is not visible press more side repeatedly until the Frequency item appears Then press Frequency side Observe that the frequency measurement appears within the right side of the graticule area The measurement readout includes the notation Ch1 meaning that the measurement is taken on the channel waveform To take a TDS 684A TDS 744A amp TDS 784A User Manual 2 19 Tutorial measurement on another channel select that channel and then select the measurement Tek Run 100kKS 5 Sample Select Measurement Frequency Positi widt Negative width lot see rarte MEFE Remove Gating t Reference Measrmnt Setup Snapshot arms Vieasrmnat OFF Histogram Levels 200mv 3 M S00ps chi 7 248mv more I 1C 91 9191 Figure 2 14 Measure Main Menu and Select Measurement Side Menu 7 Press Positive Width side gt more side gt Rise Time side gt eo Positive Duty Cycle side All four measurements are displayed Right now they cover a part of the graticule area including the displayed waveforms 8 To move the measurement readouts outside the graticule a
205. itors the slew rate of the positive going edges of pulses The edge must first cross the lower threshold and then cross the upper threshold Negative monitors the slew rate of the negative going edges of pulses The edge must first cross the upper threshold and then cross the lower threshold Either monitors positive and negative going edges of pulses The edge may first cross either threshold and then cross the other Set the Slew Rate The threshold levels and the delta time setting determine the slew rate setting To set these parameters 1 Press TRIGGER MENU gt Type main gt Pulse pop up gt Class main gt Slew Rate pop up gt Thresholds main 2 Press Set to TTL or Set to ECL side to set the upper and lower thresholds to levels appropriate for those to logic families OR 3 Press the upper threshold button and in turn lower threshold button side Use the general purpose knob or keypad to set the values for the high and low thresholds Hint To use the Trigger Bar feature to set the threshold levels on the pulse edge press DISPLAY Readout Options main gt Trigger Bar Style side until Long appears in that menu item The threshold settings determine the voltage component of slew rate Volts Se cond To finish specifying the slew rate set the time component by doing the following steps 4 Press TRIGGER MENU gt Type main gt Pulse pop up gt Class main gt Slew Rate pop up gt Tri
206. its TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms Checking the To determine the acquisition sampling rate the acquisition state running or Acquisition Readout stopped and the acquisition mode check the Acquisition readout at the top of the display See Figure 3 14 The state Run shows the sample rate and acquisition mode The state Stop shows the number of acquisitions acquired since the last stop or major change Acquisition R eadout R n onesies Sample Acquisition Mode Sample magn Envelope 10 Average 16 Zoomy C M 500s Chif 248mV DUER stop After Limit Test Limit z Create Limit Test Rates a S button Setup Sources Template MIP IC IOIC Figure 3 14 Acquisition Menu and Readout Selecting an The oscilloscope provides several modes see The Acquisition Modes on Acquisition Mode page 3 20 for acquiring and converting analog data into digital form To choose how the oscilloscope will create points in the waveform record 1 Press SHIFT ACQUIRE MENU gt Mode main See Figure 3 14 2 TDS 684A Press Sample Envelope or Average side or TDS 700A Models Press Sample Peak Detect Hi Res Envelope or Average side InstaVu mode must be off to use Hi Res Envelope or Average modes 3 Ifyou sel
207. itude as their frequency increases m Sample the source signal at rates that are at least 2X that of the highest frequency component having significant amplitude m Filter the input to bandwidth limit it to frequencies below that of the Nyquist frequency m Recognize and ignore the aliased frequencies If you think you have aliased frequencies in your FFT select the source channel and adjust the horizontal scale to increase the sample rate Since you increase the Nyquist frequency as you increase the sample rate the alias signals should appear at their proper frequency TDS 684A TDS 744A amp TDS 784A User Manual 3 155 Using Features for Advanced Applications Considerations for Phase 3 156 Displays Nyquist Frequency Point Amplitude allied sei eae Frequency Aliased Frequencies Actual Frequencies Ge Figure 3 92 How Aliased Frequencies Appear in an FFT When you set up an FFT math waveform to display the phase angle of the frequencies contained in a waveform you should take into account the reference point the phase is measured against You may also need to use phase suppression to reduce noise in your FFTs Establish a Zero Phase Reference Point The phase of each frequency is measured with respect to the zero phase reference point The zero reference point is the point at the center of the FFT math waveform but corresponds to various points on the source time domain record See Figure 3 90 on p
208. ive probe with this procedure you must first compensate the low frequency response of the probe First do steps 1 and 2 below and then compensate the probe by following the instructions that came with your probe Or see To Compensate Passive Probes on page 3 3 Then continue with step 3 of this procedure 1 Install the probe on the input channel on which it is to be used 2 Power on the digitizing oscilloscope and allow a 20 minute warm up before doing this procedure 3 Press SHIFT UTILITY gt System main gt Cal pop up 4 Look at the status label under Signal Path in the main menu If the status does not read Pass perform a signal path compensation Signal Path Compensation page 3 102 and then continue with this procedure 5 Press the front panel button corresponding to the input channel on which you installed the probe 6 Press VERTICAL MENU gt Cal Probe main STOP Your oscilloscope will detect the type of probe you have installed and display screen messages and menu choices for compensation of probe gain offset or both See Figure 3 63 The following steps will have you run probe gain offset or both depending on the probe the oscilloscope detects 7 Ifthe message on screen is Probe Offset Compensation rather than Probe Gain Compensation skip to step 15 8 Connect the probe tip to PROBE COMPENSATION SIGNAL connect the probe ground lead to PROBE COMPENSATION GND 9 Press OK Compensate Gain
209. ization Defaults Cont Control Changed by Factory Init to Display color collision contrast Off Display color map math colors Color Math Display color map reference colors Color Ref Display color palette Normal Display color palette colors The colors of each palette are reset to factory hue saturation and lightness HLS values Display color persistence palette Temperature Display format YT Display graticule type Full Display intensity text 100 Display intensity waveform 100 Display interpolation filter Sin x x Display Mode TDS 700A models only Normal InstaVu acquisition off Display style Vectors Display trigger bar style Short Display trigger T On Display variable persistence 500 ms Edge trigger coupling DC Edge trigger level 0 0V Edge trigger slope Rising Edge trigger source Channel 1 GPIB parameters No change Hardcopy Format Unchanged Layout Unchanged Palette Unchanged Port Unchanged Horizontal delay trigger position 50 Horizontal delay time division 50 us Horizontal FastFrame TDS 700A models only Off Horizontal FastFrame frame count 2 TDS 700A models only Horizontal FastF rame frame length 500 TDS 700A models only Horizontal fit to screen Off D 2 TDS 684A TDS 744A amp TDS 784A User Manual Appendix D Factory Initialization Settings Table D 1 Factory Initialization Defaults Cont Control
210. k When you use setup hold triggering you define m The channel containing the logic input the data source and the channel containing the clock the clock source m The direction of the clock edge to use m The clocking level and data level that the oscilloscope uses to determine if a clock or data transition has occurred m The setup and hold times that together define a time range relative to the clock Pattern and State Classes Pattern and state triggers apply boolean logic functions to the logic inputs Table 3 7 defines these four logic functions For pattern triggering the oscilloscope waits until the end of trigger holdoff and then samples the inputs from all the channels The oscilloscope then triggers if the conditions defined in Table 3 7 are met Goes TRUE or Goes FALSE must be set in the Trigger When menu The other settings in that menu are described in To Define a Time Qualified Pattern Trigger on page 3 66 TDS 684A TDS 744A amp TDS 784A User Manual 3 61 Triggering on Waveforms 3 62 Setup and Hold Class For state triggering the oscilloscope waits until the end of trigger holdoff and then waits until the edge of channel 4 transitions in the specified direction At that point the oscilloscope samples the inputs from the other channels and triggers if the conditions defined in Table 3 7 are met Table 3 7 Pattern and State Logic AND Clocked AND If allthe preconditions selected for the 3 logic input
211. lected cursor to the bottom or to any amplitude level you choose 6 Read the integrated voltage over time between the cursors in volt seconds from the A readout Read the integrated voltage over time between the selected cursor and the reference indicator of the math waveform from the readout See Figure 3 98 TDS 684A TDS 744A amp TDS 784A User Manual 3 167 Using Features for Advanced Applications 3 168 Integral Math Waveform Source Waveform Tek Run 5 00MS s Sample Cursor Function M 10 045 Chis 520m v MIGIC IOC O Figure 3 98 H Bars Cursors Measure an Integral Math Waveform 7 Press Function main gt V Bars side Use the general purpose knob to align one of the two vertical cursors to a point of interest along the horizon tal axis of the waveform 8 Press SELECT to select the alternate cursor 9 Align the alternate cursor to another point of interest on the math waveform 10 Read the time difference between the cursors from the A readout Read the time difference between the selected cursor and the trigger point for the source waveform from the readout 11 Press Function main gt Paired side 12 Use the technique just outlined to place the long vertical bar of each paired cursor to the points along the horizontal axis you are interested in 13 Read the following
212. less than or equal to the Upper Limit Set the Level Press TRIGGER MENU gt Type main gt Pulse pop up gt Class main gt Width pop up gt Level main gt Level Set to TTL Set to ECL or Set to 50 side Set the Mode and Holdoff Mode and holdoff can be set for all standard trigger types and classes To set mode and holdoff refer to Set Mode amp Holdoff on page 3 59 To learn more about trigger mode and holdoff see Trigger Modes and Trigger Holdoff on page 3 51 To Trigger Based When you select the pulse class Slew Rate the oscilloscope will trigger on a on Slew Rate pulse edge that traverses between an upper and lower threshold faster or slower than a slew rate you specify To set up for slew rate triggering do the following procedures Select Slew Rate Triggering Press TRIGGER MENU gt Type main gt Pulse pop up Class main gt Slew Rate pop up See Figure 3 46 on page 3 79 Select the Source Press TRIGGER MENU Type main gt Pulse pop up Source main Ch1 Ch2 Ch3 or Ch4 side The source selected becomes the trigger source for all four trigger classes Select Polarity To specify the direction of the pulse edge press TRIGGER MENU gt Type main gt Pulse pop up gt Class main gt Slew Rate pop up gt Polarity main gt Positive Negative or Either side TDS 684A TDS 744A amp TDS 784A User Manual 3 77 Triggering on Waveforms 3 78 Positive mon
213. lloscopes Tektronix also offers a variety of BNC cabling and connectors to couple a variety of signal sources to its input channels See your Tektronix Sales representative for the specific items offered for signal coupling To Compensate When using a passive probe with any product compensate it to ensure maximum Passive Probes distortion free input to the oscilloscope and to avoid high frequency amplitude errors see Figure 3 1 To compensate your probe do the following steps 1 Connect the probe to the probe compensation signal on the front panel 2 Press AUTOSET 3 Press VERTICAL MENU gt Bandwidth main gt 20 MHz side TDS 684A TDS 744A amp TDS 784A User Manual 3 3 Acquiring and Displaying Waveforms 3 4 Probe Compensated Correctly Probe Overcompensated Probe Undercompensated Figure 3 1 How Probe Compensation Affects Signals 4 If you need to change the input impedance press Coupling main Then toggle the side menu selection Q to get the correct impedance 5 TDS 700A models only Press SHIFT ACQUIRE MENU Mode main gt Hi Res side 6 TDS 684A only Press SHIFT ACQUIRE MENU gt Mode main gt Average side Use the keypad to set Averages to 5 7 Adjust the probe until you see a square wave with a perfectly flat top on the display Figure 3 2 shows where the adjustment is located Figure 3 2 P6139A Probe Adjustment TDS 684A TDS 744A amp TDS 784A User
214. lp screens for shifted menus The shifted menus are the Acquire menu Application menu Hardcopy menu Delayed Trigger menu Status menu and Utility menu With Help off press SHIFT lighted when on before turning the general purpose horizontal position or vertical position knobs when you want increased knob response Less knob rotation will produce greater changes in settings With Help off press SHIFT after pressing any menu button that toggles through multiple settings such as those for pop up menus Pressing SHIFT reverses the direction in which the pop up menu or button label toggles through the menu or parameter settings OIIO i soomv M 20 0ns Chi f 1191 9191 Figure 3 81 Initial Help Screen When you press that button the instrument changes mode to support on line help Press HELP again to return to regular operating mode Whenever the oscilloscope is in help mode pressing any button except HELP or SHIFT turning any knob or pressing any menu item displays help text on the screen that discusses that control The menu selections that were displayed when HELP was first pressed remain on the screen On line help is available for each menu selection displayed at the time the HELP button was first pressed If you are in help mode and want to see help on selections from menus not displayed you first exit help mode display the menu you wa
215. m For TDS 700A models only after the FFT is set up and displayed you can to turn on Hi Res mode to reduce the effect of noise in the signal Hi Res operates on both repetitive and nonrepetitive waveforms however it does affect the frequency response of the source waveform Peak Detect and Envelope Add Distortion Peak Detect TDS 700A models and Envelope mode can add significant distortion to the FFT results and are not recommended for use with FFTs Once you have your waveform displayed optimally you may magnify or reduce it vertically and horizontally to inspect any feature you desire Just be sure the FFT waveform is the selected waveform Press MORE then select the FFT waveform in the More main menu Then use the Vertical and Horizontal SCALE knobs to adjust the math waveform size If you wish to see the zoom factor 2X 5X etc you need to turn Zoom on press ZOOM gt On side The vertical and horizontal zoom factors appear on screen Whether Zoom is on or off you can press Reset Zoom Factors side to return the zoomed FFT waveform to no magnification Zoom always uses either sin x x or linear interpolation when expanding displayed waveforms To select the interpolation method press DISPLAY gt Setting main gt Display pop up gt Filter main gt Sin x x or Linear side If the source waveform record length is 500 points the FFT will use 2X Zoom to increase the 250 point FFT frequency domain record to
216. m to the display 1 If you are not continuing from the previous example follow the instructions on page 2 9 under the heading Setting Up for the Examples Press SETUP Recall Factory Setup main gt OK Confirm Factory Init side Press AUTOSET Press CH 2 The display shows a second waveform which represents the signal on channel 2 Since there is nothing connected to the CH 2 input connector this waveform is a flat line There are several other important things to observe m The channel readout on the display now shows the settings for both Ch1 and Ch2 m There are two channel indicators at the left edge of the graticule Right now they overlap TDS 684A TDS 744A amp TDS 784A User Manual Tutorial m The light above the CH 2 button is now on and the CH 1 light is off Because the knobs control only one channel at a time the vertical controls are now set to adjust channel 2 m The trigger readout still indicates that the trigger is detecting trigger events on Ch1 The trigger source is not changed simply by adding a channel You can change the trigger source by using the TRIGGER MENU button to display the trigger menu 5 Turn the vertical POSITION knob clockwise to move the channel 2 waveform up on the graticule You will notice that the channel reference indicator for channel 2 moves with the waveform 6 Press VERTICAL MENU gt Coupling main The VERTICAL MENU button displays a menu that gives y
217. measuring noisy signals because it allows the oscilloscope to ignore minor fluctuations in the signal MCross Calculations MCross1 MCross2 and MCross3 refer to the first second and third MidRef cross times respectively See Figure B 1 The polarity of the crossings does not matter for these variables but the crossings alternate in polarity that is MCross1 could be a positive or negative crossing but if MCross is a positive crossing MCross2 will be a negative crossing The oscilloscope calculates these values as follows 1 Find the first MidRefCrossing in the waveform record or the gated region This is MCross1 2 Continuing from MCross1 find the next MidRefCrossing in the waveform record or the gated region of the opposite polarity of MCross1 This is MCross2 3 Continuing from MCross2 find the next MidRefCrossing in the waveform record or the gated region of the same polarity as MCross1 This is MCross3 TDS 684A TDS 744A amp TDS 784A User Manual B 3 Appendix B Algorithms MidR ef Hysteresis x Amplitude MidR ef MidR ef Hysteresis x Amplitude MCross1Polarity is the polarity of first crossing no default It can be rising or falling StartCycle is the starting time for cycle measurements It is a floating point number with values between 0 0 and RecordLength 1 0 inclusive StartCycle MCross1 EndCycle is the ending time for cycle measurements It is a flo
218. ment Time taken for the falling edge of the first pulse in the waveform or gated region to fall from a High Ref value default 90 to a Low Ref value default 10 of its final value Frequency frf High Timing measurement for the first cycle in the waveform or gated region The reciprocal of the period Measured in Hertz Hz where 1 Hz 1 cycle per second The value used as 100 whenever High Ref Mid Ref and Low Ref values are needed as in fall time and rise time measurements Calculated using either the min max or the histogram method The min max method uses the maximum value found The histogram method uses the most common value found above the mid point Measured over the entire waveform or gated region 3 88 TDS 684A TDS 744A amp TDS 784A User Manual Measuring Waveforms Table 3 9 Measurement Definitions Cont Name Definition ne Low The value used as 0 whenever High Ref Mid Ref and Low Ref values are needed as in fall eS time and rise time measurements May be calculated using either the min max or the histogram method With the min max method it is the minimum value found With the histogram method it refers to the most common value found below the midpoint Measured over the entire waveform or gated region T Maximum Voltage measurement The maximum amplitude Typically the most positive peak volt
219. ment will result See the User manual for the probe for more information Instead use a passive probe such as P6139A passive probe that allows higher voltage measurements The P6139A probe is for measurements up to 500 volts CAUTION Using the P6245 Active Probe to measure signals greater than 40 volts may damage the probe Be sure to choose the proper input coupling and impedance for the probe or other cabling you use to couple signals to your oscilloscope You should read Input Impedance Considerations on page 3 5 for information needed to ensure proper coupling of your input signals TDS 684A TDS 744A amp TDS 784A User Manual 1 3 Start Up Putting into Service To learn how to install access the front panel power on do a self test and power off the oscilloscope do the following procedures Installation To properly install and power on the oscilloscope do the following steps 1 Be sure you have the appropriate operating environment Specifications for temperature relative humidity altitude vibrations and emissions are included in the TDS 684A TDS 744A amp TDS 784A Performance Verifica tion and Specifications manual Tektronix part number 070 8990 xx 2 Leave space for cooling Do this by verifying that the air intake and exhaust holes on the sides of the cabinet where the fan operates are free of any airflow obstructions Leave at least 5 1 cm 2 inches free on each side WARNING To avoid
220. mode uses a timer that starts after a trigger event occurs If another trigger event is not detected before the timer times out the oscilloscope forces a trigger anyway The length of time it waits for a trigger event depends on the time base setting Auto mode triggering is not available in InstaVu mode TDS 700A models only see Incompatible Modes on page 3 45 Be aware that auto mode when forcing triggers in the absence of valid triggering events does not sync the waveform on the display In other words successive acquisitions will not be triggered at the same point on the waveform therefore the waveform will appear to roll across the screen Of course if valid triggers occur the display will become stable on screen Since auto mode will force a trigger in the absence of one auto mode is useful in observing signals where you are only concerned with monitoring amplitude level Although the unsynced waveform may roll across the display it will not freeze as it would in normal trigger mode Monitoring of a power supply output is an example of such an application Trigger Holdoff When the oscilloscope recognizes a trigger event it disables the trigger system until acquisition is complete In addition the trigger system remains disabled during the holdoff period that follows each acquisition You can set holdoff time to help ensure a stable display For example the trigger signal can be a complex waveform with many possible trig
221. n gt Pulse pop up gt Class main gt Glitch pop up gt Glitch main gt Accept Glitch or Reject Glitch side TDS 684A TDS 744A amp TDS 784A User Manual 3 73 Triggering on Waveforms To Trigger on a Runt Pulse 3 74 If you choose Accept Glitch the oscilloscope will trigger only on pulses narrower than the width you specified If you select Reject Glitch it will trigger only on pulses wider than the specified width Set the Level To set the trigger level with the Level main menu or the front panel trigger LEVEL knob press TRIGGER MENU gt Type main gt Pulse pop up gt Level main gt Level Set to TTL Set to ECL or Set to 50 side m If you select Level you set the trigger level by entering a value with the general purpose knob or the keypad m If you select Set to TTL the oscilloscope sets the trigger level to the TTL switching threshold m If you select Set to ECL the oscilloscope sets the trigger level to the ECL switching threshold m If you select Set to 50 the oscilloscope searches for the point halfway between the peaks of the trigger source signal and sets the trigger level to that point To Set Mode and Holdoff Mode and holdoff can be set for all standard trigger types and classes To set mode and holdoff refer to To Set Mode amp Holdoff on page 3 59 To learn more about trigger mode and holdoff see the descriptions Trigger Modes and Trigger Holdoff on page 3 51
222. n exchange for the defective product In order to obtain service under this warranty Customer must notify Tektronix of the defect before the expiration of the warranty period and make suitable arrangements for the performance of service Customer shall be responsible for packaging and shipping the defective product to the service center designated by Tektronix with shipping charges prepaid Tektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the Tektronix service center is located Customer shall be responsible for paying all shipping charges duties taxes and any other charges for products returned to any other locations This warranty shall not apply to any defect failure or damage caused by improper use or improper or inadequate maintenance and care Tektronix shall not be obligated to furnish service under this warranty a to repair damage resulting from attempts by personnel other than Tektronix representatives to install repair or service the product b to repair damage resulting from improper use or connection to incompatible equipment or c to service a product that has been modified or integrated with other products when the effect of such modification or integration increases the time or difficulty of servicing the product THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THIS PRODUCT IN LIEU OF ANY OTHER WARRANTIES EXPRESSED OR IMPLIED TEKTRONIX AND ITS VENDORS
223. n instructions that are graphically intuitive and simplifies procedures For example the instruction just given replaces these five steps 1 Press the front panel button VERTICAL MENU Press the main menu button Coupling Press the side menu button DC PY ok Press the main menu button Bandwidth 5 Press the side menu button 250 MHz Sometimes you may have to make a selection from a pop up menu Press TRIGGER MENU gt Type main gt Edge pop up In this example you repeatedly press the main menu button Type until Edge is highlighted in the pop up menu This manual documents the TDS 684A TDS 744A and TDS 784A Digitizing Oscilloscopes However the TDS 684A display screen appears as the default screen wherever a display screen is illustrated in this manual Also this manual uses the name TDS 700A when providing information common to both the TDS 744A and TDS 784A model oscilloscopes TDS 684A TDS 744A amp TDS 784A User Manual E Product Description lololololo 2 0 0 0 0 0 0 0 f The Tektronix TDS Oscilloscope is a superb tool for acquiring displaying and Feature Digitizing rate maxi mum Analog bandwidth measuring waveforms Its performance addresses the needs of both benchtop lab and portable applications with the following feature
224. n seconds Phase A timing measurement between two waveforms of the amount one leads or lags the other in time Phase is expressed in degrees where 360 comprise one complete cycle of one of the waveforms Waveforms measured should be of the same frequency or one waveform should be a harmonic of the other TDS 684A TDS 744A amp TDS 784A User Manual Glossary 7 Glossary Glossary 8 Pixel A visible point on the display The oscilloscope display is 640 pixels wide by 480 pixels high Pop up Menu A sub menu of a main menu Pop up menus temporarily occupy part of the waveform display area and are used to present additional choices associated with the main menu selection You can cycle through the options in a pop up menu by repeatedly pressing the main menu button underneath the pop up Positive duty cycle A timing measurement of the ratio of the positive pulse width to the signal period expressed as a percentage Positive overshoot Amplitude voltage measurement Max High Amplitude IOC PositiveOvershoot Positive width A timing measurement of the distance time between two amplitude points rising edge MidRef default 50 and falling edge MidRef default 50 on a positive pulse Posttrigger The specified portion of the waveform record that contains data acquired after the trigger event Pretrigger The specified portion of the waveform record that contains data acquire
225. n that occurs when a oscilloscope digitizes at an effective sampling rate that is too slow to reproduce the input signal The waveform displayed on the oscilloscope may have a lower frequency than the actual input signal Amplitude The High waveform value less the Low waveform value AND A logic Boolean function in which the output is true when and only when all the inputs are true On the oscilloscope that is a trigger logic pattern and state function Area Measurement of the waveform area taken over the entire waveform or the gated region Expressed in volt seconds Area above ground is positive area below ground is negative TDS 684A TDS 744A amp TDS 784A User Manual Glossary 1 Glossary UU Glossary 2 Attenuation The degree the amplitude of a signal is reduced when it passes through an attenuating device such as a probe or attenuator That is the ratio of the input measure to the output measure For example a 10X probe will attenuate or reduce the input voltage of a signal by a factor of 10 Automatic trigger mode A trigger mode that causes the oscilloscope to automatically acquire if triggerable events are not detected within a specified time period Autoset A function of the oscilloscope that automatically produces a stable waveform of usable size Autoset sets up front panel controls based on the characteristics of the active waveform A successful autoset will set the vol
226. n the side menu that appears lt a The level control determines where on that edge the trigger point occurs See Figure 3 32 The oscilloscope lets you set the main trigger level with the trigger MAIN LEVEL knob Positive Going Edge Negative Going Edge Trigger level can be adjusted vertically k Pi YY Trigger slope can be positive or negative Figure 3 32 Slope and Level Controls Help Define the Trigger Delayed Trigger System The oscilloscope also has a delayed trigger system that provides an edge trigger no pulse or logic triggers When using the delayed time base you can also delay the acquisition of a waveform for a user specified time or a user specified number of delayed trigger events or both after a main trigger event See Delayed Triggering on page 3 80 to learn how to use delay Triggering from the Front Panel The trigger buttons and knob let you quickly adjust the trigger level or force a trigger See Figure 3 33 The trigger readout and status screen lets you quickly determine the state of the trigger system You use the following trigger controls and readouts for all trigger types except where noted TDS 684A TDS 744A amp TDS 784A User Manual 3 53 Triggering on Waveforms 3 54 Trigger Status Lights To set MAIN LEVEL To Set to 50 To Force a Trigger 4 TRIGGER MAIN LEVEL QO DELAYED TRIG TRIGGER MENU J SET LEVEL TO 50 J SINGLE TRIG FORCE TRIG J
227. nal period expressed as a percentage NegativeWidth is defined in Negative Width below If Period 0 or undefined then return an error NegativeWidth Period BUN NegativeDutyCycle Amplitude voltage measurement NegativeOvershoot Amplitude TDS 684A TDS 744A amp TDS 784A User Manual Appendix B Algorithms Note that this value should never be negative unless High or Low are set out of range Negative Width Timing measurement The distance time between MidRef default 50 amplitude points of a negative pulse If MCross1Polarity gt then NegativeWidth MCross2 MCross1 else NegativeWidth MCross3 MCross2 Peak to Peak Amplitude measurement The absolute difference between the maximum and minimum amplitude PeaktoPeak Max Min Period Timing measurement Time taken for one complete signal cycle The reciprocal of frequency Measured in seconds Period MCross3 MCross1 Phase Timing measurement The amount of phase shift expressed in degrees of the target waveform cycle between the MidRef crossings of two different wave flr forms Waveforms measured should be of the same frequency or one waveform should be a harmonic of the other Phase is a dual waveform measurement that is it is measured from a target waveform to a reference waveform To get a specific phase measurement you must specify the target and reference sources Phase is
228. nce Zo probe Provides 100X when ordered with Option 25 m P6139A 10X 500 MHz Passive probe m P6009 Passive high voltage probe 100X 1500 VDC Peak AC m P6015A Passive high voltage probe 1000X 20 kVDC Peak AC 40 kV peak for less than 100 ms m P6217 Active high speed digital voltage probe FET DC to 4 GHz DC offset 50 Q input Use with 1103 TekProbe Power Supply for offset control m P6204 Active high speed digital voltage probe FET DC to 1 GHz DC offset 50 Q input Use with 1103 TekProbe Power Supply for offset control m P6563AS Passive SMD probe 20X 500 MHz m P6046 Active differential probe 1X 10X DC to 100 MHz 50 Q input TDS 684A TDS 744A amp TDS 784A User Manual Appendix A Options and Accessories m AM 503S DC AC Current probe system AC DC Uses A6302 Current Probe m AM 503S Option 03 DC AC Current probe system AC DC Uses A6303 Current Probe m P6021 AC Current probe 120 Hz to 60 MHz m P6022 AC Current probe 935 kHz to 120 MHz m CT 1 Current probe designed for permanent or semi permanent in circuit installation 25 kHz to 1 GHz 50 Q input m CT 2 Current probe designed for permanent or semi permanent in circuit installation 1 2 kHz to 200 MHz 50 Q input CT 4 Current Transformer for use with the AM 503S A6302 and P6021 Peak pulse 1 kA 0 5 Hz to 20 MHz with AM 503S A6302 m P6701A Opto Electronic Converter 500 to 950 nm DC to 850 MHz 1 V mW
229. ncies Blackman Harris Best window for measuring the amplitude of frequencies but worst at resolving frequencies The topic Selecting a Window on page 3 158 provides in depth information on choosing the right window for your application If you did not select Phase deg or Phase rad in step 7 skip to step 12 Phase suppression is only used to reduce noise in phase FFTs If you need to reduce the effect of noise in your phase FFT press Suppress phase at amplitudes lt side Use the general purpose knob to adjust the phase suppression level FFT magnitudes below this level will have their phase set to zero The topic Adjust Phase Suppression on page 3 157 provides additional information on phase suppression Press OK Create Math Wfm side to display the FFT of the waveform you input in step 1 See Figure 3 88 Tek Run 50 0MS s Sample Oloo thi a0 va ps Chi A s00mv 29 Mar 1994 DME 20 0dE 2 50MHz 12 08 57 110 10 1 1 1 Figure 3 88 FFT Math Waveform in Math1 3 148 TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications To Take Cursor Once you have displayed an FFT math waveform use cursors to measure its Measurements of an FFT frequency amplitude or phase angle 1 Be sure MORE is selected in the channel selection buttons and that the FFT math waveform is selected in th
230. nds the oscilloscope monitors the data and clock sources When a clock edge occurs the oscilloscope checks the data stream it is processing from the data source for transitions occurring within the setup hold violation zone If any occur the oscilloscope triggers with the trigger point located at the clock edge Positive settings for both setup and hold times the most common application locate the setup hold violation zone so it spans the clocking edge See the top waveform in Figure 3 38 The oscilloscope detects and triggers on data that TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms does not become stable long enough before the clock setup time violation or that does not stay stable long enough after the clock hold time violation Setup Hold Ts Setup Time lt Violation gt Ty Hold Time Zone Setup Hold Violation Zone Ts Ty ae Ts Ty mustbe 2 ns lt e gt Clock Level Clock Signal Setup Hold lt Violation gt T Zone e Ty o m Clock Level Clock Signal Setup Hold lt Violation gt Zone T IH s Eea lt Clock Level Clock Signal Positive Tc Negative T4 Negative Ts Positive Ty Figure 3 38 Violation Zones for Setup Hold Triggering Negative settings for setup or hold times skew the setup hold violation zone to locate it before or after the clocking edge See the bottom and center wave
231. ned Yes Poweron Cannot detect differ Display Re use Probe Cal d Probe Pass ent probe Calibration Data menu Different probe Initialized Different probe Initialized Yes Disconnect Probe Initialized Initialized Yes Connect Probe Can not detect differ Display Re use Probe Cal d Probe Pass ent probe Calibration Data menu Different probe Initialized Different probe Initialized 1 Refers to a channel input that was successfully compensated at the time Probe Cal was last executed for the input channel 2 Ifo probe is connected the probe status in the vertical main menu is always initialized 3 A probe with a simple interface is a probe that can convey very limited information to the oscilloscope Most passive probes such as the P6139A have simple interfaces 4 Aprobe with a TEKPROBE interface is a probe that can convey additional information For instance it might automatical ly set the oscilloscope input channel impedance to match the probe send the oscilloscope a unique probe identification number and so on Some optical probes and most active probes such as the P6205 have TEKPROBE interfaces TDS 684A TDS 744A amp TDS 784A User Manual 3 109 Measuring Waveforms 3 110 TDS 684A TDS 744A amp TDS 784A User Manual a ery Saving Waveforms and Setups The TDS Oscilloscope can save and recall the waveforms you measure and the setups you use to measure them It can also output or save a copy of its display screen
232. nt information on and press HELP again to re enter help mode TDS 684A TDS 744A amp TDS 784A User Manual 3 135 Determining Status and Accessing Help 3 136 TDS 684A TDS 744A amp TDS 784A User Manual ee ey Using Features for Advanced Applications The TDS Oscilloscope provides powerful features for testing and digitally proces sing the waveforms you acquire This section describes how to use the following features Limit Testing for testing the waveforms you acquire against a template you create on this page Waveform Math for inverting adding subtracting and multiplying of waveforms see page 3 142 Fast Fourier Transforms for displaying the frequency content of waveforms see page 3 144 Waveform Differentiation for displaying the derivative of a waveform see page 3 161 Waveform Integration for displaying the integral of a waveform see page 3 165 NOTE If InstaVu mode is on the features listed above are not available press InstaVu on the front panel to toggle InstaVu mode off Limit Testing The TDS Oscilloscope provides limit testing which can automatically compare each incoming or math waveform against a template waveform You set an envelope of limits around a waveform and the oscilloscope finds waveforms that fall outside those limits See Figure 3 82 When it finds such a waveform the oscilloscope can generate a hardcopy ring a bell and stop and wait for your input
233. o run an SPC if the temperature has changed more than 5 C since the last SPC was performed NOTE When making measurements at volts division settings less than or equal to 5 mV you should run SPC at least once per week Failure to do so may result in the oscilloscope not meeting warranted performance levels at those volts div settings Warranted characteristics are listed in the Performance Verification and Specifications manual To run an SPC do the following steps 1 Power on the digitizing oscilloscope and allow a 20 minute warm up before doing this procedure 2 Disconnect any input signals you may have connected from all four input channels STOP When doing steps 3 and 4 do not turn off the oscilloscope until signal path compensation completes If you interrupt or lose power to the instrument while signal path compensation is running a message is logged in the oscillo scope error log If such a case occurs rerun signal path compensation 3 Press SHIFT UTILITY System main gt Cal pop up gt Signal Path main gt OK Compensate Signal Paths side D 4 Wait for signal path compensation to complete up to 15 minutes While it progresses a clock icon shown at left is displayed on screen When compensation completes the status message will be updated to Pass or Fail in the main menu 5 Verify the word Pass appears under Signal Path in the main menu See Figure 3 62 TDS 684A TDS 74
234. of the oscilloscope The connector has a D type shell and conforms to IEEE Std 488 1 1987 You can stack GPIB connectors on top of each other See Figure 3 76 Figure 3 76 Stacking GPIB Connectors To set up remote communications be sure your setup will meet GPIB protocol and interface requirements just described Then do the following procedures Connect the Oscilloscope to the GPIB To connect the oscilloscope plug an IEEE Std 488 2 1987 GPIB cable into the GPIB connector on the oscilloscope rear panel and into the GPIB port on your controller See Figure 3 77 TDS 684A TDS 744A amp TDS 784A User Manual Saving Waveforms and Setups Controller Digitizing Oscilloscope Rear P anel ea Ea Ci o 0 OCIO a GPIB Connector Figure 3 77 Connecting the Oscilloscope to a Controller Select GPIB Port To select the GPIB port press SHIFT gt UTILITY gt System main gt I O pop up gt Port main gt GPIB pop up Configure the GPIB Port You must set two important GPIB parameters mode and address To set those parameters Press SHIFT UTILITY gt System main gt I O pop up gt Port main gt GPIB pop up gt Configure main gt Talk Listen Address Hardcopy Talk Only or Off Bus side See Figure 3 78 Talk Listen A
235. off If the oscilloscope setup is not as you expect it when you turn InstaVu off it may be because it quit ignoring these InstaVu incompatible modes InstaVu mode disallows selection of Math waveforms If you attempt to select a math waveform from the MORE menu the oscilloscope will display an error message Either switch InstaVu off and create the math waveform or select a channel waveform and continue using InstaVu mode Using FastFrame TDS 700A Models Only Real Time Fast Frame 3 46 You can define and enable FastFrame also called segmented memory This feature lets you capture multiple acquisitions in the acquisition memory of a single channel Figure 3 28 shows how FastFrame combines the desired captured records into one larger record For example FastFrame would let you store 10 records of 500 samples each into one record with a 5000 sample length roa rT ro gt gt po Sey Ld Li rmn Sr fee a AO E Figure 3 28 Fast Frame TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms If you are using the FastFrame mode you can jump to the desired frame To use FastFrame do the following steps 1 Press HORIZONTAL MENU gt FastFrame Setup main gt FastFrame side to toggle on or off the use of FastFrame see Figure 3 29 Press Frame Length or Frame Count side and use the general purpose knob to enter Fas
236. ollows m In Auto mode the oscilloscope acquires a waveform after a specific time has elapsed even if a trigger does not occur The amount of time the oscilloscope waits depends on the time base setting Auto mode triggering is not available in InstaVu mode see Incompatible Modes on page 3 45 m In Normal mode the oscilloscope acquires a waveform only if there is a valid trigger 2 To change the holdoff time press Holdoff side Enter the value in time using the general purpose knob or the keypad If you want to enter a large number using the general purpose knob press the SHIFT button before turning the knob When the light above the SHIFT button is on and the display says Coarse Knobs in the upper right corner the general purpose knob speeds up significantly You can set holdoff from 250 ns minimum holdoff available to 12 seconds maximum available See Holdoff Variable Main Trigger in the TDS 684A TDS 744A and TDS 784A Performance Verification and Specifications manual for typical minimum and maximum values TDS 684A TDS 744A amp TDS 784A User Manual 3 59 Triggering on Waveforms To Set Slope a AS To Set Level 3 To change to the factory default holdoff setting for the current horizontal scale setting press Default Holdoff side NOTE If you select Default Holdoff the default holdoff time will vary with the horizontal scale setting to maintain a good value for general purpose triggering at that
237. om Selected File side to complete the operation r Tek Run 100kS 5 Sample A Save Current Setup uJ To File To Setup1 factory To Setup 2 factory To Setup3 factory 20 0m gt M 500us Chis 27 2mv maton o OIl acai E i HH ENE eet tag Saved Current Factory Utilities Setup Setu Setup OCC oaoa ka Figure 3 65 Save Recall Setup Menu 3 112 TDS 684A TDS 744A amp TDS 784A User Manual Saving Waveforms and Setups Recalling a setup will not change the menu that is currently displayed If you recall a setup that is labeled factory in the side menu you will recall the factory setup The conventional method for recalling the factory setup is described below To Recall the To reset your oscilloscope to the factory defaults Factory Setu y P Press SAVE RECALL SETUP gt Recall Factory Setup main gt OK Confirm Factory Init side See Factory Initialization Settings on page D 1 for a list of the factory defaults To Delete All Setups and Sometimes you might use the oscilloscope to acquire waveforms that are Waveforms Tek confidential Furthermore before returning the oscilloscope to general usage Secure you might want to remove all such waveforms and any setups used to acquire them Be sure you want to remove all waveforms and setups because once they are removed yo
238. om the More menu 2 Press ZOOM 3 TDS 684A only Press ON side in the Zoom menu The ZOOM front panel button should light up TDS 700A models only Press ZOOM Mode main gt ON side The ZOOM front panel button should light up Toggle Dual Zoom to OFF in the side menu 4 Adjust the vertical zoom factor for the selected waveform using the vertical SCALE knob Adjust the vertical position of the zoomed waveform using the vertical POSITION knob TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms 5 Adjust the horizontal zoom factor using the horizontal SCALE knob Adjust the horizontal position of the zoomed waveform using the horizontal POSITION knob Depending on the selection for Horizontal Lock in the side menu Zoom affects the displayed waveforms as follows None only the waveform currently selected can be magnified and positioned horizontally Figure 3 23 Live all live as opposed to reference waveforms can be magnified and positioned horizontally at the same time If a reference or math waveform is selected and Horizontal Lock set to Live only the selected reference or math waveform is magnified and positioned All all waveforms displayed live math and reference can be magnified and positioned horizontally at the same time Tek Run 100kS s Only the selected waveform the top one changes size H Horizontal Lock
239. on Waveforms Tek Run 100kS s Sample am 2 Runt Width Slewrate KARN e Polarity T citech Level lode Type Class amp amp lt Pulse gt lt oliteh gt CP width Accert 48mv BRENT M 5004s Glitch Chi Mode amp Holdoff Normal Default Holdoff 2 5 nis Holdoff i8 4ms CoD CD CD CD Figure 3 44 Main Trigger Menu Glitch Class LOC OC C O Select the Source To specify which channel becomes the pulse trigger source Press TRIGGER MENU gt Type main gt Pulse pop up gt Source main gt Ch1 Ch2 Ch3 or Ch4 side The source selected becomes the trigger source for all four trigger classes Select the Polarity amp Width To specify polarity positive negative or either and width of the glitch do the following steps 1 Press TRIGGER MENU Type main gt Pulse pop up gt Polarity amp Width main gt Positive Negative or Either side or keypad i Positive looks at positive going pulses y Negative looks at negative going pulses TU UY Either looks at both positive and negative pulses Fie 2 Press Width side and set the glitch width using the general purpose knob Set to Accept or Reject Glitch To specify whether to trigger on glitches or ignore glitches press TRIGGER MENU gt Type mai
240. one template you can compare one channel to one template and the other channel to another template Now specify the action to take if waveform data exceeds the limits set by the limit test template and turn on limit testing 1 Press SHIFT ACQUIRE MENU gt Limit Test Setup main to bring up a side menu of possible actions 2 Ensure that the side button corresponding to the desired action reads ON m If you want to send a hardcopy command when waveform data exceeds the limits set toggle Hardcopy if Condition Met side to ON You can set the hardcopy system to send the hardcopy to the file system Do not forget to set up the hardcopy system See Hardcopy on page 3 120 for details m If you want the bell to ring when waveform data exceeds the limits set toggle Ring Bell if Condition Met side to ON m f you want the oscilloscope to stop when waveform data exceeds the limits set toggle Stop After Limit Test Condition Met side to ON TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications NOTE The button labeled Stop After Limit Test Condition Met corresponds to the Limit Test Condition Met menu item in the Stop After main menu You can turn this button on in the Limit Test Setup menu but you cannot turn it off In order to turn it off press Stop After and specify one of the other choices in the Stop After side menu 3 Ensure that Limit Test side reads ON If it reads OFF press
241. onfigure Hardware Software eos Hardcopy Rats Setup DIGIC OIC IO C Figure 3 70 Utility Menu System I O Set Hardcopy Parameters To specify the hardcopy format layout and type of port using the hardcopy menu do the following steps 1 Press SHIFT gt HARDCOPY MENU to bring up the Hardcopy menu 2 Press Format main gt Thinkjet Deskjet Laserjet Epson DPU 411 DPU 412 PCX PCX Color TIFF BMP Mono BMP Color RLE Color EPS Mono Img EPS Color Img EPS Mono Plt EPS Color Plt Interleaf or HPGL side Press more side to page through all of these format choices 3 Press SHIFT gt HARDCOPY MENU gt Layout main gt Landscape or Portrait side See Figure 3 71 3 122 TDS 684A TDS 744A amp TDS 784A User Manual Saving Waveforms and Setups Landscape Format Portrait Format Figure 3 71 Hardcopy Formats 4 Press SHIFT gt HARDCOPY MENU gt Palette main gt Hardcopy or Current side to specify a hardcopy palette Current uses the current palette settings to create the hardcopy while Hardcopy sets the hardcopy palette to an optimal setting for hardcopy devices 5 Press SHIFT gt HARDCOPY MENU gt Port main to specify the output channel to send your hardcopy through The choices are GPIB RS 232 Centronics and File The menu item File chooses the floppy disk drive as the destination for hardcopies See To Save to a Floppy Disk on pag
242. ons in a waveform record m Graticule for making quick estimates by counting graticule divisions on screens This section also tells you how to use Probe Cal and Signal Path Compensation to optimize the accuracy of your measurements Cursor Automated Graticule Readouts Measurements Chl Frequency 100 MHz Ch 1 Period 10 ns Cursors Figure 3 51 Graticule Cursor and Automated Measurements Taking Automated Measurements The TDS Oscilloscope provides the feature Measure for automatically taking and displaying waveform measurements This subsection describes how to set up the oscilloscope to let it do the work of taking measurements for you Because automatic measurements use the waveform record points they are generally more accurate and quicker than cursor and graticule measurements The oscilloscope will continuously update and display these measurements TDS 684A TDS 744A amp TDS 784A User Manual 3 87 Measuring Waveforms Measurement List Automatic measurements are taken over the entire waveform record or if you specify gated measurements see page 3 91 over the region specified by the vertical cursors Automated measurements are not taken just on the displayed portions of waveforms The oscilloscope can also display almost all of the measurements at once see Take a Snapshot of Measurements on page 3 95 The TDS Oscilloscope provides you with 25 autom
243. oose from Normal Bold Hardcopy Preview or Monochrome 3 Ifyou are using a persistence display and want to vary the color of each point depending on its persistence choose Persistence Palettes Then choose Temperature Spectral or Gray Scale from the resulting side menu Choose View Palette to preview your selection on the display Press Persistence Palette to quit preview mode Press Clear Menu to return to the Palette menu NOTE Use at higher room temperatures or with higher intensity display formats such as the white fields in the Hardcopy Preview palette can temporarily degrade display quality You can select the Hardcopy Preview palette when using certain color hardcopy formats The default colors in the this palette comprise a white background and fully saturated primary colors which generally produce the best result To change the color of the current palette select a color and vary these attributes Hue which is the wavelength of light reflected from the surface It varies continuously along the color spectrum as produced by a rainbow Lightness which is the amount of light reflected from the surface It varies from black to the nominal color to white Saturation which is the intensity of color Completely desaturated color is gray Completely saturated color of any hue is that color at its most intense level 1 Select the main menu Change Colors item See Figure 3 20 2 Select one of the 13 colors by pres
244. ope sets the offset as close to the requested value as possible An offset request of 0 0 insures that the zoom boxes are butted up against each other regardless of the zoom factor The horizontal zoom and scale factors determine the minimum offset time available Both zoom boxes always enclose equal amounts of time with the second box always offset from the first by a time equal to one box Doubling the TDS 684A TDS 744A amp TDS 784A User Manual 3 41 Acquiring and Displaying Waveforms zoom factor halves the time enclosed by either box and therefore halves the minimum offset time The oscilloscope retains any value input that is less than the minimum time available as a request if you enter that value using the keypad Increasing the zoom factor or decreasing the horizontal scale to a setting that allows the requested value sets offset time to that value You cannot set offset to less than the minimum offset time available when using the general purpose knob Tek Run SA sample T Time 412 605 i Selected Graticule Zoom Mode f fel of jeie Zoomed Waveform Edges P a vi w SM 250mv Zoom Boxes ia on mu Dual Zoom ON Unzoomed Waveform s00mva M 100ns Chif 78omv Kos pa Pag foe Ra e ae shi m DZ Offset 412 625 S FF ae ie ee DP ra i pias Lig P ee a Mode Lock Graticule Reset
245. or a second waveform or the second middle reference of the same waveform Used in delay time calculations Typically set to 50 You can set it from 0 to 100 or to a voltage level TDS 684A TDS 744A amp TDS 784A User Manual Appendix B Algorithms Other Variables The oscilloscope also measures several values itself that it uses to help calculate measurements RecordLength is the number of data points in the time base You set it with the Horizontal menu Record Length item Start is the location of the start of the measurement zone X value It is 0 0 samples unless you are making a gated measurement When you use gated measurements it is the location of the left vertical cursor End is the location of the end of the measurement zone X value It is RecordLength 1 0 samples unless you are making a gated measurement When you use gated measurements it is the location of the right vertical cursor Hysteresis The hysteresis band is 10 of the waveform amplitude It is used in MCross1 MCross2 and MCross3 calculations For example once a crossing has been measured in a negative direction the waveform data must fall below 10 of the amplitude from the MidRef point before the measurement system is armed and ready for a positive crossing Similarly after a positive MidRef crossing waveform data must go above 10 of the amplitude before a negative crossing can be measured Hysteresis is useful when you are
246. or the keypad to set the parameter you have chosen to the value desired The format when using the keypad is day month For example use 23 6 for the 234 of June 3 Repeat steps 1 and 2 to set other parameters as desired 4 Press OK Enter Date Time side to put the new settings into effect This sets the seconds to zero NOTE When setting the clock you can set to a time slightly later than the current time and wait for it to catch up When current time catches up to the time you have set pressing Ok Enter Date Time side synchronizes the set time to the current time 5 Press CLEAR MENU to see the date time displayed with the new settings 3 124 TDS 684A TDS 744A amp TDS 784A User Manual Saving Waveforms and Setups To Print Directly toa To make your hardcopies use the procedures that follow Hardcopy Device Connect to a Hardcopy Device To connect the oscilloscope directly to a hardcopy device determine which interface and cable the device uses and connect accordingly See Figure 3 73 Some devices such as the Tektronix HC100 Plotter use the GPIB interface Many printers such as the Tektronix HC200 use Centronics interfaces Many hardcopy devices including the HC100 and HC200 with option 03 provide RS 232 support Check the documentation for your hardcopy device Digitizing Oscilloscope Hardcopy Device GPIB RS 232 or Centronics Cable Figure 3 73 Connecting th
247. ore the end of pretrigger holdoff However the button has no effect if the acquisition system is stopped TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms To Single Trigger To trigger on the next valid trigger event and then stop press SHIFT FORCE TRIG Now press the RUN STOP button each time you want to initiate the single sequence of acquisitions To leave Single Trig mode press SHIFT ACQUIRE MENU gt Stop Af ter main RUN STOP Button Only side See the description under Stop After on page 3 25 for further discussion of single sequence acquisitions Single sequence triggering is not available in InstaVu mode see Incompatible Modes on page 3 45 To Check Trigger Status To ascertain the state and setup of the triggering circuit use the trigger status lights readout and screen Trigger Status Lights To quickly determine trigger status check the three status lights TRIG D READY and ARM in the Trigger control area See Fig ure 3 33 m When TRIG D is lighted it means the oscilloscope has recognized a valid trigger and is filling the posttrigger portion of the waveform m When READY is lighted it means the oscilloscope can accept a valid trigger event and the oscilloscope is waiting for that event to occur m When ARM is lighted it means the trigger circuitry is filling the pretrigger portion of the waveform record m When both TRIG D and READY are lighted it means the osc
248. orm Math waveforms 3 144 Disallowed in InstaVu 3 46 Math Color menu 3 35 Math1 2 3 More menu 3 144 Maximum 3 89 Glossary 6 Mean 3 89 Glossary 6 MEASURE button 3 90 Measure Delay menu Create Measrmnt 3 95 Delay To 3 94 Edges 3 95 Measure Delay To 3 94 OK Create Measurement 3 95 Measure Delay To Measure Delay menu 3 94 Measure menu 3 90 3 95 Gating 3 91 High Ref 3 94 High Low Setup 3 92 Histogram 3 92 Low Ref 3 94 Mid Ref 3 94 Mid Ref 3 94 Min Max 3 92 Reference Levels 3 93 Remove Measrmnt 3 91 3 95 Select Measrmnt 3 90 3 94 Set Levels in units 3 93 Snapshot 3 95 Measurement Amplitude 3 88 Glossary 1 Area 3 88 Glossary 1 Burst width 3 88 Glossary 2 Cycle area 3 88 Glossary 3 Cycle mean 3 88 Glossary 3 Cycle RMS 3 88 Glossary 3 Delay 3 94 Glossary 3 Duty cycle 2 20 Glossary 6 Glossary 8 TDS 684A TDS 744A amp TDS 784A User Manual Index Fall time 3 88 Frequency 2 19 3 88 Glossary 4 Gated Glossary 4 High 3 88 Glossary 5 Low 3 89 Glossary 6 Maximum 3 89 Glossary 6 Mean 3 89 Glossary 6 Minimum 3 89 Glossary 6 Negative duty cycle 3 89 Negative overshoot 3 89 Negative width 3 89 Overshoot Glossary 8 Peak to peak 3 89 Glossary 7 Period 3 89 Glossary 7 Phase 3 89 Glossary 7 Positive duty cycle 3 89 Positive overshoot 3 89 Positive width 3 89 Prop
249. orm FFTs 3 144 Waveform integration 3 165 Waveform memory 3 115 WAVEFORM OFF button 2 18 3 8 3 32 Waveform record FFT 3 150 FFT frequency domain 3 151 length of 3 151 FFT source 3 150 acquisition mode 3 154 defined 3 151 long versus short 3 153 FFT time domain 3 151 3 152 Waveform Display menu 3 29 Waveforms And zoom 3 37 Math 3 144 Scaling and positioning 3 9 Waveforms Status menu 3 133 Width 2 20 Glossary 7 Glossary 8 Width trigger 3 71 3 76 How to set up 3 76 3 86 Width Main Trigger menu 3 73 Window 3 158 Blackman Harris 3 148 3 158 3 161 characteristics of 3 160 Hamming 3 148 3 158 3 161 Hanning 3 148 3 158 3 161 rectangular 3 147 3 158 3 161 rectangular vs bell shaped 3 160 TDS 684A TDS 744A amp TDS 784A User Manual Index selecting 3 158 Windowing process 3 158 Windows descriptions of 3 147 3 148 X XY Format 3 31 Incompatible with InstaVu 3 45 XY format Glossary 11 XY Display menu 3 31 Y YT Format 3 31 YT format Glossary 11 YT Display menu 3 31 Z Zero phase reference point 3 151 3 156 establishing for impulse testing 3 156 3 157 TDS 684A TDS 744A amp TDS 784A User Manual Zoom 3 37 3 48 And interpolation 3 38 And waveforms 3 37 derivative math waveforms 3 165 Dual Window mode 3 40 Dual Zoom 3 41 Dual Zoom Offset 3 41 Horizontal lock 3 39 Incompatible with InstaVu 3 4
250. ormation of that time domain data record into an FFT frequency domain record The resulting frequency domain record is one half the length of the FFT input because the FFT computes both positive and negative frequencies Since the negative values mirror the positive values only the positive values are displayed FFT Time Domain Record FFT Frequency Domain Record Figure 3 91 FFT Time Domain Record vs FFT Frequency Domain Record FFT Frequency Range and Resolution When you turn on an FFT waveform the oscilloscope displays either the magnitude or phase angle of the FFT frequency domain record The resolution between the discrete frequencies displayed in this waveform is determined by the following equation _ Sample Rate AF FFT Length Where AF is the frequency resolution Sample Rate is the sample rate of the source waveform FFT Length is the length of the FFT Time Domain waveform record The sample rate also determines the range these frequencies span they span from 0 to the sample rate of the waveform record The value of 4 the sample rate is often referred to as the Nyquist frequency or point For example a sample rate of 20 Megasamples per second would yield an FFT with a range of 0 to 10 MHz The sample rates available for acquiring data records vary over a range TDS oscilloscopes display the sample rate in the acquisition readout at the top of the oscilloscope screen TDS 684A TDS 744A amp TDS 784A User Manual
251. oscope goes through for each delayed mode Acquire A Data Wait for Main Trigger Wait User specified Time Figure 3 47 Delayed Runs After Main Wait for Delayed Trigger Event Wait for Main Trigger Wait User specified ime fl Wait the User specified Number of Delayed Trigger Events Wait the User specified Number of Delayed Trigger Events Wait User specified Time Figure 3 48 Delayed Triggerable The oscilloscope is always acquiring samples to fill the pretrigger part of the waveform record When and if delay criteria are met it takes enough posttrigger samples to complete the delayed waveform record and then displays it Refer to Figure 3 49 for a more detailed look at how delayed records are placed in time relative to the main trigger 3 81 Triggering on Waveforms Pretrigger Record Posttrigger Record Delayed Runs After Main Main Tigger Point Delayed Trigger Waveform Record gt Main Trigger Source a on wart From Horiz Menu Start Posttrigger Acquisition Delayed Triggerable By Events Main Trigger Point k si Trigger Waveform Record Main Trigger Source Delayed N N N N N N N N N Trigger Source l x A Fras ke Start P osttrigger Acquisition Trigger Waiting for nth Event on nth Delayed Trigger Event Where n 5 Delayed Triggerable By Time k jaiii Trigger Waveform Record
252. ositioning Waveforms To Check Position The TDS Oscilloscope allows you to scale change the vertical or horizontal size and position move up down left or right waveforms on screen for best display Figure 3 5 shows the results of both vertical and horizontal scaling and positioning This subsection first tells you how to quickly check and set vertical and horizontal scales positions and other parameters such as vertical bandwidth and horizontal record length To quickly see the position of the waveform in the display check the Channel Reference and the Record View icons See Figure 3 5 TDS 684A TDS 744A amp TDS 784A User Manual 3 9 Acquiring and Displaying Waveforms The Channel Reference icon at the left side of the display points to ground on the waveform record when offset is set to 0 V The oscilloscope contracts or expands the selected waveform around this point when you change the vertical scale The Record View at the top of the display indicates where the trigger occurs and what part of the waveform record is displayed Record View gt _ H eF E Channel Reference Icon To Check the Vertical Scale To Change Vertical Scale and Position Original P osition Positioned Vertically Positioned Horizontally
253. ou control over many vertical channel parameters See Figure 2 12 Although there can be more than one channel displayed the vertical menu and buttons only adjust the selected channel Each menu item in the Vertical menu displays a side menu Right now the Coupling item in the main menu is highlighted which means that the side menu shows the coupling choices At the top of the side menu the menu title shows the channel affected by the menu choices That channel always matches the lighted channel button Tek Run 100kS 5 Sample ch2 Coupling Side Menu Title i a oS Impedance Ch2 Reference Indicator hyggjaran punanna ac chi 200mv roomv_ M 500us Chi 252mV o EA 5e Em bandwidth M2 Scale position offset Cal Probe Full omV 2 96 div av initialized 111 91 91 OIOI Figure 2 12 The Vertical Main Menu and Coupling Side Menu TDS 684A TDS 744A amp TDS 784A User Manual 2 17 Tutorial 7 Press Q side to toggle the selection to 50 Q That changes the input coupling of channel 2 from 1 MQ to 50 Q The channel readout for channel 2 near the bottom of the graticule now shows an Q indicator Assign Controls to Pressing a channel CH button sets the vertical controls to that channel It also Another Channel adds the channel to the display if that waveform is not alre
254. our hardcopy device is connected to such as LPT1 or LPT2 For example to copy print a file called screen to a printer attached to the pt parallel port type copy screen Iptl B Your hardcopy device should now print a picture of the oscilloscope screen NOTE If you transmit hardcopy files across a computer network use a binary 8 bit data path Communicating with Remote Instruments 3 128 The TDS Oscilloscope can connect into a system environment so that you can control it remotely or exchange measurement or waveform data between it and a computer This subsection explains how to prepare and setup the oscilloscope for control and operation over the IEEE Std 488 2 1987 GPIB interface TDS 684A TDS 744A amp TDS 784A User Manual Saving Waveforms and Setups To Prepare for Remote To transfer data between the oscilloscope and other instruments over the GPIB Operation do the following tasks to make sure the instruments support GPIB protocols and observe GPIB Interface requirements Check for GPIB Protocols Make sure the instruments to be connected support the GPIB protocols These protocols cover Remote instrument control Bidirectional data transfer m Device compatibility m Status and event reporting To simplify the development of GPIB systems include instruments that use Tektronix defined codes and formats for messages that travel over the GPIB Each device that follows these codes and fo
255. ovide you with hardcopies of its display To obtain a hardcopy you need to know how to configure the communication and hardcopy parameters of the oscilloscope how to connect it to one of the many hardcopy devices it supports and how to print the hardcopy This subsection describes how to do these tasks and how to save a hardcopy to a floppy disk TDS 684A TDS 744A amp TDS 784A User Manual Saving Waveforms and Setups Supported Formats The oscilloscope prints hardcopies of its display in many formats which allows you to choose from a wide variety of hardcopy devices It also makes it easier for you to place oscilloscope screen copies into a desktop publishing system The oscilloscope supports the following formats m HP Thinkjet inkjet printer m HP Deskjet inkjet printer m HP Laserjet laser printer m Epson m DPU 411 II portable thermal printer m DPU 412 portable thermal printer PCX PC Paintbrush m PCX Color PC Paintbrush TIFF Tag Image File Format BMP Mono Microsoft Windows file format BMP Color Microsoft Windows file format m RLE Color Microsoft Windows color image file format compressed m EPS Mono Image Encapsulated Postscript mono image m EPS Color Image Encapsulated Postscript color image m EPS Mono Plot Encapsulated Postscript mono plot m EPS Color Plot Encapsulated Postscript color plot m Interleaf m HPGL Color Plot Depending on the output format selected the o
256. p up gt Class main gt Setup Hold pop up gt Set Hold Times main gt Setup Time or Hold Time side See Figure 3 42 2 Turn the general purpose knob or use the keypad to set values for the setup and for the hold times NOTE Keep hold time to at least 2 ns less than the clock period or the oscillo scope cannot trigger TDS 684A TDS 744A amp TDS 784A User Manual 3 69 Triggering on Waveforms Cursors measure the setup hold violation zone which equals setup time hold time 30 ns Data Ch1 transition occurs within 10 ns after the clock violating hold time limit The oscilloscope recognizes the violation and triggers at the clock edge Triggering on Pulses 3 70 Positive setup time always leads the clock edge positive hold time always follows the clocking edge Setup time always leads the hold time by at least 2 ns Ts Ty 22 ns Attempting to set either time to reduce the 2 ns limit adjusts the other time to maintain the limit Z Tek Run 5 00GS 5 Average i Hold Time 30 0ns amp 30 i Setup Hold Times a eee Setup Time i fy 10 0ns C1 C2 Dly E Tae fo fe A 10 54ns A gold ie 4 1 00 ve M 10 0ns StHid ch2 LOO C O oh i Source Class 3 sour Kag a lt StHid gt cha Hee Hobioft I 1 D1 1 Type lt Logic gt Fig
257. p you use Zoom effectively consider how it is affected by interpolation When you zoom on a waveform you expand a portion of it If the expansion requires the oscilloscope to show more points for that portion than it has acquired it interpolates The method the oscilloscope uses to interpolate linear or sin x x can affect the way Zoom displays your waveform If you selected sin x x the default it may introduce some overshoot or undershoot to the waveform edges If such is the case change the interpolation method to linear following the instructions on page 3 40 To read about the two interpolation methods see Interpolation on page 3 18 To differentiate between the real and interpolated samples set the display style to Intensified Samples See Select the Display Style on page 3 28 To quickly determine the zoom factor of a zoomed waveform select it and check the Zoom readout It shows the selected waveform by number along with the horizontal and vertical expansion factors The Zoom readout appears at the top of the display when zoom is on See Figure 3 23 on page 3 39 The TDS 700A models do not display the Zoom readout when in dual window preview mode To use Zoom select a waveform turn Zoom on and magnify that waveform using the vertical and horizontal scale knobs 1 Press any of waveform selection buttons CH 1 through CH 4 on the right side of the display Or press MORE and select a math or reference waveform fr
258. page 3 91 with Snapshot exactly as you would when you display individual measurements from the Select Measrmnt menu TDS 684A TDS 744A amp TDS 784A User Manual Measuring Waveforms To Find More Information To perform a tutorial that shows you how to take automatic measurements see Example 3 Taking Automated Measurements on page 2 19 To learn how the oscilloscope calculates each automatic measurement see Appendix B Algorithms on page B 1 Taking Cursor Measurements Cursor Types Horizontal Bar Cursors Figure 3 58 Cursor Types The TDS Oscilloscope provides cursors that measure the difference either in time or voltage between two locations in a waveform record This section describes cursors how to select their type and mode how to display them and how to use them to take measurements Cursor measurements are fast and easy to take Cursors are made up of two markers that you position with the general purpose knob You move one cursor independently or both cursors in tandem depending on the cursor mode As you position the cursors readouts on the display report and update measurement information There are three cursor types horizontal bar vertical bar and paired see Figure 3 58 WV x Vertical Bar Cursors Paired Cursors Horizontal bar cursors measure vertical parameters typically volts Vertical bar cursors measure horizontal parameters typically time
259. pe creates waveform records differently depending on the number of input channels turned on See Table 3 4 for the TDS 744A or Table 3 5 for the TDS 784A Table 3 4 TDS 744A Sampling Mode Selection When Fit to Screen is Off Time Base One Channel Two Channels Three or Four Channels gt 50ns Real time Real time Real time 50ns Real time Real time E quiv time or interpolate 25ns Real time Equiv time or interpolate Equiv time or interpolate lt 25ns Equiv time orInterpolate Equiv time or Interpolate Equiv time or Interpolate 1 gt means slower than lt means faster than TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms Table 3 5 TDS 784A Sampling Mode Selection When Fit to Screen is Off Time Base One Channel Two Channels Three or Four Channels gt 25 ns Real time Real time 25ns Real time Real time E quiv time or interpolate 12 5ns Real time Equiv time or interpolate Equiv time or interpolate lt 12 5ns Equiv time orInterpolate Equiv time or Interpolate Equiv time or Interpolate 1 gt means slower than lt means faster than NOTE The oscilloscope will use the interpolation method selected in the display menu to fill in the missing record points either linear or sin x x interpolation See Interpolation on page 3 18 for a discussion of interpolation Stop Aft
260. peed To change the cursors speed press SHIFT before turning the general purpose knob The cursor moves faster when the SHIFT button is lighted and the display reads Coarse Knobs in the upper right corner Select Time Units You can choose to display vertical bar cursor results in units of time or fre quency If you have Option 5 Video you can also display the results in terms of video line number To choose vertical bar cursor units do the following step Press CURSOR gt Time Units main gt seconds or 1 seconds Hz or with Option 5 Video Line Number side Select Amplitude Units If you are measuring NTSC signals you can choose to display vertical readings in IRE units If you are trying to measure such a signal you should have Option 05 Video Trigger installed as it would be difficult to trigger on composite video waveforms without Option 05 To switch between IRE and base cursor units do the following steps 1 Press CURSOR Amplitude Units main gt IRE NTSC 2 To return to normal press CURSOR Amplitude Units main gt Base To Find More Information To find instructions for using cursors with math waveforms see Waveform Math on page 3 142 To find instructions on using cursor with FFT waveforms differentiated waveforms and integrated waveforms see Fast Fourier Transforms on page 3 144 Waveform Differentiation on page 3 161 and Waveform Integration on page 3 165 To find information on cursor units wi
261. pendix D Factory Initialization Settings Recalling the factory setup establishes the initialization settings shown in Table D 1 to set the TDS Oscilloscope to a known default state Table D 1 Factory Initialization Defaults Control AC AC quire mode quire repetitive signal TDS 700A models only Changed by Factory Init to Sample ON Enable ET AC quire stop after RUN STOP button only AC AC quire of averages quire of envelopes Channel selection 16 10 Channel 1 on all others off Cursor H Bar 1 position Cursor H Bar 2 position 10 of graticule height 3 2 divs from the center 90 of the graticule height 3 2 divs from the center Cursor V Bar 1 position 10 of the record length Cursor V Bar 2 position 90 of the record length Cursor amplitude units Base Cursor function Off Cursor mode Independent Cursor time units Seconds Date and time No change Delayed edge trigger coupling Main Trigger Delayed edge trigger level OV Delayed edge trigger slope Rising Delayed edge trigger source Channel 1 Delay trigger average 16 Delay trigger envelope 10 Delay events triggerable after main 2 Delay time 16 ns Delayed delay by Delay by Time Delayed time base mode Delayed Runs After Main Display clock No Change TDS 684A TDS 744A amp TDS 784A User Manual Appendix D Factory Initialization S ettings Table D 1 Factory Initial
262. ple Readout Options Display T Trigger Point Trigger Bar Style tong Displa Y Date Time ON 50 0mv C MT ooms Chit 6amv Style z Readout Filter Graticule Format Settings Intensity 7 i lt Display gt Vectors leidtace Sin x x Full VF SeS Figure 3 18 Trigger Point and Level Indicators TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms Select Interpolation Filter The display filter types are sin x x interpolation and linear interpolation To switch between interpolation filters Press DISPLAY gt Filter main gt Sin x x Interpolation or Linear Interpo lation side NOTE When the horizontal scale is set to the faster rates 10 ns div for the TDS 684A see Tables 3 4 and 3 5 beginning on page 3 24 for rates specific to the two TDS 700A models or when using the ZOOM feature to expand waveforms horizontally interpolation occurs The filter type linear or sin x x depends on which is set in the Display menu Otherwise interpola tion is not used See Interpolation on page 3 18 for a discussion of interpolation Select the Graticule Type To change the graticule Press DISPLAY Graticule main gt Full Grid Cross Hair Frame NTSC or PAL side Full provides a grid cross hairs and a frame Grid displays a
263. put signal m AC coupling shows only the alternating components of an input signal m Ground GND coupling disconnects the input signal from the acquisition m Input impedance lets you select either 1 M Q or 50 Q impedance NOTE If you select 50 Q impedance with AC coupling the digitizing oscillo scope will not accurately display frequencies under 200 kHz Also when you connect an active probe to the oscilloscope such as the P6245 the input impedance of the oscilloscope automatically becomes 50 Q If you then connect a passive probe like the P6139A you need to set the input impedance back to 1 MQ The maximum volts div setting is reduced from 10 V to 1 V when you select 50 Q impedance See the discussion Input Impedance Considerations on page 3 5 Bandwidth Bandwidth refers to the range of frequencies that an oscilloscope can acquire and display accurately that is with less than 3 dB attenuation To select the upper limit for the higher frequency components change the bandwidth of the selected channel Press VERTICAL MENU gt Bandwidth main gt Full 250 MHz or 20 MHz side Fine Scale To make fine adjustments to the vertical scale press VERTICAL MENU gt Fine Scale main and use the general purpose knob or the keypad Position To adjust the vertical position to a specific number of divisions press VERTICAL MENU gt Position main and use the general purpose knob or the keypad to set the offset value
264. r Manual Acquiring and Displaying Waveforms Customizing the Display Color Change the Display Color Choose a Palette The TDS Oscilloscope can display information in different colors This subsection describes how to use the Color menu to choose the colors in which the various display objects appear To bring up the Color menu 1 Press DISPLAY to show the Display menu 2 Press Settings in the main menu until you select Color from the pop up menu See Figure 3 19 z Tek Run 250kS 5 Sample Palettes Normal Bold Hardcopy Preview Monochrome Persistence Palettes Change ap Restore Colors lor Colors Settings lt Color gt ee ee ee ee aSa Figure 3 19 Display Menu Setting The Color menu allows you to alter color settings for various display compo nents such as waveforms and text The Display menu allows you to adjust the style intensity level graticule and format features To find more information on display see Change the Display Settings on page 3 28 To choose a palette of 13 colors from a menu of preset palettes 1 Choose the starting palette by selecting Palette from the main menu TDS 684A TDS 744A amp TDS 784A User Manual 3 33 Acquiring and Displaying Waveforms Change the Palette Colors 3 34 2 Select one of the available palettes in the side menu Ch
265. r less than then it triggers a waveform display at the point the logic condition became FALSE This time can be and usually is different from the time set for TRUE for more than or TRUE for less than In Figure 3 41 the delay between the vertical bar cursors is the time the logic function is TRUE Since this time is more 216 us than that set in the TRUE for more than menu item 150 us the oscilloscope issues the trigger at that point not at the point at which it has been TRUE for 150 us ae 5 Tek Stopped 4671 Acquisitions True gt 150 0000us i A 216us Logic Pattern Sts Trig When Goes TRUE Time Logic Function is TRUE Logic Function AND Becomes TRUE E 4 Goes Dor FALSE TRUE for less than 7 i r r ens Logic Function Becomes FALSE and i l EA Triggers Acquisition T ETAn Chi s0omva fcha Ss0omva M 100ps eae iG inet ae a ake anr A araia aa Type Class Logic when amp stogic gt lt Pattern gt Inputs AND True gt Thresholds Holdoff 111 1 1 LOIDIDIOI O Time Logic Function Must be TRUE Figure 3 41 Logic Trigger Menu Time Qualified TRUE To State Trigger When you select the logic class State the oscilloscope uses channel 4 as a clock and triggers on a logic circuit made from the rest of the channels pages 3 60 through 3 62 d
266. rack that of its waveform m If you are comparing two or more waveforms to a common template that template will track the position of the failed waveform If more than one waveform fails during the same acquisition the template will track the position of the waveform in the highest numbered channel For example CH 2 is higher than CH 1 TDS 684A TDS 744A amp TDS 784A User Manual 3 141 Using Features for Advanced Applications Waveform Math The TDS Oscilloscope provides a means for you to mathematically manipulate your waveforms For example you might have a waveform clouded by background noise You can obtain a cleaner waveform by subtracting the background noise from your original waveform This section describes the invert add subtract divide and multiply waveform math features See Fast Fourier Transforms on page 3 144 Waveform Differ entiation on page 3 161 and Waveform Integration on page 3 165 for informa tion on Advanced DSP Math features To Use Single Wfm Math To perform waveform math use the More menu Figure 3 84 The More menu allows you to display define and manipulate three math waveforms the following steps explain how to create a math waveform based on a single source waveform 1 Press MORE gt Math Math2 or Math3 main gt Change Math waveform definition side gt Single Wfm Math main 2 To define the source waveform press Set Single Source to side repeatedly to cycle it to the de
267. rameter you can enter the value as a number using the keypad instead of using the knob Always end the entry of a number by pressing ENTER The numeric keypad also provides multipliers for engineering exponents such as m for milli M for mega and u for micro To enter these multiplier values press the SHIFT button and then press the multiplier 1 Press Low Ref side 2 On the numeric keypad press the 2 the 0 and the ENTER buttons which sets the low measurement reference to 20 Observe that the rise time value has changed 3 Press Remove Measrmnt main gt All Measurements side That returns the display to its original state TDS 684A TDS 744A amp TDS 784A User Manual Tutorial Displaying a Snapshot of You have seen how to display up to four individual automated measurements on Automated Measurements screen You can also pop up a display of almost all of the automated measure ments available in the Select Measrmnts side menus This snapshot of measure ments is taken on the waveform currently selected using the channel selection buttons As when displaying individual measurements you must have a stable display of your signal and that signal must have all the segments necessary for the measurement you want 1 Press Snapshot main to pop up a snapshot of all available single waveform measurements See Figure 2 17 The snapshot display includes the label Ch 1 meaning that the measure ments display
268. rce You can select any one of the four input channels The channel you select as a trigger source will function whether it is displayed or not AC Line Voltage is the trigger source most often used when you are looking at signals related to the power line frequency Examples include devices such as lighting equipment and power supplies Because the oscilloscope generates the trigger you do not have to input a signal to create the trigger Auxiliary Trigger is the trigger source most often used in doing digital design and repair For example you might want to trigger with an external clock or with a signal from another part of the circuit To use the auxiliary trigger connect the external triggering signal to the Auxiliary Trigger input connector on the oscilloscope rear panel The digitizing oscilloscope provides three standard triggers for the main trigger system edge pulse and logic Option 05 provides a video trigger The standard triggers are described individually starting on page 3 57 A brief definition of each type follows Edge is the basic trigger You can use it with both analog and digital test circuits An edge trigger event occurs when the trigger source the signal the trigger circuit is monitoring passes through a specified voltage level in the specified direction the trigger slope Pulse is a special purpose trigger primarily used on digital circuits The four classes of pulse triggers are glitch runt width an
269. rcise The positive width measurement is now removed from the display because you selected it after you saved the setup The step just performed completes the examples You can restore the default settings by pressing SETUP gt Recall Factory Setup main gt OK Confirm Factory Init side TDS 684A TDS 744A amp TDS 784A User Manual 2 25 Tutorial 2 26 TDS 684A TDS 744A amp TDS 784A User Manual Overview Acquiring and Displaying Waveforms This chapter describes in detail how to perform the operating tasks you must do to measure test process or save and document your waveforms It leads with three sections on the fundamental tasks of acquiring stably displaying and taking measurements on waveforms m Acquiring and Displaying Waveforms m Triggering on Waveforms m Measuring Waveforms Once you have acquired and measured waveforms you may want to save and restore them or the control setups used to acquire and measure them Or you may want to save the display screen complete with waveform and setup information to include them with the documents you produce with your desk top publishing system You may even want to digitally process them add multiply or divide them integrate differentiate or take an FFT of them The following two topics cover these tasks m Saving Waveforms and Setups m Using Features for Advanced Applications When performing any operation task you might want to display a comprehen sive lis
270. rea press CLEAR MENU See Figure 2 15 Remove Measurement Use the Measure menu to remove waveforms you no longer want To remove a Readouts measurement individually you can also remove them as a group do the following step 1 Press MEASURE Remove Measrmnt main gt Measurement 1 Measurement 2 and Measurement 4 side to remove those measurements Leave the rise time measurement displayed 2 20 TDS 684A TDS 744A amp TDS 784A User Manual Tutorial Tek Run 100kKS 5 Sample Ch1 Freq 999 44 HZ chi width 501s chi Rise 7usS Low resolution chi Duty 50 0 Oooo o i om a oops Chi F 248m SSA 8 Press to Remove Menus From Screen Figure 2 15 Four Simultaneous Measurement Readouts Change the Measurement By default the measurement system will use the 10 and 90 levels of the Reference Levels waveform for taking the rise time measurement You can change these values to other percentages or change them to absolute voltage levels To examine the current values press Reference Levels main gt High Ref ao side The General Purpose Knob The general purpose knob the large knob is now set to adjust the high reference level Figure 2 16 There are several important things to observe on the screen m The knob icon appears at the top of the screen The knob icon indicates that the
271. rement Period Frequency Ti Positive width a Negative width lot ice Tiram ter ESIE ER Remove Gating t Reference Measrmnt Setup Snapshot irae Vleasrmnat OFF Histogram Levels ea am awe ame aes Gas a 200mv M 50 0ns chi T 196mVY more LOOIDID IO Figure 3 35 Record View Trigger Position and Trigger Level Bar Readouts Trigger Position and Level Indicators To see the trigger point and level on the waveform display check the graphic indicators Trigger Position and Trigger Bar Figure 3 35 shows the trigger point indicator and trigger level bar TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms Both the trigger point indicator and level bar are displayed from the Display menu See Set Display Readout Options on page 3 29 for more information The trigger point indicator shows position It can be positioned horizontally off screen especially with long record length settings The trigger level bar shows only the trigger level It remains on screen regardless of the horizontal position as long as the channel providing the trigger source is displayed Trigger Status Screen To see a more comprehensive status listing of the settings for the main and delayed trigger systems press SHIFT STATUS gt STA TUS main
272. rent Setup main STOP Before doing step 2 that follows note that if you choose a setup location labeled user you will overwrite the user setup previously stored there You can store setups in setup locations labeled factory without disturbing previously stored setups TDS 684A TDS 744A amp TDS 784A User Manual 3 111 Saving Waveforms and Setups 2 To store to a setup internally choose one of the ten internal storage locations from the side menu To Setup 1 To Setup 2 see Figure 3 65 Now the current setup is stored in that location 3 To store a setup to disk press To File side Then use the general purpose knob to select the exact file from the resulting scrollbar list Finally press Save To Selected File side to complete the operation for storing setups Selecting this file in step 3 stores a setup in a uniquely named sequentially numbered file For instance the oscilloscope saves the first setup you save in the file TEKOO001 SET the second in TEK00002 SET and so on To Recall a Setup To recall a setup do the following steps 1 To recall a setup stored internally press SAVE RECALL SETUP gt Recall Saved Setup main gt Recall Setup 1 Recall Setup 2 side 2 To recall a setup stored on disk press From File side Then use the general purpose knob to select the exact file from the resulting scrollbar list Only files with set extensions will be displayed Finally press Recall Fr
273. riggers determine when the oscilloscope starts acquiring and displaying a waveform They help create meaningful waveforms from unstable jumbles or blank screens See Figure 3 30 The oscilloscope has four types of triggers edge logic pulse and with option 5 video Triggered Waveform Untriggered Waveforms Figure 3 30 Triggered Versus Untriggered Displays TDS 684A TDS 744A amp TDS 784A User Manual 3 49 Triggering on Waveforms The Trigger Event Trigger Sources ACM Trigger Types 3 50 The trigger event establishes the time zero point in the waveform record All points in the record are located in time with respect to that point The oscillo scope continuously acquires and retains enough sample points to fill the pretrigger portion of the waveform record that part of the waveform that is displayed before or to the left of the triggering event on screen When a trigger event occurs the oscilloscope starts acquiring samples to build the posttrigger portion of the waveform record displayed after or to the right of the trigger event Once a trigger is recognized the digitizing oscilloscope will not accept another trigger until the acquisition is complete You can derive your trigger from the following sources Input channels provide the most commonly used trigger sou
274. rizontal axis of the waveform Press SELECT to select the alternate cursor Align the selected cursor to another point of interest on the math waveform Read the frequency difference between the cursors from the A readout Read the frequency of the selected cursor relative to the zero frequency point from the readout The cursor units will always be in Hz regardless of the setting in the Time Units side menu The first point of the FFT record is the zero frequency point for the readout TDS 684A TDS 744A amp TDS 784A User Manual 3 149 Using Features for Advanced Applications To Take Automated Measurements of an FFT 3 150 The FFT Frequency Domain Record Tek Run 50 0MS s Sample LOO ID ICID UE M i 00us CRIS 1 34 V Math 10 0 dB 2 50MHz am Cm mm ms ms Figure 3 89 Cursor Measurement of an FFT Waveform 10 Press Function main gt Paired side 11 Use the technique just outlined to place the vertical bar of each paired cursor to the points along the horizontal axis you are interested in 12 Read the amplitude between the X of the two paired cursors from the top most A readout Read the amplitude of the short horizontal bar of the selected solid cursor relative to either 1 Vrms 0 dB ground 0 volts or zero phase level 0 degrees or 0 radians from the readout Read the
275. rm record input to the FFT This time domain record waveform becomes the FFT math waveform after it s transformed Its record length depends on the length of the waveform record defined above FFT Frequency Domain Record the FFT math waveform after digital signal processing converts data from the FFT time domain record into a frequency domain record Figure 3 90 compares the waveform record to the FFT time domain record Note the following relationships m For waveform records lt 10 K points in length the FFT uses all of the waveform record as input m For waveform records gt 10 K points the first 10 K points of the waveform record becomes the FFT time domain record m Each FFT time domain record starts at the beginning of the acquired waveform record m The zero phase reference point for a phase FFT math waveform is in the middle of the FFT time domain record regardless of the waveform record length FFT Time Domain Record gt Waveform Record Waveform Record lt 10 K Zero Phase Reference lt FFT Time Domain Record 10k Waveform Record gt 10 K Zero Phase Reference Figure 3 90 Waveform Record vs FFT Time Domain Record TDS 684A TDS 744A amp TDS 784A User Manual 3 151 Using Features for Advanced Applications 3 152 FFTs Transform Time Records to Frequency Records The FFT time domain record just described is input for the FFT Figure 3 91 shows the transf
276. rmats such as this oscilloscope supports standard commands Use of instruments that support these commands can greatly simplify development of GPIB systems Know the GPIB Interface Requirements To prepare to connect the oscilloscope to GPIB networks read and follow these rules m Connect no more than 15 devices including the controller to a single bus m Connect one device load every two meters about six feet of cable length to maintain bus electrical characteristics Generally each instrument represents one device load on the bus m Do not exceed 20 meters about 65 feet of the total cumulative cable length m Turn on at least two thirds of the device loads present when you use your network m Include only one cable path between devices on your network See Figure 3 75 Do not create loop configurations GPIB Device GPIB Device GPIB Device GPIB Device Figure 3 75 Typical GPIB Network Configuration GPIB Device GPIB Device GPIB Device TDS 684A TDS 744A amp TDS 784A User Manual 3 129 Saving Waveforms and Setups To Set Up for Remote Operation 3 130 Obtain the Proper Interconnect Cabling To connect the oscilloscope to a GPIB network obtain at least one GPIB cable Connecting two GPIB devices requires an IEEE Std 488 1 1987 GPIB cable available from Tektronix part number 012 0991 00 The standard GPIB cable connects to a 24 pin GPIB connector located on the rear panel
277. rms setup and hold times relative to a clock This subsection describes how to use these three classes of logic triggering pattern state and setup hold A pattern trigger occurs when the logic inputs to the logic function you select cause the function to become TRUE or at your option FALSE When you use a pattern trigger you define m The precondition for each logic input logic high low or do not care the logic inputs are channels 1 2 3 and 4 m The Boolean logic function select from AND NAND OR and NOR m The condition for triggering whether the trigger occurs when the Boolean function becomes TRUE logic high or FALSE logic low and whether the TRUE condition is time qualified A state trigger occurs when the logic inputs to the logic function cause the function to be TRUE or at your option FALSE at the time the clock input changes state When you use a state trigger you define m The precondition for each logic input channels 1 2 and 3 m The direction of the state change for the clock input channel 4 J H 4 m The Boolean logic function select from clocked AND NAND OR and NOR IS S S S m The condition for triggering whether the trigger occurs when the Boolean function becomes TRUE logic high or FALSE logic low A setup hold trigger occurs when a logic input changes state inside of the setup and hold times relative to the cloc
278. rms 3 144 integral math waveforms 3 165 Area 3 88 Glossary 1 Attenuation Glossary 2 Auto Main Trigger menu 3 59 Automated Measurements Snapshot of 2 23 Automated measurements 2 19 3 87 of derivative math waveforms 3 163 procedure 3 163 of FFT math waveforms 3 150 of integral math waveforms 3 169 Automatic trigger mode 3 51 Glossary 2 Autosave Save Recall Waveform menu 3 116 Autoset 2 14 3 5 3 48 Glossary 2 Default settings 3 6 3 48 How to execute 3 6 3 48 AUTOSET button 2 14 AUX TRIGGER INPUT BNC 2 5 Auxiliary trigger 3 50 Index 1 Index Average Incompatible with InstaVu 3 46 Average acquisition mode 3 20 3 48 Glossary 2 Average mode Acquire menu 3 138 Average Acquire menu 3 23 Average More menu 3 144 Bandwidth Glossary 2 Selecting 3 12 Bandwidth Vertical menu 3 12 Base Cursor menu 3 101 Blackman Harris window 3 148 BMP 3 121 BMP Color Hardcopy menu 3 122 BMP Mono Hardcopy menu 3 122 BNC AUX TRIGGER INPUT 2 5 DELAYED TRIGGER OUTPUT 2 5 MAIN TRIGGER OUTPUT 2 5 SIGNAL OUTPUT 2 5 Bold Color menu 3 34 Burst width 3 88 Button ACQUIRE MENU 3 23 3 138 AUTOSET 2 14 CLEAR MENU 2 3 2 8 2 12 2 20 2 21 3 95 CURSOR 3 99 DELAYED TRIG 3 53 3 83 DISPLAY 3 28 3 33 FORCE TRIG 3 54 HARDCOPY 3 117 3 122 3 131 HELP 3 135 HORIZONTAL MENU 3 53 3 83 InstaVu 3 43 MEASURE 3 90 MORE 3 8 3 115 3 142 ON STBY 1 5
279. rshoot Negative width A timing measurement of the distance time between two amplitude points falling edge MidRef default 50 and rising edge MidRef default 50 on a negative pulse Normal trigger mode A mode on which the oscilloscope does not acquire a waveform record unless a valid trigger event occurs It waits for a valid trigger event before acquiring waveform data NOR A logic Boolean function in which the output of the OR function is complemented true becomes false and false becomes true On the oscilloscope that is a trigger logic pattern and state function OR A logic Boolean function in which the output is true if any of the inputs are true Otherwise the output is false On the oscilloscope that is a trigger logic pattern and state function Oscilloscope An instrument for making a graph of two factors These are typically voltage versus time Peak Detect acquisition mode TDS 700A Models Only A mode in which the oscilloscope saves the minimum and maximum samples over two adjacent acquisition intervals For many glitch free signals that mode is indistinguishable from the sample mode Peak detect mode works with real time non interpolation sampling only Peak to Peak Amplitude voltage measurement of the absolute difference between the maximum and minimum amplitude Period A timing measurement of the time covered by one complete signal cycle It is the reciprocal of frequency and is measured i
280. s Table 1 1 Key Features of the TDS Oscilloscopes TDS 684A TDS 744A TDS 784A 5 GS s on each chan nel simultaneously 1GHz 2 GS s 4 GS s 500 MHz 1 GHz Channels Record lengths maxi mum Acquisition modes Four each with 8 bit resolution 15 K samples per channel Sample envelope and average Up to 50 K standard up to 250 K 2 channels and 500 K 1 channel with Option 1M Sample envelope average high resolution and peak detect InstaVu mode which updates the display at rates rivaling the fastest analog oscilloscopes Display le Color Zoom which allows you to magnify a waveform Color Dual Window Zoom which shows a waveform magnified and unmagnified on the same display TDS 684A TDS 744A amp TDS 784A User Manual Product Description Product Specification Table 1 1 Key Features of the TDS Oscilloscopes Cont TDS 684A TDS 744A TDS 784A Include edge logic and pulse Video trigger with option 05 modes include NTSC SECAM PAL HDTV and F lexF ormat 1 44 Mbyte 3 5 inch DOS 3 3 or later floppy disk NVRAM storage for saving waveforms hardcopies and setups Feature Trigger modes Storage Full GPIB programmability Hardcopy output using GPIB RS 232 or Centronics ports The product specification is found in the technical reference TDS 684A TDS 744A amp TDS 784A Performance
281. s between actual acquired samples by using a straight line fit It assumes all the interpolated points fall in their appropriate point in time on that straight line Linear interpolation is useful for many waveforms such as pulse trains Sin x x interpolation computes record points using a curve fit between the actual values acquired It assumes all the interpolated points fall along that curve That is particularly useful when acquiring more rounded waveforms such as sine waves Actually it is appropriate for general use although it may introduce some overshoot or undershoot in signals with fast rise times NOTE When using either type of interpolation you may want to set the display Style so that the real samples are displayed intensified relative to the interpolated samples The instructions under Select the Display Style on page 3 28 explain how to turn on intensified samples Interleaving A TDS 700A Oscilloscope can interleave its channels to attain higher digitizing rates without equivalent time sampling or interpolating The oscilloscope applies the digitizing resources of unused channels that is channels that are turned off to sample those that are in use turned on Table 3 2 lists how interleaving more than one digitizer to sample a channel extends the maximum digitizing rate Table 3 2 How Interleaving Affects Sample Rate Maximum Digitizing Rate TDS 744A TDS 784A Four 2 Gs second 4 Gs second Two Two
282. s the same button or use the general purpose knob until diff appears in the menu label 6 Press OK Create Math Wfm side to display the derivative of the waveform you input in step 1 You should now have your derivative math waveform on screen Use the Vertical SCALE and POSITION knobs to size and position your waveform as you require TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications Derivative Math Waveform Source Waveform To Take Automated Measurements To Take Cursor Measurements Tek Run 5 00MS s Sample chi 20 0mva o AOR 200kVss Mathi Math2 Math3 FFFCCh1 inv chi 10 ous Ref1 M 10 0 chi ov Math Change Math waveform definition No Extended Processing Average 2 Oooo o Ref2 Ref3 Ref4 C c Saks Figure 3 95 Derivative Math Waveform Once you have displayed your derivative math waveform you can use automated measurements to make various parameter measurements Do the following steps to display automated measurements of the waveform 1 Be sure MORE is selected in the channel selection buttons and that the differentiated math waveform is selected in the More main menu 2 Press MEASURE gt Select Measrmnt main 3 Select up to four measurements in the si
283. s3 are TRUE then the oscilloscope triggers NAND af 1 Clocked NAND If not all of the preconditions selected ae for the logic inputs are TRUE then the oscilloscope triggers OR a gt Clocked OR If any of the preconditions selected for e the logic inputs are TRUE then the oscilloscope triggers 7 NOR 3 1 Clocked NOR If none of the preconditions selected for y the logic inputs3 are TRUE then the oscilloscope triggers 7 1 Note that for state class triggers the definition must be met at the time the clock input changes state 2 The definitions given here are correct for the Goes TRUE setting in the Trigger When menu If that menu is set to Goes False swap the definition for AND with that for NAND and for OR with NOR for both pattern and state classes 3 The logic inputs are channels 1 2 3 and 4 when using pattern logic triggers For State Logic Triggers channel 4 becomes the clock input leaving the remaining channels as logic inputs Setup hold triggering uses the setup and hold times to define a setup hold violation zone relative to the clock Data that changes state within this zone triggers the oscilloscope Figure 3 38 shows how the setup and hold times you choose positions this zone relative to the clock Setup hold triggering uses the setup hold violation zone to detect when data is unstable too near the time it is clocked Each time trigger holdoff e
284. scilloscope creates either an image or a plot Images are direct bit map representations of the oscilloscope display Plots are vector plotted representations of the display Some formats particularly Interleaf EPS TIFF PCX BMP and HPGL are compatible with various desktop publishing packages Such compatibility means you can paste files created from the oscilloscope directly into a document on any of those desktop publishing systems EPS Mono and Color formats are compatible with Tektronix Phaser Color Printers HPGL is compatible with the Tektronix HC100 Plotter and Epson is compatible with the Tektronix HC200 Printer TDS 684A TDS 744A amp TDS 784A User Manual 3 121 Saving Waveforms and Setups To Set Up for Making Before you make a hardcopy you need to set up communications and hardcopy Hardcopies parameters Do the following procedures to set up for making hardcopies Set Communications Parameters To set up the communication parameters for a printer attached directly to the oscilloscope GPIB RS 232 or Centronics port Press SHIFT UTILITY gt System main gt I O pop up gt Confi gure main gt Hardcopy Talk Only side See Figure 3 70 E Tek Run 2 50MS s Sample RS232 Baud Rate 9600 R 32 HW Setup Eiu Rate Stop Bits Parity None Hard Flagging es ON OII o mi pec 1 1 domy M40 ous chi ff 78mv 3 l GPIB 4 Eas C
285. se Ref amp Panel Memory 3 113 Tek Secure Erase Memory 3 113 Utility menu 3 122 Configure 3 122 3 131 GPIB 3 131 Hardcopy 3 131 Hardcopy Talk Only 3 122 T O 3 122 Off Bus 3 131 Port 3 131 System 3 122 Talk Listen Address 3 131 V V Limit Acquire menu 3 139 Variable Persistence Display menu 3 28 Vectors 3 28 Vectors display Incompatible with InstaVu 3 46 Vectors Display menu 3 28 Vertical Bar cursors 3 97 Glossary 10 Offset 3 13 Position 3 10 3 48 Readout 3 10 Scale 3 10 SCALE knob 2 13 3 10 System 2 13 Vertical Menu Cal Probe 3 104 Vertical menu 20 MHz 3 12 250 MHz 3 12 Bandwidth 3 12 Coupling 3 12 Fine Scale 3 12 Full 3 12 Offset 3 13 Position 3 12 Set to Zero 3 12 VERTICAL MENU button 2 17 Vertical position for DC correction of FFTs 3 153 Vertical POSITION knob 3 10 3 38 Vertical Readout 3 10 Index 14 Vertical SCALE knob 3 10 3 38 VGA Output 2 5 Video Line Number Cursor menu 3 101 Video Trigger Option 5 A 1 Video trigger 3 51 View Palette Color menu 3 34 W Waveform Glossary 10 Acquiring and Displaying of 3 3 Autoset on 3 5 3 48 Coupling to the oscilloscope 3 3 Interval Glossary 11 Math 3 142 3 170 Measuring 3 87 Priority for turning off 3 9 Save Formats 3 115 Saving 3 111 Triggering on 3 49 Waveform clipping See Clipping Waveform differentiation 3 161 Wavef
286. set may change vertical position in order to position the waveform appropriately It always sets vertical offset to O V Table 3 1 lists the autoset defaults Table 3 1 Autoset Defaults Control Selected channel Acquire Mode Acquire Repetitive Signal TDS 700A Models Only Changed by Autoset to Numerically lowest of the displayed channels Sample On Acquire Stop After RUN STOP button only Display Style Vectors Display Intensity Overall If less than 50 set to 75 Display Format YT FastFrame TDS 700A Off Models Only Horizontal Position Centered within the graticule window Horizontal Scale As determined by the signal frequency Horizontal Time Base Main Only Horizontal Record Length Unchanged Horizontal Lock Unchanged InstaVu Acquisitions Unchanged TDS 700A Models Only Limit Test Off TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms Table 3 1 Autoset Defaults Cont Control Changed by Autoset to Trigger Position Unchanged Trigger Type Edge Trigger Source Numerically lowest of the displayed channels the selected channel Trigger Level Midpoint of data for the trigger source Trigger Slope Positive Trigger Coupling DC Trigger Holdoff Default Holdoff Set equal to 5 horizontal divisions Adjustable Holdoff 250 ns Selection in Mode and Holdoff menu determines whether the default holdoff value or the adjustable hol
287. set the cursor to the selection The oscilloscope deletes directories recursively That means it deletes both the directories and all their contents Z Tek Run 1 00GS 5 Sample Use amp to choose J EQ 7 gt E Press SELECT to change G F File Directory fd0 Free 690KB Utilities 0 WFMS E 94 03 17 08 15 58 TEK TEKOOOO3 WFM 94 03 08 12 40 46 SETHLD1 SET 94 03 17 06 53 56 TEKO0001 SET E 94 03 17 06 56 14 TEK00002 5ET E 94 03 17 06 56 32 Rename TEK00000 WFM 94 03 17 06 57 18 TEKO0001 WFM E 94 03 17 06 57 34 Delete more 1of2 eca ave eca File saved Current Factory utilities Setup Setup Setup LOJO C C O DIGIC IC C O Figure 3 68 File Utilities To Rename To rename a file or directory turn the general purpose knob until it scrolls the cursor over the name of the file or directory to delete For example to rename Then press the side menu Rename button See Figure 3 69 The labeling menu should appear Turn the general purpose knob or use the main menu arrow keys to select each letter Press Enter Char from the main 3 118 TDS 684A TDS 744A amp TDS 784A User Manual Saving Waveforms and Setups menu to enter each letter When you have entered the name press the side menu OK Accept item Va Tek Run 100kKS 5 Sample Enter Label
288. signals over many repetitions of the event The TDS 744A and TDS 784A Oscilloscopes use a type of equivalent time sampling called random equivalent time sampling It utilizes an internal clock that runs asynchronously with respect to the input signal and the signal trigger The oscilloscope takes samples continuously independent of the trigger position and displays them based on the time difference between the sample and the trigger Although the samples are taken sequentially in time they are random with respect to the trigger TDS 684A TDS 744A amp TDS 784A User Manual Glossary 3 Glossary GND Glossary 4 Fall time A measurement of the time it takes for the trailing edge of a pulse to fall from a HighRef value typically 90 to a LowRef value typically 10 of its amplitude Frequency A timing measurement that is the reciprocal of the period Measured in Hertz Hz where 1 Hz 1 cycle per second Gated Measurements A feature that lets you limit automated measurements to a specified portion of the waveform You define the area of interest using the vertical cursors General purpose knob The large front panel knob with an indentation You can use it to change the value of the assigned parameter Glitch positive trigger Triggering occurs if the oscilloscope detects positive spike widths less than the specified glitch time Glitch negative trig
289. sing repeatedly Color in the side menu 3 If you want to use the factory default for this color press the side menu Reset to Factory Color 4 Choose Hue from the side menu and use the general purpose knob or keypad to select the desired hue Values range from 0 to 359 Sample values are 0 blue 60 magenta 120 red 180 yellow 240 green and 300 cyan 5 Choose Lightness from the side menu and use the general purpose knob or keypad to select the lightness you desire A value of 0 results in black A value of 50 provides the nominal color A value of 100 results in white TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms 6 Choose Saturation from the side menu and use the general purpose knob or keypad to select the saturation you desire A value of 100 provides a pure color A value of 0 provides gray ve Tek Run 250kS 5 Sample Change Colors Color Ch Hue o Chi Ch2 Ch3 Ch4 Math Ref Clsn Saturation o a eee Somy esate zone Grat Text Scroll ScrTxt Color Eog Palette errr Wap Wap Restore Settings gt Math Reference Options lt Colors Normal Colors Colors Colors Colors a Lightness 65 OII oj Figure 3 20 Display Menu Palette Colors Set Math Waveform Color To define math waveform colors 1 Choose to define math waveform
290. sired channel or reference waveform Tek Run 100kKS 5 Sample Math Change Math waveform definition No Extended S Processing Average 2 chi 100mV M 500Ms Chi Oooo Math2 Math3 Chivche FFTCChI inv ch MIP CIO C C CO Figure 3 84 More Menu 3 142 TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications 3 Press Set Function to side repeatedly to cycle it to inv invert intg or diff Waveform integration intg is described on page 3 165 and waveform differentiation diff is described on page 3 161 4 To create the math waveform press OK Create Math Wfm side To Use Dual Wim Math To create a math waveform that requires two waveform sources do the following steps 1 Press MORE gt Math Math2 or Math3 main gt Change Math waveform definition side gt Dual Wfm Math main 2 To define the first source waveform press Set 1st Source to side repeated ly to cycle it to the desired channel or reference waveform 3 To define the second source waveform press Set 2nd Source to side repeatedly to cycle it to the desired channel or reference waveform 4 To enter the math operator press Set operator to side repeatedly to cycle it through the choices Supported operators are and NOTE If you select for m
291. slew rate triggers when Changed by Factory Init to Trig if faster than 1 80 V 800 mV Trig if faster than Pulse slew rate setting Pulse trigger class Pulse trigger level Glitch 0 0V Pulse trigger source Glitch runt width and slew rate Channel 1 Ch 1 Pulse width lower limit 2 0 ns Pulse width trigger polarity Positive Pulse width trigger when Within limits Pulse width upper limit 2 0 ns Repetitive signal TDS 700A models only On RS 232 parameters No change Saved setups No change Saved waveforms No change Stop after R S button Vertical bandwidth all channels Full Vertical coupling all channels DC Vertical impedance termination 1MQ all channels Vertical offset all channels OV Vertical position all channels 0 divs Vertical volts division all channels 100 mV division Zoom horizontal all channels 1 0X TDS 684A 2 0X TDS 700A models Zoom horizontal lock Zoom horizontal position all channels Zoom mode DZ Dual Zoom Offset TDS 700A models only All 50 0 5 the middle of the display Off Minimum Available Dual Window Zoom Selected Graticule TDS 700A models only Zoom vertical all channels Zoom vertical position all channels Upper 1 0X TDS 684A 2 0X TDS 700A models 0 divisions TDS 684A TDS 744A amp TDS 784A User Manual D 5 Appendix D Factory Initialization Settings D 6 TDS 684A TDS 744
292. spect to the input signal and the signal trigger The oscilloscope takes samples independently of the trigger position and displays them based on the time difference between the sample and the trigger Your oscilloscope can interpolate between the samples it acquires Like for equivalent time sampling it does so only when it cannot obtain all the real samples it needs to fill up its waveform record For instance setting the horizontal SCALE to progressively faster acquisition rates leaves progressively shorter time periods for the waveform record Therefore the oscilloscope must sample faster to acquire the samples record points needed to fill up the record TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms Eventually the time period established by scale setting does not allow enough time to get all the real samples needed to fill the record The situation just described occurs if you set the Horizontal SCALE knob to a time base setting that is faster than 10 ns TDS 684A The setting varies with the number of channels for TDS 700A models see Tables 3 4 and 3 5 begin ning on page 3 24 The oscilloscope then interpolates to create the intervening points in the waveform record There are two options for interpolation linear or sin x x TDS 700A models can also equivalent time sample to acquire more samples see Equivalent Time Sampling on page 3 18 Linear interpolation computes record point
293. ss you position the source waveform off screen so it is clipped m When using the vertical scale knob to scale the source waveform note that it also scales your integral waveform The source waveforms that you connect to the oscilloscope often have a DC offset component The oscilloscope integrates this offset along with the time varying portions of your waveform Even a few divisions of offset in the source waveform may be enough to ensure that the integral waveform saturates clips especially with long record lengths You may be able to avoid saturating your integral waveform if you choose a shorter record length Press HORIZONTAL MENU gt Record Length main Reducing the sample rate use the HORIZONTAL SCALE knob with the source channel selected might also prevent clipping You can also select AC coupling in the vertical menu of the source waveform or otherwise DC filter it before applying it to the oscilloscope input Once you have your waveform optimally displayed you may magnify or reduce it vertically and horizontally to inspect any feature you desire Just be sure the integrated waveform is the selected waveform Press MORE then select the integrated waveform in the More main menu Then use the Vertical and Horizontal SCALE knobs to adjust the math waveform size TDS 684A TDS 744A amp TDS 784A User Manual 3 169 Using Features for Advanced Applications If you wish to see the zoom factor 2X 5X etc you need
294. ssary 6 Glossary 8 TDS 684A TDS 744A amp TDS 784A User Manual Index E Edge trigger 3 50 3 57 Glossary 3 How to set up 3 58 3 86 Readout 3 57 Edge Main Trigger menu 3 57 3 58 Edges Measure Delay menu 3 95 Either Main Trigger menu 3 73 3 74 3 77 empty Saved waveform status 3 114 Encapsulated Postscript 3 121 Enter Char Labelling menu 3 118 3 119 Envelope Incompatible with InstaVu 3 46 Envelope acquisition mode 3 20 3 48 Glossary 3 Envelope Acquire menu 3 23 EPS Color Img Hardcopy menu 3 122 EPS Color Plt Hardcopy menu 3 122 EPS Mono Img Hardcopy menu 3 122 EPS Mono Plt Hardcopy menu 3 122 Epson 3 121 Epson Hardcopy menu 3 122 Equivalent time sampling 3 18 3 48 Equivalent time sampling random Glossary 3 F Factory initialization settings D 1 D 6 Factory Setup How to execute 3 7 3 48 factory Saved setup status 3 111 Fall time 3 88 Glossary 4 Falling edge Delayed Trigger menu 3 85 Falling edge Main Trigger menu 3 60 3 68 3 69 Fast Fourier Transforms description 3 144 Fast Fourier Transforms FFTs applications 3 144 FastFrame Incompatible with InstaVu 3 45 FastFrame interactions 3 48 3 99 FastFrame Setup Horizontal menu 3 47 FastFrame Horizontal menu 3 47 FFT frequency domain record 3 150 defined 3 15 1 3 152 length of 3 152 FFT math waveform 3 145 acquisition mode 3 154 aliasing 3 155 automated me
295. stance the oscilloscope saves the first waveform you save in the file TEKOO001 WFM the second in TEK00002 WFM and so on TDS 684A TDS 744A amp TDS 784A User Manual Saving Waveforms and Setups To Change Format TDS 700A Models Only To select the format that the oscilloscope uses to save TDS 700A Models waveforms to a disk press save recall WAVEFORM gt Save Format main gt Internal MathCad or Spreadsheet side Internal creates files WFM in the internal format of the oscilloscope MathCad creates files DAT in a format usable by MathCad Spreadsheet creates files CSV in a format usable by spreadsheets Excel Lotus 1 2 3 and Quattro Pro To Delete Waveforms To delete a reference waveform s that you no longer need Press SAVE RECALL WAVEFORM gt Delete Refs main gt Delete Ref1 Delete Ref2 Delete Ref3 Delete Ref4 or Delete All Refs side To Delete All Waveforms To remove all stored reference waveforms and setups use the feature called Tek and Setups Secure See To Delete All Setups and Waveforms on page 3 113 a Tek Run 100kKS 5 Sample Save Waveform To File To Refl empty To Ref2 empty To Ref3 empty To Ref4 20 0mv TO M 500s Chi 26 8mV Recall wim EAT Delete sutosave File to Ref Refs Single seq Utilities MID ClO S C O OIIO o Figure 3 66 Save Wav
296. t Logic pop up gt Class main gt Pattern pop up gt Set Thresholds main gt Ch1 Ch2 Ch3 or Ch side 2 Use the MAIN TRIGGER LEVEL knob the general purpose knob or the keypad to set each threshold TDS 684A TDS 744A amp TDS 784A User Manual 3 65 Triggering on Waveforms To Define a Time Qualified 3 66 Pattern Trigger To Define the Logic To choose the logic function you want applied to the input channels see page 3 61 for definitions of the logic functions for both pattern and state triggers Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt Pattern pop up gt Define Logic main gt AND OR NAND or NOR side Set Trigger When To choose to trigger when the logic condition is met Goes TRUE or when the logic condition is not met Goes FALSE do the following step Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt Pattern pop up gt Trigger When main gt Goes TRUE or Goes FALSE side The side menu items TRUE for less than and TRUE for greater than are used to time qualify a pattern trigger See the procedure Define a Time Qualified Pattern Trigger that follows for instructions To Set Mode and Holdoff Mode and holdoff can be set for all standard trigger types and classes To set mode and holdoff refer to To Set Mode amp Holdoff on page 3 59 To learn more about trigger mode and holdoff see the descriptions Trigger Mo
297. t The area over one waveform cycle For data not cyclical you might prefer to use the Area measurement If StartCycle EndCycle then return the interpolated value at StartCycle EndCycle een Waveform t dt StartCycle For details of the integration algorithm see page B 12 Timing measurement The duration of a burst 1 Find MCross1 on the waveform This is MCrossStart 2 Find the last MCross begin the search at EndCycle and search toward StartCycle This is MCrossStop This could be a different value from MCross1 3 Compute BurstWidth MCrossStop MCrossStart TDS 684A TDS 744A amp TDS 784A User Manual B 5 Appendix B Algorithms Cycle Mean Cycle RMS Delay Fall Time c Amplitude voltage measurement The mean over one waveform cycle For non cyclical data you might prefer to use the Mean measurement If StartCycle EndCycle then return the interpolated value at StartCycle EndCycle Waveform t dt Si tartCycle CycleMean EndCycle StartCycle x Sampleinterval For details of the integration algorithm see page B 12 The true Root Mean Square voltage over one cycle If StartCycle EndCycle then CycleRMS Waveform Start Otherwise EndCycle Waveform t dt Si tartCycle EndCycle StartCycle x SampleInterval CycleRMS For details of the integration algorithm see page B 12 Timing measurement The amount of time between the MidRef and
298. t the record length desired from the side menu Press more to see additional choices The available record lengths are as follows m The TDS 684A Oscilloscope provides record lengths of 500 1000 2500 5000 and 15000 points m The TDS 700A Oscilloscopes provide record lengths of 500 1 000 2 500 5 000 15 000 and 50 000 plus with option 1M 75 000 100 000 130 000 250 000 and 500 000 Option 1M is available only at the time of original purchase and is not available for the TDS 684A NOTE TDS 700A Models Hi Res acquisition mode requires twice the acquisition memory of other acquisition modes therefore the maximum record length available is 15 000 points for TDS 700A Oscilloscopes without option 1M and 50 000 points with option 1M Turning Hi Res on switches the setting for record length accordingly thereby keeping the oscilloscope from running out of memory 2 To fit an acquired waveform to the visible screen regardless of record length press HORIZONTAL MENU gt Record Length main Then toggle Fit to Screen to ON from the side menu This feature fits the waveform automatically much like you could do manually by turning zoom mode on and changing the time division until the waveform fits the screen To turn off this feature toggle Fit to Screen to OFF Horizontal Scale To change the horizontal scale time per division numerically in the menu instead of using the Horizontal SCALE knob Press HORIZONTAL MENU gt
299. tFrame parameters Frame Length refers to the number of samples in each acquisition Frame count refers to the number of acquisitions to store in the acquisition memory of the channel The oscilloscope will set the record length to a value greater than or equal to the product of the frame count and the frame length If the product exceeds the maximum available record length the oscilloscope will reduce the frame length or frame count in size such that the product will fit the record length Press Horiz Pos main then Frame side and use the general purpose knob to enter the number of a specific frame to view After you press Enter that frame should appear on the display Tek Run 50 0MS s Sampie REI Frame Length 100 E FastFrame Setup FastFrame a ON Frame a erin h sheni 4 Frame count 5 oomvay Tomi oous chis 4oamv PPsOn i 3 p 3 Time Base trigger f i Hp Horiz eens 5 Position Era Main See tay Gdi Pos Setup LOJO C C O PIC IPO C Figure 3 29 Horizontal Menu FastFrame Setup If you shift the waveform right or left with the front panel HORIZONTAL POSITION knob the window next to the side menu Frame button will indicate the frame number of the waveform at the center of the screen TDS 684A TDS 744A amp TDS 784A User Manual 3 47 Acquiring and Displaying Waveforms
300. ted Failures Do Not Immerse in Liquids To prevent product overheating provide proper ventilation If you suspect there is damage to this product have it inspected by qualified service personnel Clean the probe using only a damp cloth Refer to cleaning instructions Safety Terms and Symbols Terms in This Manual A A Terms on the Product These terms may appear in this manual WARNING Warning statements identify conditions or practices that could result in injury or loss of life CAUTION Caution statements identify conditions or practices that could result in damage to this product or other property These terms may appear on the product DANGER indicates an injury hazard immediately accessible as you read the marking WARNING indicates an injury hazard not immediately accessible as you read the marking CAUTION indicates a hazard to property including the product TDS 684A TDS 744A amp TDS 784A User Manual General Safety Summary Symbols on the Product The following symbols may appear on the product 4 A o DANGER Protective Ground ATTENTION Double High Voltage Earth Terminal Refer to Insulated Manual Certifications and Compliances CSA Certified Power CSA Certification includes the products and power cords appropriate for use in Cords the North America power network All other power cords supplied are approved for the country of use TDS 684A TDS 744A amp TDS 784A User
301. ted by f where W t dt W t dt A A W t is the sampled waveform W t is the continuous function obtained by linear interpolation of W t A and B are numbers between 0 0 and RecordLength 1 0 If A and B are integers then B Belgii i woa sx 570r Mes A i A where s is the sample interval Similarly is approximated by 2 where WO at W t dt A W t is the sampled waveform W t is the continuous function obtained by linear interpolation of W t A and B are numbers between 0 0 and RecordLength 1 0 If A and B are integers then i A 2 A 2 B 1 Rey f i WO dt s x py O UA ee where s is the sample interval Measurements on Envelope Waveforms Time measurements on envelope waveforms must be treated differently from time measurements on other waveforms because envelope waveforms contain so many apparent crossings Unless otherwise noted envelope waveforms use either the minima or the maxima but not both determined in the following manner 1 Step through the waveform from Start to End until the sample min and max pair DO NOT straddle MidRef 2 If the pair gt MidRef use the minima else use maxima TDS 684A TDS 744A amp TDS 784A User Manual Appendix B Algorithms If all pairs straddle MidRef use maxima See Figure B 4 The Burst Width measurement always uses both maxima and minima to determine crossings MidR ef Both min and max samples are abo
302. template you create in a different destination from that just stored To view the template you have created press the MORE button Then press the button corresponding to the destination reference memory you have used The waveform appears on the display TDS 684A TDS 744A amp TDS 784A User Manual 3 139 Using Features for Advanced Applications To Select a Limit Test Source To Specify the Limit Test 3 140 Response NOTE To view the waveform data as well as the template envelope it might be useful to select the Dots display style See Select the Display Style on page 3 28 Now specify the channel that will acquire the waveforms to be compared against the template you have created 1 Press SHIFT ACQUIRE MENU gt Limit Test Sources main gt Compare Ch1 to Compare Ch2 to Compare Ch3 to Compare Ch4 to Compare Math1 to Compare Math2 to or Compare Math3 to side 2 Once you have selected one of the four channels or a math waveform as a waveform source from the side menu press the same side menu button to select one of the reference memories in which you have stored a template Valid selections are any of the four reference waveforms Ref1 through Ref4 or None Choosing None turns limit testing off for the specified channel or math waveform NOTE Specify the same reference memory you chose as the template destination if you wish to use the template you just created If you have created more than
303. th video waveforms see the TDS Family Option 05 Video Trigger Interface if your oscilloscope is equipped with the video trigger option Taking Graticule Measurements The TDS Oscilloscope provides a graticule for measuring the difference either in time or amplitude between two points on a waveform record Graticule measurements provide you with quick visual estimates For example you might look at a waveform amplitude and say it is a little more than 100 mV This section briefly describes how to take graticule measurements TDS 684A TDS 744A amp TDS 784A User Manual 3 101 Measuring Waveforms Measure Waveform Amplitude Measure Waveform Time To measure the amplitude of a waveform do the following steps 1 Press the channel selection button of the channel you wish to measure Note the vertical scale factor for the channel in the channel readout on screen 2 Count the graticule divisions between two features to be measured and multiply by the vertical scale factor For example if you count five major vertical graticule divisions between the minimum and maximum values of a waveform at a scale factor of 100 mV di vision then you can easily calculate your peak to peak voltage as 5 divisions x 100 mV division 500 mV NOTE When you select the NTSC graticule the volts per division of all selected channels is set to 143 mV div 152 mV div for PAL where the divisions are those of the conventional graticule
304. the point See Choose a Palette on page 3 33 Infinite Persistence style accumulates the record points until you change some control such as scale factor causing the display to be erased TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms NOTE TDS 700A models only See Using InstaVu Acquisition Mode on page 3 43 for differences in how Style setup differs for InstaVu mode Tek Run 100kS 5 Hi Res Display Style 7 m vectors Dots Intensified Samples Infinite Persistence 20 omv C M 500ys Chif 26 4mv gwarable f f 5e0ms Style 5 Readout Filter Graticule ngs Intensity options Sim x x Full DIGIC IC lO O r Figure 3 17 Display Menu Style Adjust Intensity Intensity lets you set text graticule and waveform intensity brightness levels To set the intensity Press DISPLAY Intensity main gt Text Grat or Waveform side Enter the intensity percentage values with the keypad or the general purpose knob All intensity adjustments operate over a range from 20 close to fully off to 100 fully bright Set Display Readout Readout options control whether the trigger indicator trigger level bar and Options current date and time appear on the display The options also control what style trigger level bar long or short is displayed
305. threshold levels in 600 ps or less Also to reliably slew rate trigger a pulse must have a width of 7 5 ns or more A pulse of less width may trigger on the wrong slope or not trigger at all Switch to edge triggering and check the pulse width if you can t slew rate trigger as expected iL Slew Rate Trigger When Cursors Measure Slew Rate Components of Pulse Edge dv and dt Trigger Bar at Upper Threshold Trig if Slower Than MW Delta Time Trigger Point at Second Crossing Slew Rate 16 0mMVZns Trigger Bar at Lower Threshold elelelel 1 00 YQ loons Slew chi PEA H ger oF x ade A We Source Polarity chi f Class lt Slew gt Figure 3 46 Main Trigger Menu Slew Rate Class TDS 684A TDS 744A amp TDS 784A User Manual 3 79 Triggering on Waveforms Delayed Triggering 3 80 To understand what happens when you slew rate trigger study Figure 3 46 as you consider the following points The main menu shows the oscilloscope is set to trigger based on the slew rate of a pulse input to the trigger source Ch 1 It is set to monitor the positive polarity pulse edges of the trigger source and to trigger on any edge with a slew rate faster than the slew rate setting The Trigger When side menu displays the readout Slew Rate that indicates the slew rate setting
306. time and the number of events Hint You can go directly to the Delayed Trigger menu See step 6 By selecting one of Triggerable After Time Events or Events Time the oscilloscope automatically switches to Delayed Triggerable in the Horizontal TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms menu You will still need to display the Horizontal menu if you wish to leave Delayed Triggerable The Source menu lets you select which input will be the delayed trigger source 8 Press Source main gt Ch1 Ch2 Ch3 Ch4 or DC Aux side NOTE Selecting DC Aux as source in BOTH the main and delayed triggering menus forces main and delayed trigger levels to adjust in tandem As long as their source remain DC Aux adjusting the trigger level for either system adjusts it for both systems 9 Press Coupling main gt Main Trigger DC or Noise Rej side to define how the input signal will be coupled to the delayed trigger Main Trigger sets delayed trigger coupling to match the main trigger coupling setting For descriptions of the DC and Noise Rej coupling types see To Specify Coupling on page 3 58 10 Press Slope main to select the slope that the delayed trigger will occur on Choose between the rising edge and falling edge slopes When using Delayed Triggerable mode to acquire waveforms two trigger bars are displayed One trigger bar indicates the level set by the main trigger system the other
307. ting of its current control settings on screen Or you may find it handy to display operating information about front panel controls and menus instead of looking them up in this manual The following topic tells you how to do both m Determining Status and Accessing Help The topics just listed contain steps that you perform to accomplish the task that the topic defines You should read Conventions on page xiv of Preface before reading about these tasks Each topic just listed comprises more basic operation tasks and topics A list of these tasks follows Coupling Waveforms to the Oscilloscope 0000 eee eee 3 3 Setting up Automatically Autoset and Reset 005 3 5 Selecting Channels ccros edo Poet load pales web e a weet a aenlt ace hs eet 3 7 Scaling and Positioning Waveforms 0 cece eee eens 3 9 Choosing an Acquisition Mode 2 0 e cece eens 3 16 Customizing the Display 0 0 ccc eens 3 27 Customizing the Display Color 0 cece cee eee ee 3 33 TDS 684A TDS 744A amp TDS 784A User Manual 3 1 Overview Triggering on Waveforms Measuring Waveforms Saving Waveforms and Setups Determining Status and Accessing Help Using Features for Advanced Applications Zooming on Waveforms 0 cee eee eee eee ene nee 3 37 Using InstaVu Acquisition Mode TDS 700A Models Only 3 43 Using FastFrame TDS 700A Models Only
308. tion see Reference A list of the topics covered begins on Page 3 1 TDS 684A TDS 744A amp TDS 784A User Manual 2 1 Overview 2 2 TDS 684A TDS 744A amp TDS 784A User Manual D Operating Interface Maps This section contains illustrations or maps of the display the front and rear panels and the menu system of the TDS Oscilloscope These maps will help you understand and operate the oscilloscope This section also contains a visual guide to using the menu system Front Panel Map Left Side Tektronix TDS 684A siitandoscititscore 58s File System page 3 117 Side Menu Buttons page 2 7 ON N CLEAR MENU w J a Clo H Removes Menus CLEAR from the Display MENU ON STBY Switch Main Menu Buttons page 1 5 page 2 7 TDS 684A TDS 744A amp TDS 784A User Manual 2 3 Operating Interface Maps Front Panel Map Right Side Measurement System page 3 87 Cursor Measurements page 3 97 Saving and Recalling Waveforms page 3 114 File System page 3 117 Hardcopy page 3 120 File System page 3 117 Acquisition Modes page 3 20 APPLICATION SAVE RECALL MEASURE WAVEFORM Autoset page 3 5 STATUS HELP SETUP Help page 3 135 Status page 3 133 Saving and Recalling Setups page 3 111 Selecting Channels page 3 7 Waveform Math
309. tion your source waveform The vertical position and vertical offset will not affect your derivative waveform unless you position the source waveform off screen so it is clipped m When using the vertical scale knob to scale the source waveform note that it also scales your derivative waveform Because of the method the oscilloscope uses to scale the source waveform before differentiating that waveform the derivative math waveform may be too large vertically to fit on screen even if the source waveform is only a few divisions on screen You can use Zoom to reduce the size of the waveform on screen see Zoom that follows but if your waveform is clipped before zooming it will still be clipped after it is zoomed If your math waveform is a narrow differentiated pulse it may not appear to be clipped when viewed on screen You can detect if your derivative math wave form is clipped by expanding it horizontally using Zoom so you can see the TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications Using Zoom Waveform Integration clipped portion Also the automated measurement Pk Pk will display a clipping error message if turned on see To Take Automated Measurements on page 3 163 If your derivative waveform is clipped try either of the following methods to eliminate clipping m Reduce the size of the source waveform on screen Select the source channel and use the vertical SCALE knob
310. to turn Zoom on press ZOOM gt On side The vertical and horizontal zoom factors appear on screen Whether Zoom is on or off you can press Reset Zoom Factors side to return the zoomed integral waveform to no magnification 3 170 TDS 684A TDS 744A amp TDS 784A User Manual a a Appendix A Options and Accessories Options Table A 1 Options This appendix describes the various options as well as the standard and optional accessories that are available for the TDS Oscilloscope Tektronix will ship the options shown in Table A 1 Option Label Description ee Al Universal European 220 V 50 Hz power cord USS power cord RK A2 UK power cord 240 V 50 Hz power cord A3 Australian power cord 240 V 50 Hz power cord A4 North American power 240 V 60 Hz power cord cord A5 Switzerland power cord 220 V 50 Hz power cord 05 Video trigger Oscilloscope comes with tools for investigating events that occur when a video signal generates a horizontal or vertical 8 a sync pulse It allow investigation of a range of NTSC PAL SECAM and high definition TV signals 1K Scope cart K420 scope cart This cartcan help transport the oscilloscope around many lab environments l 4 TDS 684A TDS 744A amp TDS 784A User Manual Appendix A Options and Accessories Table A 1 Options Cont Option
311. ts div time div and trigger level to produce a coherent and stable waveform display Average acquisition mode In this mode the oscilloscope acquires and displays a waveform that is the averaged result of several acquisitions Averaging reduces the apparent noise The oscilloscope acquires data as in the sample mode and then averages it according to a specified number of averages Bandwidth The highest frequency signal the oscilloscope can acquire with no more than 3 dB x 707 attenuation of the original reference signal Burst width A timing measurement of the duration of a burst Channel One type of input used for signal acquisition The oscilloscope has four channels Channel Reference Indicator The indicator on the left side of the display that points to the position around which the waveform contracts or expands when vertical scale is changed This position is ground when offset is set to 0 V otherwise it is ground plus offset Coupling The association of two or more circuits or systems in such a way that power or information can be transferred from one to the other You can couple the input signal to the trigger and vertical systems several different ways Cursors Paired markers that you can use to make measurements between two waveform locations The oscilloscope displays the values expressed in volts or time of the position of the active cursor and the distance between the two cursors TDS 684A TDS 744A amp TDS
312. tude measurement accuracy in your FFT better amplitude accuracy over frequency resolution or to provide a compromise between both You can choose from these four windows Rectangular Hamming Hanning and Blackman Harris In step 8 page 3 147 in To Create an FFT the four windows are listed in order according to their ability to resolve frequencies versus their ability to accurately measure the amplitude of those frequencies The list indicates that the ability of a given window to resolve a frequency is inversely proportional to its ability to accurately measure the amplitude of that frequency In general then choose a window that can just resolve between the frequencies you want to measure That way you will have the best amplitude accuracy and leakage elimination while still separating the frequencies TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications FFT Window we a FFT Time Domain Record After Windowing FFT Frequency Domain Record Figure 3 93 Windowing the FFT Time Domain Record You can often determine the best window empirically by first using the window with the most frequency resolution rectangular then proceeding toward that window with the least Blackman Harris until the frequencies merge Use the window just before the window that lets the frequencies merge for best compro mise between resolution and amplitude accuracy NOTE If the Hanning window merges the
313. u 3 91 3 95 Rename File Utilities menu 3 118 Repetitive Signal Acquire menu 3 24 Reset How to execute 3 7 3 48 Reset All Mappings To Factory Color menu 3 36 Reset All Palettes To Factory Color menu 3 36 Reset Current Palette To Factory Color menu 3 36 Reset to Factory Color Color menu 3 34 Reset Zoom Factors Zoom menu 3 40 Restore Colors Color menu 3 36 Ring Bell if Condition Met Acquire menu 3 140 Rise time 2 20 3 89 Glossary 9 Rising edge Delayed Trigger menu 3 85 Rising edge Main Trigger menu 3 60 3 68 3 69 RLE Color Hardcopy menu 3 122 RMS 3 89 Glossary 9 RS 232 2 5 RS 232 Port 3 123 3 128 RUN STOP 3 48 RUN STOP Acquire menu 3 26 Index 11 Index Runt trigger 3 71 3 72 Glossary 9 How to set up 3 74 3 86 Runt Main Trigger menu 3 74 3 76 S Sample acquisition mode 3 20 Glossary 9 Sample interval Glossary 9 Sample Rate Maximum 3 19 Sample Acquire menu 3 23 Sampling 3 17 Glossary 9 Sampling and acquisition mode 3 24 Sampling and digitizing 3 16 Saturation Color menu 3 35 Save Setups 3 111 3 132 Save Current Setup Save Recall Setup menu 3 111 Save Format Save Recall Waveform menu 3 115 Save Waveform Save Recall Waveform menu 3 114 Save Recall SETUP button 2 10 3 7 3 111 3 117 Save Recall Setup menu 3 111 factory status 3 111 File Utilities 3 113 Recall Factory Setup 3 113 Recall Saved Setup 3 1
314. u acquisition mode differs from the normal acquisition mode used by digital storage oscilloscopes Note that normal mode follows a capture waveform digitize waveform update waveform memory dis play waveform cycle Normal mode misses short term deviations occurring during the long dead times Typical waveform capture rates are 50 waveforms per second InstaVu mode increases the waveform capture rate to up to 400 000 waveforms per second updating the waveform array many times between displays This very fast frame rate greatly increases the probability that runts glitches and other short term changes will accumulate in waveform memory The oscilloscope then displays the waveform at the normal display rate using variable or infinite persistence You can control how long the waveform persists on screen by selecting variable persistence and setting a decay constant To Use InstaVu Mode To turn on InstaVu mode do either of the two following steps 1 Press the front panel button Insta Vu See Figure 3 27 2 Press DISPLAY gt Mode main Push Mode again to toggle to InstaVu mode See Figure 3 27 To turn InstaVu off press InstaVu Alternatively press DISPLAY gt Mode main and then press Mode again to toggle to Normal mode TDS 684A TDS 744A amp TDS 784A User Manual 3 43 Acquiring and Displaying Waveforms Normal DSO Mode Ist Acquired Waveform Record Next Acquired Waveform Record
315. u cannot retrieve them To use Tek Secure to remove all reference setups and waveforms does not affect mass storage disk Press SHIFT UTILITY System main gt Config pop up gt Tek Secure Erase Memory main gt OK Erase Setup amp Ref Memory side Executing Tek Secure accomplishes the following tasks m Replaces all waveforms in reference memories with zero sample values m Replaces the current front panel setup and all setups stored in setup memory with the factory setup m Calculates the checksums of all waveform memory and setup memory locations to verify successful completion of setup and waveform erasure m Ifthe checksum calculation is unsuccessful displays a warning message if the checksum calculation is successful displays a confirmation message To Run the File Utilities To run file utilities see the Managing the File System on page 3 117 To Find More Information See Example 4 Saving Setups on page 2 24 See Appendix D Factory Initialization Settings on page D 1 TDS 684A TDS 744A amp TDS 784A User Manual 3 113 Saving Waveforms and Setups Saving and Recalling Waveforms To Save a Waveform 3 114 TDS Oscilloscope provides four internal reference memories in any of which you can store a waveform Waveform thus stored are retained even when you turn the oscilloscope off or unplug it The oscilloscope also can save waveforms to floppy disk This subsection describes how to save delete and
316. ue either above or below the midpoint depending on whether it is defining the high or low reference level Since this statistical approach ignores short term aberrations overshoot ringing etc histogram is the best setting for examining pulses Min max uses the highest and lowest values of the waveform record This setting is best for examining waveforms that have no large flat portions at a common value such as sine waves and triangle waves almost any waveform except for pulses Define Reference Levels Once you define the reference levels the oscilloscope will use them for all measurements requiring those levels To set the reference levels do the following steps 1 Press MEASURE gt Reference Levels main gt Set Levels side to choose whether the References are set in relative to High 100 and Low 0 or set explicitly in the units of the selected waveform typically volts See Figure 3 55 Use the general purpose knob or keypad to enter the values is the default selection It is useful for general purpose applications Units helps you set precise values For example if your are measuring specifications on an RS 232 C circuit set the levels precisely to RS 232 C specification voltage values by defining the high and low references in units Tek Run 100kKS 5 Sample Zoomy Remove Measrmnt for Chi Measrmnt Gating OFF M ayes chi T Hig tow Setup Histogram Reference Lev
317. uires data after each trigger event using Sample mode It then averages the record point from the current acquisition with those stored from previous acquisitions TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms Au Single Waveform Acquisition Samples Acquired in Four Acquisition Displayed Waveform Drawn Acquisition Intervals Mode Record Points on CRT Interval 1 2 3 4 Interval 1 2 3 4 Uses first sample in interval Use for fastest acquisition rate This is the default mode CIOJO OCI O X UE J XX DAN P Y Uses highest and lowest samples in ag lt two intervals TDS 700A Models Only Use to reveal aliasing and for glitch detection Provides the benefits of enveloping with the speed of a single acquisition CLOCJO C amp 2 eon J L 8 e s Hi Res o Calculates average of all samples in interval TDS 700A Models Only Use to reduce apparent noise Provides the benefits of averaging with the speed of a single acquisition Au Su Multiple Waveform Acquisitions Acquisition Three Acquisitions from One Source Mode
318. ultiply in step 4 the cursor feature will measure amplitude in the units volts squared VV rather than in volts V Tek Run 100kS 5 Sample Change Math Definition Set ist Source to chi 4 i i Set oe T Ee e EET x D od operator to Set 2nd Source to Ch2 Select the type of Math function to define from the bottom row of bezel buttons Define the new function using the side buttons When you are satisfied with the selections press create Math Wim Press CLEAR MENU to return to the More menu chi without creating a Math waveform a a e OIII Oo Figure 3 85 Dual Waveform Math Main and Side Menus TDS 684A TDS 744A amp TDS 784A User Manual 3 143 Using Features for Advanced Applications 5 Press OK Create Math Wfm side to perform the function To Average a Math You can also select whether or not you wish to average a certain math waveform Waveform to do so perform the following steps 1 Fast Fourier Transforms Press MORE Math Math2 or Math3 main to select the math waveform to be averaged Press Average side and enter a value with the general purpose knob or the keypad Any math operations you select for the waveform are performed on an average of multiple acquisitions To turn off math averaging for the selected math waveform press No Extended Pro
319. up gt Class main gt State pop up gt Trigger When main gt Goes TRUE or Goes FALSE side To Set Mode and Holdoff Mode and holdoff can be set for all standard trigger types and classes To set mode and holdoff refer to To Set Mode amp Holdoff on page 3 59 To learn more about trigger mode and holdoff see the descriptions Trigger Modes and Trigger Holdoff on page 3 51 When you select the logic class Setup Hold the oscilloscope uses one channel as a data channel the factory default setting is Chl another channel as a clock channel default is Ch2 and triggers if the data transitions within the setup or hold time of the clock Pages 3 61 and 3 62 describe how setup hold triggers work To use setup and hold triggering do the following procedures Select Setup Hold Triggering Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt Setup Hold pop up Define the Data Source To select the channel that is to contain the data signal 1 Press TRIGGER MENU gt Type main gt Logic pop up gt Class main gt Setup Hold pop up gt Data Source main 2 Press any one of Ch1 Ch2 Ch3 or Ch4 side Do not select the same channel for both the data and clock sources TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms Define the Clock Source and Edge To select the channel that is to contain the clock signal and the edge to use to clock 1 Press TRIGGER ME
320. up to ten setups It also provides a file system so that you can also save setups to a floppy disk Do the following procedures to learn how to save and then recall a setup NOTE Besides being able to save several complete setups the oscilloscope remembers all the parameter settings when you power it off That feature lets you power on and continue where you left off without having to reconstruct the setup in effect when you powered off the oscilloscope Save a Setup First you need to create an instrument setup you want to save Perform the following steps to create and save a setup that is complex enough that you might prefer not to go through all these steps each time you want that display 1 If you are not continuing from the previous example follow the instructions on page 2 9 under the heading Setting Up for the Examples 2 Press SETUP gt Recall Factory Setup main gt OK Confirm Factory Init side 3 Press AUTOSET 4 Press MEASURE gt Select Measrmnt main gt Frequency side Press the more side menu item if the Frequency selection does not appear in the side menu 5 Press CH 2 gt CLEAR MENU 6 Press SAVE RECALL SETUP Save Current Setup main to display the Setup main menu See Figure 2 18 contain a stored setup or with the label factory if they do not To avoid overwrit ing and losing forever a saved setup choose a setup location labeled factory Setup locations
321. ure 3 42 Triggering on a Setup Hold Time Violation In most cases you will enter positive values for both setup and hold time Positive values set the oscilloscope to trigger if the data source is still settling inside the setup time before the clock or if it switches inside the hold time after the clock You can skew this setup hold violation zone that the setup and hold times form by entering negative values See Figure 3 38 on page 3 63 To Set Mode and Holdoff Mode and holdoff can be set for all standard trigger types and classes To set mode and holdoff refer to To Set Mode amp Holdoff on page 3 59 To learn more about trigger mode and holdoff see the descriptions Trigger Modes and Trigger Holdoff on page 3 51 The TDS Oscilloscope can trigger on glitch or runt pulses or it can trigger based on the width or slew rate of a pulse These capabilities makes the oscilloscope suitable for such tasks as unattended monitoring for and capturing of a power supply glitch or GO NO GO slew rate testing of operational amplifiers This TDS 684A TDS 744A amp TDS 784A User Manual Triggering on Waveforms subsection describes how to use each of the four classes of pulse triggers glitch runt width and slew rate triggering A glitch trigger occurs when the trigger source detects a pulse narrower or wider in width than some specified time It can trigger on glitches of either polarity Or you can set the glitch trigger to reject
322. urement press CLEAR MENU which returns you to the Measure menu Take a Snapshot of Sometimes you may want to see all of the automated measurements on screen at Measurements the same time To do so use Snapshot Snapshot executes all of the single waveform measurements available on the selected waveform once and displays the results The measurements are not continuously updated All of the measurements listed in Table 3 9 on page 3 88 except for Delay and Phase are displayed Delay and Phase are dual waveform measurements and are not available with Snapshot The readout area for a snapshot of measurements is a pop up display that covers about 80 of the graticule area when displayed See Figure 3 57 You can display a snapshot on any channel or ref memory but only one snapshot can be displayed at a time To use Snapshot obtain a stable display of the waveform to be measured pressing AUTOSET may help Then do the following steps 1 Press MEASURE SNAPSHOT main 2 Press either SNAPSHOT main or AGAIN side to take another snapshot NOTE The Snapshot display tells you the channel that the snapshot is being made on 3 Push Remove Measrmnt TDS 684A TDS 744A amp TDS 784A User Manual 3 95 Measuring Waveforms 3 96 Snapshot Display Width 500ps Width 500ps Tek Run 100kKS 5 Sample Snapshot a es i yey ba Again E Snapshot on 4 Period 1 000ms Freq 1 00008kKH2 j
323. uring 3 163 record length of 3 162 Desk Top Publishing 3 121 Hardcopy 3 111 Deskjet 3 121 Deskjet Hardcopy menu 3 122 Differential active probes E 3 Differentiation of a derivative 3 162 waveform 3 161 Index 4 Digitizing Glossary 3 Disk How to save a hardcopy to 3 126 Disk drive 3 117 3 132 Display 2 6 Hardcopy of 3 120 Options 3 27 3 48 Record View 3 56 System Glossary 3 Display T Trigger Point Display menu 3 30 DISPLAY button 3 28 3 33 Display menu 3 28 3 33 Color 3 33 Contrast 3 29 Cross Hair 3 31 Display 3 28 Display T Trigger Point 3 30 Dots 3 28 Dots style 3 140 Filter 3 31 Frame 3 31 Full 3 31 Graticule 3 3 1 348 Grid 3 31 Infinite Persistence 3 28 Intensified Samples 3 28 Intensity 3 29 3 48 Linear interpolation 3 31 NTSC 3 31 Overall 3 29 PAL 3 31 Readout 3 29 3 31 Settings 3 28 3 33 Sin x x interpolation 3 31 Style 3 28 Text Grat 3 29 Trigger Bar 3 30 Variable Persistence 3 28 Vectors 3 28 Waveform 3 29 XY 3 31 YT 3 31 Display Display menu 3 28 Display Status menu 3 133 Dots 3 28 Dots style Display menu 3 140 Dots Display menu 3 28 DPU411 II Hardcopy menu 3 122 DPU412 Hardcopy menu 3 122 Dual Wfm Math More menu 3 143 Dual Window Zoom 3 40 Dual Zoom Zoom menu 3 41 Dual Zoom Offset Zoom menu 3 41 Duty cycle 2 20 Glo
324. uring the amplitude at DC remember that 1 VDC equals 1 Vrms and the display is in dB Record Length Most often you will want to use a short record length because more of the FFT waveform can be seen on screen and long record lengths can slow oscilloscope response However long record lengths lower the noise relative to the signal and increase the frequency resolution for the FFT More important they might be needed to capture the waveform feature you want to include in the FFT To speed up oscilloscope response when using long record lengths you can save your source waveform in a reference memory and perform an FFT on the saved waveform That way the DSP will compute the FFT based on saved static data and will only update if you save a new waveform TDS 684A TDS 744A amp TDS 784A User Manual 3 153 Using Features for Advanced Applications Acquisition Mode Zoom and Interpolation 3 154 Selecting the right acquisition mode can produce less noisy FFTs Set up in Sample Use sample mode until you have set up and turned on your FFT Sample mode can acquire repetitive and nonrepetitive waveforms and does not affect the frequency response of the source waveform Hi Res and Average Reduce Noise If the pulse is repetitive Average mode may be used to reduce noise in the signal at a cost of slower display response Average operates on repetitive waveforms only and averaging does affect the frequency response of the source wavefor
325. values from the cursor readouts m Read the integrated voltage over time between the Xs of both paired cursors in volt seconds from the A readout m Read the integrated voltage over time between the X of the selected cursor and the reference indicator of the math waveform from the readout TDS 684A TDS 744A amp TDS 784A User Manual Using Features for Advanced Applications To Take Automated Measurements Offset Position and Scale DC Offset Using Zoom m Read the time difference between the long vertical bars of the paired cursors from the A readout You can also use automated measurements to measure integral math waveforms Use the same procedure as is found under To Take Automated Measurements on page 3 163 When using that procedure note that your measurements on an integral waveform will be in volt seconds rather than in volts per second as is indicated for the differential waveform measured in the procedure When creating integrated math waveforms from live channel waveforms consider the following topics Note the following requirements for obtaining a good display m You should scale and position the source waveform so it is contained on screen Off screen waveforms may be clipped which will result in errors in the integral waveform m You can use vertical position and vertical offset to position your source waveform The vertical position and vertical offset will not affect your integral waveform unle
326. vanced Applications To Create a Derivative of a 3 162 Waveform Derivative waveforms are used in the measurement of slew rate of amplifiers and in educational applications You can store and display a derivative math waveform in a reference memory then use it as a source for another derivative waveform The result is the second derivative of the waveform that was first differentiated The math waveform derived from the sampled waveform is computed based on the following equation Y Xin41 z x4 Where X is the source waveform Y is the derivative math waveform T is the time between samples Since the resultant math waveform is a derivative waveform its vertical scale is in volts second its horizontal scale is in seconds The source signal is differen tiated over its entire record length therefore the math waveform record length equals that of the source waveform To obtain a derivative math waveform Connect the waveform to the desired channel input and select that channel 2 Adjust the vertical and horizontal scales and trigger the display or press AUTOSET 3 Press MORE gt Math1 Math2 or Math3 main gt Change Math Definition side gt Single Wfm Math main See Figure 3 95 4 Press Set Single Source to side Repeatedly press the same button or use the general purpose knob until the channel source selected in step 1 appears in the menu label 5 Press Set Function to side Repeatedly pres
327. ve MidRef so use minima Both min and max samples are below MidRef so use maxima MidR ef Figure B 4 Choosing Minima or Maxima to Use for Envelope Measurements TDS 684A TDS 744A amp TDS 784A User Manual B 13 Appendix B Algorithms Missing or Out of Range Samples If some samples in the waveform are missing or off scale the measurements will linearly interpolate between known samples to make an appropriate guess as to the sample value Missing samples at the ends of the measurement record will be assumed to have the value of the nearest known sample When samples are out of range the measurement will give a warning to that effect for example CLIPPING if the measurement could change by extending the measurement range slightly The algorithms assume the samples recover from an overdrive condition instantaneously For example if MidRef is set directly then MidRef would not change even if samples were out of range However if MidRef was chosen using the choice from the Set Levels in Units selection of the Measure menu then MidRef could give a CLIPPING warning NOTE When measurements are displayed using Snapshot out of range warnings are NOT available However if you question the validity of any measurement in the snapshot display you can select and display the measurement individually and then check for a warning message TDS 684A TDS 744A amp TDS 784A User Manual
328. veforms to the Oscilloscope 00 00 cee eee eee eee 3 3 Setting up Automatically Autoset and Reset 2 00 00 e eee eee 3 5 Selecting Channels oi 5 00 eee an ede cede ate eet ns fee mete 6 3 7 Scaling and Positioning Waveforms 2 cee eee eee eee ee 3 9 Choosing an Acquisition Mode 0 cee cece eee eee een eee 3 16 Customizing the Display 0 2 ccc cect ete n en eee 3 27 Customizing the Display Color 0 0 cee cece ce eee nee 3 33 Zooming on Waveforms 00 c cect eect e teen neee 3 37 Using InstaVu Acquisition Mode TDS 700A Models Only 3 43 Using FastFrame TDS 700A Models Only 0 00 00 eee eee eee 3 46 Triggering on Waveforms sssssssossossosessseesoesoo 3 49 Triggering Concepts 2 70 arte net eae ee e EE 3 49 Triggering from the Front Panel 00 0 cece cece eee 3 53 Triggering on a Waveform Edge 2 0 eee eee cee een eens 3 57 Triggering Based on Logic 00 cece enn eee 3 60 Trig serine on Pulses cc cn kak ana ARE ae heal hehice RAG wRAM Raa 3 70 TDS 684A TDS 744A amp TDS 784A User Manual i Table of Contents Appendices Glossary Index Delayed Ing serino toot owed Sek b at bh wn ae As ee ed Bhat 3 80 Measuring Waveforms ccccccccsccsccscccescscceces 3 87 Taking Automated Measurements 0 0 0 0 00 e eee eee eee 3 87 Taking Cursor Measurements 0 0 0 0
329. will also remove from the display any automated measurements being made on that waveform TDS 684A TDS 744A amp TDS 784A User Manual Acquiring and Displaying Waveforms Waveform Priority To Find More Information 3 To select a math waveform you have created or a reference waveform you have stored press MORE and select the waveform from the More menu Press WAVEFORM OFF while the MORE button is lit to remove the display of the waveform selected in the More menu When you turn off a waveform the oscilloscope automatically selects the next highest priority waveform Figure 3 4 shows the order of priority 1 CH1 1 MATH1 2 CH2 2 MATH2 3 CH3 3 MATH3 4 CH4 4 REF1 5 REF2 6 REF3 7 REF4 Figure 3 4 Waveform Selection Priority Note Figure 3 4 shows two orders of priority due to the following rules If you are turning off more than one waveform and you start by turning off a channel waveform all channels will be turned off before going to the MORE waveforms If you start by turning off the MORE waveforms all the MORE waveforms will be turned off before going to the channel waveforms If you turn off a channel that is a trigger source it continues to be the trigger source even though the waveform is not displayed To read about selecting reference waveforms see Saving and Recalling Waveforms on page 3 114 To read about selecting and creating math waveforms see Waveform Math on page 3 142 Scaling and P
330. y an accepted value of a natural physical constant or a ratio calibration technique The calibration is in compliance with US MIL STD 45662A This option includes a test data report for the oscilloscope The oscilloscope comes standard with the accessories listed in Table A 2 Table A 2 Standard Accessories Accessory Part Number User Manual 070 8991 xx Programmer Manual 070 8709 xx Reference 070 8999 xx Performance Verification 070 8990 xx TDS 744A Four P6139A 10X 500 MHz Passive probes P 6139A Front Cover 200 3696 00 Accessory Pouch 016 1268 00 U S Power Cord 161 0230 01 TDS 684A TDS 744A amp TDS 784A User Manual A 3 Appendix A Options and Accessories Optional Accessories A 4 Accessory Probes You can also order the optional accessories listed in Table A 3 Table A 3 Optional Accessories Accessory Part Number Service Manual 070 8992 xx Plotter GPIB and Centronics Standard HC 100 Oscilloscope Cart K420 Rack Mount Kit for field conversion 016 1236 00 Soft Sided Carrying Case 016 0909 01 Transit Case 016 1135 00 GPIB Cable 1 meter 012 0991 01 GPIB Cable 2 meter 012 0991 00 Centronics Cable 012 1250 00 The following optional accessory probes are recommended for use with your oscilloscope m P6245 Active high speed digital voltage probe FET DC to 1 GHz 50 Q input m P6101B 1X 15 MHz Passive probe m P6156 10X 3 5 GHz Passive low capacitance low impeda
331. you to alter color settings for various display components such as waveforms and text To find more information on color see Customizing the Display Color on page 3 33 TDS 684A only Press DISPLAY gt Style main gt Vectors Intensified Samples Dots Infinite Persistence or Variable Persistence side See Figure 3 17 TDS 700A models only Press DISPLAY gt Mode main gt Normal pop up gt Style main gt Vectors Intensified Samples Dots Infinite Persistence or Variable Persistence side Vectors style displays vectors lines between the record points Dots style displays waveform record points as dots Intensified Samples style also displays waveform record points as dots However the points actually sampled are displayed in the color labeled Zone in the Display Colors menus In addition to choosing Intensified Samples in the side menu the oscilloscope must be interpolating equivalent time must be off for TDS 700A models or Zoom must be on with its horizontal expansion greater that 1X See Interpola tion on page 3 18 see Zooming on Waveforms on page 3 37 Variable Persistence style accumulates the record points on screen and displays them only for a specific time interval In that mode the display behaves like that of an analog oscilloscope You enter the time for that option with the keypad or the general purpose knob Record points are also displayed with colors that vary depending on the persistence of
332. ypad 2 7 2 22 Knob Glossary 6 General purpose 2 7 2 21 Glossary 4 Horizontal POSITION 2 13 3 14 Horizontal SCALE 2 13 3 14 Trigger MAIN LEVEL 2 14 3 53 Vertical POSITION 2 13 3 10 Vertical SCALE 2 13 3 10 L Labelling menu Enter Char 3 118 3 119 Landscape Hardcopy menu 3 122 Laserjet 3 121 Laserjet Hardcopy menu 3 122 Layout Hardcopy menu 3 122 Level Delayed Trigger menu 3 85 Level Main Trigger menu 3 60 3 74 3 77 Level Trigger 3 53 LF Rej Main Trigger menu 3 58 Lightness Color menu 3 34 Limit Test Condition Met Acquire menu 3 141 Limit Test Setup Acquire menu 3 140 3 141 Limit Test Sources Acquire menu 3 140 Limit Test Acquire menu 3 141 Limit Testing Incompatible with InstaVu 3 45 Limit testing 3 137 3 170 Linear interpolation 3 19 3 31 Glossary 5 Linear interpolation Display menu 3 31 Logic trigger 3 50 3 62 Definitions 3 62 Pattern 3 61 Glossary 6 Readout 3 64 State 3 62 Glossary 6 Logic triggering 3 60 3 86 Logic Main Trigger menu 3 57 Low 3 89 Glossary 6 Low impedance Zo probes E 2 Low Ref Measure menu 3 94 Main menu Glossary 6 Main menu buttons 2 3 Glossary 6 Main Scale Horizontal menu 3 15 Main Trigger Menu Falling edge 3 60 Rising edge 3 60 Index 7 Index Main Trigger menu 3 57 3 58 3 64 3 67 3 68 3 72 3 74 3 77 AC 3 58 Accept Glitch 3 73 AND 3 66 3 68 Auto
333. zone on the main timebase record that shows where the delayed timebase record occurs relative to the main trigger For Delayed Runs After Main mode the start of the intensified zone corresponds to the start of the delayed timebase record The end of the zone corresponds to the end of the delayed record To Trigger After Delay To make sure that the Main Trigger menu settings are compatible with Delayed Triggerable and to select that mode do the following steps 1 Press TRIGGER MENU 2 If Type is set to Logic press Type main to change it to either Edge or Pulse as fits your application Logic type is incompatible with Delayed Triggerable 3 If Source is set to Auxiliary press Source main Select any source other than Auxiliary from the side menu according to your application 4 If Type is set to Pulse press Class main and change it to either Glitch or Width as fits your application Runt and Slew Rate pulse classes are incompatible with Delayed Triggerable 5 Press HORIZONTAL MENU gt Time Base main gt Delayed Only side gt Delayed Triggerable side NOTE The Delayed Triggerable menu item is not selectable unless incompatible Main Trigger menu settings are eliminated See the steps at the beginning of this procedure If such is the case the Delayed Triggerable menu item is dimmer than other items in the menu TDS 684A TDS 744A amp TDS 784A User Manual 3 83 Triggering on Waveforms 3 84 By pr

Tektronix TDS744A Manual

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