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User Manual TDS 694C Digital Real-Time Oscilloscope 071-0473-00

1. MIDICIC IO O O Figure 3 38 Pulse Trigger Readouts Table 3 4 Pulse trigger definitions Name 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 Y widths less than the specified glitch time wrm Glitch either Triggering occurs if the oscilloscope detects positive or negative widths less than the specified glitch time ia Runt positive Triggering occurs if the oscilloscope detects a positive pulse Nee that crosses one threshold going positive but fails to cross a second threshold before recrossing the first going negative tft Runt negative Triggering occurs if the oscilloscope detects a negative N going pulse that crosses one threshold going negative but fails to cross a second threshold before recrossing the first going positive fga Runt either Triggering occurs if the oscilloscope detects a positive or ay negative going pulse that crosses one threshold but fails to cross a second threshold before recrossing the first Width positive 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 T Width negative Triggering occurs if the oscilloscope finds a negative pulse with a width between or optionally outside the user spe
2. Limit Test Condition Met LOlOIDICDIa 2oomv SM 500s Chit 248mv Mode Stop After Limit Test Limit Test create Limit Test Sample A S button Setup sources Template II 101 1 1 Figure 3 12 Acquire Menu Stop After 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 RUN STOP Foot Switch performs the same function as the RUN STOP button only The foot switch is recommended when both hands are needed to probe two test points To toggle the RUN STOP function you can easily step on the foot switch The foot switch connects to the TDS 694C Oscillo scope s RS 232 port located on the rear panel See Appendix A Table A 2 for Standard accessories Set Communications Parameters To set up the communication parameters for a foot switch attached directly to the oscilloscope RS 232 port Press SHIFT gt UTILITY gt System main gt I O pop up gt Config ure main gt Foot Switch RUN STOP side Press Single Acquisition Sequence side That selection lets you run a single sequence of acquisitions by pressing the RUN STOP button In Sample Peak Det
3. TDS 694C User Manual 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 2 Press SETUP gt Recall Factory Setup main gt OK Confirm Factory Init side 3 Press AUTOSET 4 Press MEASURE to display the Measure main menu See Figure 2 14 5 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 displayed at any one time Pressing the button next to the more menu item brings up the other measurement selections 6 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 1 waveform To take
4. gt Start Posttrigger Acquisition From Delay Trig Menu First Trigger After Delay Delayed Triggerable By Events Time Main Trigger P oint k elis Trigger Waveform Record gt Main Trigger Source l Trigger Source ee EUN Waiting for nth Event H Time Delay Start Posttrigger Acquisition Where n 4 From Delay Trig Menu Figure 3 44 How the Delayed Triggers Work TDS 694C User Manual 3 83 Triggering on Waveforms 3 84 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 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 By pressing 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 en
5. Source Waveform To Take Automated Measurements To Take Cursor Measurements 3 174 Tek Run 5 00MS s Sample hatht ch 20 0mva Math 1 i 200kV s Math2 FFECCHK 10 08 Math3 inchi Ref1 M 10 0 chi T Ref2 _ ov Ref3 Math Change Math waveform definition No Extended m Processing Average 2 Ref4 C3 C2 C Figure 3 91 Derivative Math Waveform Oloo o 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 Measure pop up gt Select Measrmnt main 3 Select up to four measurements in the side menu See Figure 3 92 You can also use cursors to measure derivative waveforms Use the same procedure as is found under To Take Cursor Measurements on page 3 179 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 694C Us
6. M 30049 chi T ov Remove Gating Statistics Level Setu Measure Measrmnt Measrmnt Histogram Snapshot Oooo oj lt Measure gt forchi oloo Figure 3 49 Measure Menu Gating 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 gated You must turn gating off in the Gating side menu TDS 694C User Manual 3 93 Measuring Waveforms Define High Low Setup Define Reference Levels 3 94 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 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 Hi Low Setup main gt Histogram or Min Max side If you select Min
7. ccccecsccccccccccscsccsees 3 101 Figure 3 54 Cursor Modes cece ce cc cec cece ecececes 3 102 Figure 3 55 H Bars Cursor Menu and Readouts 3 103 Figure 3 56 Paired Cursor Menu and Readouts 3 104 Figure 3 57 Histogram Menu and Vertical Histogram 3 107 Figure 3 58 Performing a Signal Path Compensation 3 111 Figure 3 59 Probe Cal Menu and Gain Compensation Display 3 113 Figure 3 60 Re use Probe Calibration Data Menu 3 115 Figure 3 61 Save Recall Setup Menu cece eee eeee 3 118 Figure 3 62 Save Waveform Menu ccececcscsccsees 3 121 Figure 3 63 More Menu ccc cee cece e cece eee ee eees 3 123 Figure 3 64 File Utilities 0 cc ccc cece cece eee e eens 3 125 Figure 3 65 File System Labeling Menu 206 3 126 Figure 3 66 Utility Menu System I O cece eee enone 3 131 Figure 3 67 Hardcopy Formats ecccceccccscsceeees 3 132 Figure 3 68 Date and Time Display ceccececceees 3 133 Figure 3 69 Connecting the Oscilloscope Directly to the Hardcopy Device iis 6 is iaie 96150 tos Bisa EEren Ohi woe gle wa ere ear eee 3 134 Figure 3 70 Connecting the Oscilloscope and Hardcopy Device Viaia PC oie dines 25 doers Siti obi E E ble ao ihe Sis 3 137 Figure 3 71 Typical GPIB Network Configuration 3 140 Figure 3 72 Stacking GPIB Connectors
8. gt M 500s Chis 27 2mv more LOIOIDIC O DIGIC GAG SBS e Figure 3 61 Save Recall Setup Menu 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 TDS 694C User Manual 3 116 Saving Waveforms and Setups NOTE Upon power on the oscilloscope creates the wild card file marked in the on the left of this page 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 From Selected File side to complete the operation 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 c
9. 0 0 eee eee eee eee 3 122 Printing a Hardcopy s pecetea epa cee a a eee 3 127 Communicating with Remote Instruments 00 000005 3 137 Determining Status and Displaying Status 0 cnc errur arrn ences 3 141 Accessing Help Displaying the Banner 0 2 00 0 e cee cece ce cece ceeeeeceueeees 3 143 Displaying Help sic hes kes be a pa esha be SA awe See eA es 3 143 Using Features for Limit Testing 00 0 e ene e ne enes 3 145 Advanced Applications Waveform Math 000000 cece cece renren errereen rren 3 150 Fast Fourier Transforms 0 0 0 e eee eee eens 3 153 Waveform Differentiation 0 eee eee eee 3 172 Waveform Integration 2 eects 3 177 TDS 694C User Manual 3 2 E ee Acquiring and Displaying Waveforms To use the TDS 694C Oscilloscopes 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 displa
10. Measure Inca es a 4 a Soois chi 7 gm HO ahi Counting OIIO Measure Histogram MICOIC OC IOC Measrmnt Measrmnt Figure 3 57 Histogram Menu and Vertical Histogram Start Histogram Counting To start histogram counting press MEASURE gt Histogram pop up gt Histogram Options main gt Histogram Mode side gt Off Vertical or Horizontal side Off turns off histogram counting and display m Vertical displays a vertical histogram that shows how your vertical units vary in the histogram box A vertical histogram is displayed starting at the left edge of the graticule The size of the max bin is controlled by the Histogram Size side menu m Horizontal displays a horizontal histogram that shows how time varies in the histogram box A horizontal histogram is displayed at the top of the graticule The size of the max bin is controlled by the Histogram Size side menu Reset Histogram Counting To reset the count in all histogram bins to zero press MEASURE gt Histogram pop up gt Histogram Options main gt Reset Histogram Counting side TDS 694C User Manual 3 105 Measuring Waveforms Display a Histogram Setting Histogram Box Size To Move the Histogram 3 106 Box To display a histogram press MEASURE gt Histogram pop up gt Histo gram Options main gt Histogram Display side gt Off Log or Linear s
11. Figure 3 10 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 In Envelope mode the oscilloscope acquires and displays a waveform record that shows the extremes in variation over several acquisitions you specify the number of acquisitions 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 acquires data after each trigger event using Sample mode It then averages the record point from the current acquisition with those sto
12. LOlOID IOle 11010901 1 1c Figure 3 60 Re use Probe Calibration Data Menu 3 113 Measuring Waveforms Table 3 7 shows the action the oscilloscope takes based on the probe connected and user operation performed Table 3 7 Probe cal status Type probe connected TEKPROBE interface No Doesn t Matter Initialized Initialized Power off Initialized Initialized probe data is retained probe data is retained Probe Cald User action Simple interface Yes Poweron Can not 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 If no probe is connected the probe status in the vertical main menu is always initialized 3 Aprobe with a simple interface is a probe that can convey very limited information to the oscilloscope Most passive probes such as the P6158 have simple interfaces 4 Aprobe with a TEKPROBE interface is a probe that can convey additional information For i
13. Table A 1 Options Option Label Description Al Universal European 220 V 50 Hz power cord power cord A2 UK power cord 240 V 50 Hz power cord A3 Australian power cord 240 V 50 Hz power cord A5 Switzerland powercord 220 V 50 Hz power cord 1K Scope cart K420 scope cart This cart can help transport the oscilloscope around many lab environ ments 1M 120 000 samples record Extend record length from 30 000 samples standard length 1R Rackmount Oscilloscope comes configured for installation in a 19 inch wide instrument rack For later field conversions order kit 016 1236 00 31 Buffered passive probe Add a 500 MHz P6339A 10x buffered passive probe 33 Low capacitance probe Add a3 GHz probe only P6158 20x 1 KQ low capacitance probe 37 Active probe Add a 1 5 GHz probe only P6245 high speed digital voltage probe 38 Active probe Add a 4 GHz probe only P6249 5X small geometry active probe 39 Differential probe Add a 1 5 GHz probe only P6248 small geometry active differential probe C3 Three years calibration Provides three years of calibration C5 Five years calibration Provides five years of calibration D1 Calibration data report Oscilloscope comes with a calibration data report D3 Calibration data for C3 Provides calibration data for option C3 D5 Calibration data for C5 Provides calibration data for option C5 TDS 694C User Manual Appendix A Options and Accessories Table A 1 Options cont Option Label Descrip
14. cece cece ewes 3 26 Figure 3 15 Trigger Point and Level Indicators 3 27 Figure 3 16 Display Menu Setting cece eee eee 3 30 Figure 3 17 Display Menu Palette Colors 66 3 32 Figure 3 18 Display Menu Map Reference Colors 3 33 Figure 3 19 Display Menu Restore Colors 206 3 34 Figure 3 20 Zoom Mode with Horizontal Lock Set to None 3 37 Figure 3 21 Dual Window Preview Mode eseeee8 3 38 Figure 3 22 Dual Zoom Shown Dual Window Preview Mode ccccccc cece cc cccccecccccesececes 3 40 Figure 3 23 Triggered Versus Untriggered Displays 3 42 Figure 3 24 Trigger Holdoff Time Ensures Valid Triggering 3 44 Figure 3 25 Slope and Level Controls Help Define the Trigger 3 45 Figure 3 26 TRIGGER Controls and Status Lights 3 46 Figure 3 27 Example Trigger Readouts Edge Trigger Selected issse co cine baie oo has eee n eE S 3 48 Figure 3 28 Record View Trigger Position and Trigger Level Bar READ OUWUS corie ine tn e Eo ae EEA ae EEEE EORR ie Ses 3 49 Figure 3 29 Edge Trigger Readouts ce cece eee eees 3 50 Figure 3 30 Main Trigger Menu Edge Type 3 50 Figure 3 31 Violation Zones for Setup Hold Triggering 3 56 Figure 3 32 Logic Trigger Readouts State Class Selected 3 57 Figure 3 33 Logic Trigger Menu ccccec
15. m 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 m Use High Low Setup page 3 94 Reference Levels page 3 94 and Gated Measurements page 3 92 with Snapshot exactly as you would when you display individual measurements from the Select Measrmnt menu To perform a tutorial that shows you how to take automatic measurements see Example 3 Taking Automated Measurements on page 2 20 To learn how the oscilloscope calculates each automatic measurement see Appendix B Algorithms on page B 1 Taking Cursor Measurements 3 98 The TDS 694C Oscilloscopes 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 TDS 694C User Manual Measuring Waveforms Cursor Types There are three cursor types horizontal bar vertical bar and paired see Figure 3 53 YV x Horizontal Bar Cursors Ver
16. EndCycle Waveform t dt tartCycle CycleRMS EndCycle StartCycle x SampleInterval For details of the integration algorithm see page B 15 Appendix B Algorithms Delay Extinction Ratio Extinction Extinction dB Fall Time as Timing measurement The amount of time between the MidRef and 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 Optical measurement between 1 and 100 In real circuits the extinction ratio is typically 8 to 30 Values 1 or 100 generate errors An Extinction Ratio of 1 or 100 means a problem exists The optical probe and the oscilloscope must be calibrated All inputs are micro watts and are not negative Extinction ratio is dimensionless Extinction Ratio High Low Low 2 1 uW Optical measurement Extinction 100 0 Extinction Ratio Optical measurement Extinction dB is typically 8 to 12 db To exceed this range the input may be from nonoptical probes or noncommunication lasers Extinction dB 10 0 logj9 Extinction Ratio Timing measurement The time
17. Masks lofts Histogram Remove Gating Statistics Level Setu Measure EEG ia j Snapshot lt Measure gt may Measrmnt OFF Histogram ICCC OIC OIOI JO Figure 3 48 Measure Menu m Becareful when taking automatic measurements using Extended Acquisition mode and high levels of waveform compression The compression may remove signal attributes required by some 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 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 TDS 694C User Manual Measuring Waveforms 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 49 Tek Run 100kKS 5 Sample ow
18. 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 Ch1 Ch2 Ch3 or Ch4 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 Logic pop up gt Class main 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 Logic pop up gt Class main State pop up gt Trigger When main Goes TRUE or Goes FALSE side TDS 694C User Manual 3 59 Triggering on Waveforms 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 49 To learn more about trigger mode and holdoff see the descriptions Trigger Modes and Trigger Holdoff on page 3 41 To Trigger on Setup When you select the logic class Setup Hold the oscilloscope uses one channel as Hold Time Violations a data channel the factory default setting is Ch1 another channel as a clock channel default is Ch2 and triggers if the data transitions within the setup
19. Stop shows the number of acquisitions acquired since the last stop or major change Run Tookes Sample Acquisition Mode Sample Peak Detect gilt Envelope 18 200mv LOM 500us Chi 248mVv g H i Average i 16 Mode Stop After Limit e Limit Test create Limit Test Sample R S button Setup Sources Template MIP Figure 3 11 Acquisition Menu and Readout The oscilloscope provides several modes see The Acquisition Modes on page 3 17 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 11 2 Press Sample Envelope Average or Peak Detect side or 3 Ifyou selected Envelope or Average enter the number of waveform records to be enveloped or averaged using the keypad or the general purpose knob To choose the event that stops the 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 12 TDS 694C User Manual Acquiring and Displaying Waveforms TDS 694C User Manual Tek Run 100349 Sample stop After RUNZSTOP button only Single Acquisition Sequence
20. 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 TDS 694C User Manual 3 57 Triggering on Waveforms Note the position of the trigger indicator in Figure 3 34 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 m It compares the times and if the time TRUE is longer for TRUE for more than or shorter for TRUE for 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 34 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 Tek Stopped 4671 Acquisitions True gt 150 0000us r n AE d A 216 Logic Pattern Time Lo
21. 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 FFT length j is 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 82 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 694C User Manual 3 154 Using Features for Advanced Applications Tek Stopped 820 Acquisitions i i s Mdth3 Zoom 0 5X vent 2 0x Horz Normal Waveform of an Impulse Response FFT Waveform of the t ee a ioi Magnitude Response FFT Waveform of the gt 1
22. 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 ast 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 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 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 3 133 Saving Waveforms and Setups To Save to a Disk 3 134 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 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 3 128 2 If saving to a floppy disk 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 ot
23. cece cee eee nee eee 3 90 Taking Cursor Measurements 0 0 c eee eee cece n eens 3 100 TDS 694C User Manual Table of Contents Appendices Glossary Index Taking Graticule Measurements 0 0 0 cece eee eee eee Displaying Histograms 0 cece eee e eee Optimizing Measurement Accuracy SPC and Probe Cal Saving Waveforms and Setups cccccccceccccsscscees Saving and Recalling Setups 0 0 0 cee ee eee Saving and Recalling Waveforms and Acquisitions 0 Managing the File System 0 0 0 eee Printing a Hardcopy np he coe ee ee eG A Oe See ROSES Communicating with Remote Instruments 00 0200005 Determining Status and Accessing Help cceceeeeees Displaying Status srete coding be See ek Se bee eRe Sains Rise EERS E Displaying the Banner 20 eee eee eee nee Displaying Help cristeri repesne tte ge Sle ew be ple be ENE Using Features for Advanced Applications 0 eee08 Limit Testin 2 5 nis die ning beanie edie eee eR eed Waveform Math g 5 ses ee eek ees Se ee ee Fast Fourier Transforms 0 0 000 n eens Waveform Differentiation 0 0 eee eens Waveform Integration 0 cece eee eee nent n eens Appendix A Options and Accessories ce cece cece eee Appendix B Algorithms 0 cece cece cece cere eee eeee Appendix C Packaging for
24. istogram mean he percentage of points in the histogram which are within 3 standard deviations of the istogram mean 7 h The percentage of points in the histogram which are within 2 standard deviations of the h 7 h Histogram measurements are displayed in the same location as other measure ments See Figure 3 47 on page 3 91 To display histogram measurements you first need to obtain a stable display of your waveform Pressing AUTOSET may help Once you have a stable display press MEASURE to bring up the Measure menu See Figure 3 48 1 Turn on histogram counting by pressing MEASURE gt Histogram pop up gt Histogram Options main gt Histogram Mode side gt Vertical or Horizontal side 2 Press MEASURE gt Histogram pop up gt Histogram Measrmnt main 3 Select a measurement from the side menu see Table 3 6 on page 3 107 3 107 Measuring Waveforms Remove Measurements The Remove Measrmnt selection provides the same functions as in the Measure menu See Remove Measurements on page 3 92 Optimizing Measurement Accuracy SPC and Probe Cal 3 108 Signal Path Compensation The TDS 694C Oscilloscopes provides three features that optimize measurement accuracy Signal Path Compensation SPC lets you compensate the internal signal path used to acquire the waveforms and measure based on the ambient temperature Channel Probe Deskew lets you compensate for the fact that signals
25. 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 m For records with a 100 K length 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 length nor if your oscilloscope model is so equipped and of the record lengths 30 K 75 K or 130 K to impulse test using 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
26. n y n scale gt ME 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 3 177 Using Features for Advanced Applications To Create a Integral Math 3 178 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 gt 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 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 93 Use the Vertical SCALE and POSITION knobs to size and position your waveform as you require TDS 694C User Manual Using Features for Ad
27. Figure 3 36 TLA 714 to TDS 694C oH LA 720 Logic Analyzer i TDS 694C Oscilloscope Aux Trigger Input x with a 50Q terminator Coaxial cable P6041 Figure 3 37 TLA 720 to TDS 694C TDS 694C User Manual Triggering on Waveforms TDS 694C User Manual Time Delay Characterization After the connections have been made between the TLA Logic Analyzer and the TDS 694C a trigger delay characterization should be performed 1 Install a deskew fixture see page 2 10 onto the TDS 694C probe compensa tion pins 2 Connect a P6249 probe to channel 1 3 Attach the P6249 probe to one set of square pins on the deskew fixture 4 Attach one data channel from a TLA Logic Analyzer to another set of pins on the deskew fixture NOTE For ground and signal pin locations on the deskew fixture see Figure 2 1 page 2 9 NOTE If the TLA Logic Analyzer probing prevents connection to the TDS 694C oscilloscope s probe compensation signal then the user will have to attach the TDS 694C probe to a signal on their prototype that is also probed by the TLA Logic Analyzer The signal used should have an event that is uniquely recogniz able within a 1 us interval The TDS 694C vertical setting will have to match the signal TLA Logic Analyzer setup 1 Set the TLA Logic Analyzer trigger threshold to 0 25 V 2 Set the TLA Logic Analyzer to trigger on the rising edge of the at
28. Main Trigger Main Time Base Time Di ain Time Base Time Div Source Ch 1 Main Trigger Main Time Base Level fam 200mv CF M 500us Chif Ea i 11101 1 1 TYPE Source lt Edge gt Chi Coupling BC Figure 3 29 Edge Trigger Readouts 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 Edge pop up See Figure 3 30 Z Tek Run 100kS s Sample Edge Source ch2 Logic k Pulse jomy M 500s Chif 248mV more 1of2 See coupling Slope Level ode Type l amp ep apes cal BC f 24asmv kor ea ee es e Oooo JO Figure 3 30 Main Trigger Menu Edge Type TDS 694C User Manual Triggering on Waveforms To Select a Source To Specify Coupling DC Mg To Set Mode amp Holdoff TDS 694C User Manual To select which source you want for the trigger Press TRIGGER MENU gt Type main Edge pop up gt Source main Ch1 Ch2 Ch3 Ch4 AC Line DC Aux or TLA Cross Trigger DC Aux Rear Panel side To select the coupling you want press TRIGGER MENU gt Type main Edge pop up gt Coup
29. Min Max Measure menu 3 96 Minimum 3 91 Glossary 7 Mode amp Holdoff Main Trigger menu 3 51 Model number location 2 3 Models key features and differences 1 3 Monochrome Color menu 3 31 MORE button 3 9 3 123 3 150 3 153 More menu 3 123 3 153 3 175 Average 3 155 Blackman Harris 3 159 Change Math waveform definition 3 157 3 175 3 180 dBV RMS 3 158 diff 3 175 Dual Wfm Math 3 154 FFT 3 157 Hamming 3 159 Hanning 3 159 intg 3 180 Linear RMS 3 158 Math1 Math2 Math3 3 157 3 175 3 180 Math1 2 3 3 155 No Process 3 155 OK Create Math Waveform 3 153 3 180 Phase deg 3 158 Phase rad 3 158 Rectangular 3 159 Reference waveform status 3 123 Set 1st Source to 3 154 Set 2nd Source to 3 154 Set FFT Source to 3 157 Set FFT Vert Scale to 3 158 Set FFT Window to 3 159 Set Function to 3 153 Set Function to 3 175 3 180 Set operator to 3 154 Set Single Source to 3 153 3 154 Set Single Source to 3 175 3 180 Single Wfm Math 3 153 3 175 3 180 N NAND Glossary 7 NAND Main Trigger menu 3 59 3 61 Negative duty cycle 3 91 Negative overshoot 3 91 Negative width 3 91 Negative Main Trigger menu 3 72 3 74 3 77 No Process More menu 3 155 Noise reducing in FFTs 3 166 Index 9 Index reducing in phase FFTs 3 159 3 169 Noise Rej Main Trigger menu 3 51 NOR Glossary 7 NOR Main Trigger menu
30. Pattern pop up gt Define Logic main 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 Logic pop up gt Class main Pattern pop up gt Trigger When main 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 49 To learn more about trigger mode and holdoff see the descriptions Trigger Modes and Trigger Holdoff on page 3 41 To Define a Time Qualified You can also time qualify a pattern logic trigger That is you specify a time that Pattern Trigger 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 Pattern pop up gt Trigger When main TRUE for less than or TRUE for more than side 2 Use the knob and keypad to set the time in the side menu
31. Phase Response sleleel i M s00ps Chis 2 52 V tha 250m DEUE 90 07 2 50kHz Oooo Figure 3 82 System Response to an Impulse To Create an FFT To obtain an FFT of your waveform do the following steps 1 2 TDS 694C User Manual 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 3 163 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 83 Press Set FFT Source to side repeatedly until the channel source selected in step 1 appears in the menu label 3 155 Using Features for Advanced Applications Tek Run 50 0MS s 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 ear When you are satisfied with the selections press amplitudes lt Create Math wfm 3dB Press CLEAR MENY to return to
32. See Figure 3 71 Do not create loop configurations GPIB Device GPIB Device GPIB Device Figure 3 71 Typical GPIB Network Configuration GPIB Device GPIB Device GPIB Device GPIB Device 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 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 72 Figure 3 72 Stacking GPIB Connectors TDS 694C User Manual 3 138 Saving Waveforms and Setups To Set Up for Remote Operation TDS 694C User Manual 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 73 Controller Oscilloscope Rear Panel GPIB Connector Figure 3 73 Connecting
33. 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 49 To learn more about trigger mode and holdoff see the descriptions Trigger Modes and Trigger Holdoff on page 3 41 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 Pulse pop up gt Class main Runt pop up See Figure 3 40 3 71 Triggering on Waveforms 3 72 Select the Source To specify which channel becomes the pulse trigger source Press TRIGGER MENU gt Type main Pulse pop up gt Source main 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 Pulse pop up gt Class main Runt pop up gt Polarity main Positive Negative or Either side Positive looks for positive going runt pulses 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
34. Zone T IH s nee at Clock Level Clock Signal Positive Tc Negative T4 Negative Ts Positive Ty t amp gt Figure 3 31 Violation Zones for Setup Hold Triggering TDS 694C User Manual 3 54 Triggering on Waveforms Ch 1 2 3 Inputs High Don t Care Don t Care Ch 4 Input Rising Edge Trigger Class State Logic OR Pulse om T af T on S00us 2 state Hixxy z Define Inputs ode amp Holdoff Trigger Class when lt State gt Goes TRUE Type lt Lagic gt Figure 3 32 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 set the selected level while the Main Trigger menu is set to Logic To Trigger ona Pattern When you select the logic class Pattern the oscilloscope will trigger on a specified logic combination of the four input channels Pages 3 51 through 3 52 describe how pattern triggers work To use pattern triggering do the procedures that follow Select Pattern Triggering Press TRIGGER MENU gt Type main Logic pop up gt Class main Pattern pop up TDS 694C User
35. gt Full Grid Cross Hair Frame NTSC or PAL side Full provides a grid cross hairs and a frame Grid displays a 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 TDS 694C User Manual Acquiring and Displaying Waveforms Select the Format bri IO TDS 694C User Manual The oscilloscope displays waveforms in either of two formats YT and XY To set the display axis format Press DISPLAY gt Settings main gt Display pop up gt Format main gt XY or YT side YT is the conventional oscilloscope display format It shows a signal voltage the vertical axis as it varies over time the horizontal axis 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 relat
36. ye Tek Run TOOKS S Sample pees Version F 3 8e Horiz Sca Tre Pos Status Snapshot Main SCOS Main 50 500 10 divs 50 0 Dlyd 5S0us Runs After t6ns OFF 250 2 zoom Status Vert Horiz lock Dual Zoom DZ Offset OFF 2 8 20 All OFF S 00ms Acquire Mode Repet Stop Sampie On R S button 500 imit Test St Rell OFF OFF OFF Limit Source Chi Ch2 Ch3 Ch4 Mathi Math Math3 System Display Trigger Refi Aone None None None None Wore Measure Gate Hi Low OFF Histogram 90 50 10 50 Format layout Port Palette interieaf Portrait File Hardcopy Status Banner Waveforms more 1of2 OOOO Doala aolo Figure 3 75 Status Menu System TDS 694C User Manual Determining Status and Accessing Help Displaying the Banner To display the banner lists firmware version options copyright and patents Press SHIFT STATUS gt Banner main See Figure 3 76 ir A Tek Run 100kKS 5 Sample InstaVu Brightness 50 Tektronix 7 TDS 694C Digitizing Oscilloscope F o8jang8 1e Options HD 1M c Copyright Tektronix Inc 1991 1999 All rights reserved Oloo ooo Figure 3 76 Banner Display Displaying Help To use the on line help system Press HELP to provide on sc
37. 3 118 Fall time 3 91 Glossary 4 Falling edge Delayed Trigger menu 3 87 Falling edge Main Trigger menu 3 52 3 61 3 62 Fast Fourier Transforms description 3 155 Fast Fourier Transforms FFTs applications 3 155 FFT frequency domain record 3 162 defined 3 163 length of 3 164 FFT math waveform 3 156 acquisition mode 3 166 aliasing 3 167 automated measurements of 3 162 DC correction 3 165 derivation of 3 156 displaying phase 3 158 frequency range 3 164 frequency resolution 3 164 interpolation mode 3 166 3 167 magnifying 3 166 phase display setup considerations 3 168 phase suppression 3 159 3 169 procedure for displaying 3 157 procedure for measuring 3 160 record length 3 164 reducing noise 3 166 undersampling 3 167 zero phase reference 3 168 FFT time domain record defined 3 163 File System 3 124 File Utilities menu 3 125 Confirm Delete 3 127 Copy 3 127 Create Directory 3 127 Delete 3 126 Drives 3 128 File Utilities 3 125 Format 3 128 Icons 3 119 3 122 3 126 3 128 Overwrite Lock 3 128 Print 3 127 Rename 3 126 TDS 694C User Manual File Utilities File Utilities menu 3 125 File Utilities Save Recall Setup menu 3 120 File Utilities Save Recall Waveform menu 3 124 Filter Display menu 3 28 Fine Scale Vertical menu 3 13 Firmware version 3 143 Fit to screen Horizontal menu 3 16 Fixtured active probes D 4 Foot Switch RUN STOP Utilit
38. 81 3 82 TLA Cross Trigger 3 64 TLA Cross Trigger Main Trigger menu 3 51 TDS 694C User Manual Tracking Cursor menu 3 104 Trigger 3 41 3 88 Glossary 11 AC Line Voltage 3 42 Auxiliary 3 42 Coupling 3 44 Delay 3 45 Delayed 3 82 3 88 Edge 3 43 3 49 Glossary 4 Glitch 3 69 3 70 Glossary 5 Holdoff 3 44 Level 3 45 Glossary 11 Logic 3 43 3 53 3 54 Mode 3 43 Pattern 3 53 3 57 Position 3 16 3 45 Pulse 3 43 3 69 Readout 3 48 Runt 3 69 3 70 Glossary 10 Setup Hold 3 53 3 54 3 62 3 88 Slew Rate 3 71 Glossary 10 Glossary 11 Slew rate 3 69 Slope 3 45 Source 3 42 State 3 53 3 61 3 88 Status Lights 3 47 Timeout 3 69 3 71 3 81 Glossary 11 TLA Cross Trigger 3 64 Types 3 49 3 88 Width 3 69 3 76 Trigger Bar 2 6 Trigger Bar Style Display menu 3 27 Trigger if Faster Than Main Trigger menu 3 79 Trigger if Slower Than Main Trigger menu 3 79 Trigger Level Bar Readout 3 26 Trigger MAIN LEVEL knob 2 15 3 45 3 46 TRIGGER MENU button 3 49 3 50 3 57 3 61 3 62 3 71 3 73 3 77 Trigger Point Readout 3 26 Trigger Position Horizontal menu 3 16 Trigger Status Lights 3 47 Trigger When Main Trigger menu 3 59 3 61 3 78 Trigger delayed How to set up 3 84 Trigger edge How to set up 3 50 Trigger glitch How to set up 3 71 Trigger runt How to set up 3 73 3 88 Trigger slew ra
39. H Bars Cursor Function Non selected Cursor Dashed Line Selected Cursor Solid Line Select the Cursor Function TDS 694C User Manual 20 0mVv M 300s chi 7 25 6mv a rine Tanpi ESEA Dead runetion Mone Units Units seconds Base OIOI o Co C EEE Figure 3 55 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 This procedure and those that follow detail the process for taking a cursor measurement To select the type of cursors you want do the following steps 1 To display the cursor menu press CURSOR See Figure 3 55 2 Press Function main gt H Bars V Bars Paired or Off side 3 101 Measuring Waveforms Cursor Readout Paired Non selected Cursor Dashed Vertical Bar Selected Cursor Solid Vertical Bar Set Mode and Adjust the Cursors 3 102 Position of Vertical Bar Cursors Useful for Locating Cursors Outside the Display Cursor Function i l 3 10 0m o M 200ps Chi y 25 6mV p Function ime mpTitude Paired Units seconds OIOI o Figure 3 56 Paired Cursor Menu and Reado
40. 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 Timeout trigger A trigger mode in which triggering occurs if the oscilloscope does NOT find a pulse of the specified polarity and level within the specified time period 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 Glossary 11 Glossary Vertical 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 Waveform interval The time interval between record points as displayed aes XY format A display format that compares the voltage level of two waveform records point by point It is useful for studying phase rela
41. Zp Low impedance probes measure frequency more accurately than general purpose Probes 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 Zp probes ideal for timing and phase measurements when amplitude accuracy is not a major concern Zo probes are useful for measurements up to 40 V High Voltage Probes 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 TDS 694C User Manual D 2 Appendix D Probe Selection Active Voltage Probes TDS 694C User Manual Figure D 1 Typical High 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
42. el 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 TDS 694C User Manual Triggering on Waveforms Triggering Based on Logic S S TDS 694C User Manual S 5 The TDS 694C Oscilloscopes 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 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 preconditi
43. gt Delete Refs main gt Delete Ref1 Delete Ref2 Delete Ref3 Delete Ref4 or Delete All Refs side TDS 694C User Manual 3 120 Saving Waveforms and Setups 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 3 117 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 63 Note that in Figure 3 63 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 He Tek Run 100kKS 5 Sample Math Change Math waveform definition No Extended mee Processsing Average 2 300m Oooo o Math2 Math3 Chit he Chi Che inv chi G Figure 3 63 More Menu To Recall a Waveform To recall a waveform from disk to an internal reference memory From Disk Press SAVE RECALL WAVEFORM gt Recall Wfm To Ref main gt Recall From File side TDS 694C User Manual 3 121 Saving Waveforms and Setups To Enable Autosave To Run the File Utilities 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 Ref
44. length and so on This section 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 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 TDS 694C User Manual Acquiring and Displaying Waveforms Interpolation and Zoom Checking the Zoom Factor Zoom a Waveform TDS 694C User Manual 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 When zooming horizontally or vertically Zoom expands or contracts the waveform by the zoom factor To help 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
45. oe e aoao Figure 3 40 Main Trigger Menu Runt Class Note the position of the trigger indicator in Figure 3 40 Triggering 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 TDS 694C User Manual 3 73 Triggering on Waveforms Trigger Based on Pulse Width 3 74 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 49 To learn more about trigger mode and holdoff see Trigger Modes and Trigger Holdoff on page 3 41 When you select the pulse class Width the oscilloscope
46. sca Set to ECL Set to 50 SINGLE TRIG FORCE TRIG 200mva C Midons Chie aimv Source Coupling slope EE Mode lt Edge gt Loc Too tit Holdoff Ccaceesese C ND E ust PROBE ATIS 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 694C User Manual Operating Interface Maps To Operate a Pop Up Menu Tektronix TDS 694C stiri ren Twe 0scioscore 0686 Tek Run 100kKS s Sample E Edge Source M 500s Chis 280m TIP Coupling k Cha RG Holdoff J Press to display pop up menus Press here to remove menus from Press it again screen 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 694C User Manual 2 8 E A Tutorial This section quickly makes you acquainted with some of the fundamental operations required to use the TDS 694C Oscilloscopes to
47. the Horizontal menu what percentage of the waveform record will contain pretrigger information 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 The slope control determines whether the oscilloscope finds the trigger point on the rising or the falling edge of a signal See Figure 3 25 You set trigger slope by first selecting Slope in the Main Trigger menu and then selecting between the rising or falling slope icons in the side menu that appears The level control determines where on that edge the trigger point occurs See Figure 3 25 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 iN J Yo Trigger slope can be positive or negative Figure 3 25 Slope and Level Controls Help Define the Trigger 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
48. 03 NOTE Attempting to measure more than 40 amperes of total in phase current DC peak AC using three or more TCP202 current probes installed on the input channels can result in measurement or display errors 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 SONET and Fiber Channel standards optical disk devices digital video and high speed fiber optic communications systems D 5 Appendix D Probe Selection TDS 694C User Manual D 6 Sa Appendix E Inspection and Cleaning General Care Inspection and Cleaning Procedures A TDS 694C User Manual Inspect for dirt and damage on and clean the exterior of the TDS 694C Oscillo scopes When done regularly this preventive maintenance may prevent oscilloscope malfunction and enhance its reliability How often to do this preventive maintenance depends on the severity of the environment in which the oscilloscope is used A proper time to perform preventive maintena
49. 1 MATH1 2 CH2 2 MATH2 3 CH3 3 MATH3 4 CH4 4 REF1 5 REF2 6 REF3 7 REF4 Figure 3 2 Waveform Selection Priority Note Figure 3 2 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 Acquiring and Displaying Waveforms To Find More Information To read about selecting reference waveforms see Saving and Recalling Waveforms on page 3 118 To read about selecting and creating math waveforms see Waveform Math on page 3 150 Scaling and Positioning Waveforms 3 8 To Check Position To Check the Vertical Scale The TDS 694C Oscilloscopes 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 3 shows the results of both vertical and horizontal scaling and positioning This section 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
50. 15 A DC 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 A6312 and P6021 Peak pulse 20 kA 0 5 Hz to 20 MHz with AM 503S A6302 m CT 6 AC Current probe 250 kHz to 2 GHz 50 Q input m P6701B Optical to Electrical Analog Converter 500 to 950 nm DC to 1 GHz 1 V mW m P6703B Optical to Electrical Analog Converter 1100 to 1700 nm DC to 1 2 GHz 1 V mW m P6723 Optical Logic Probe 1310 to 1550 nm 20 to 650 Mb s 8 to 28 dBm m AFTDS Differential Signal Adapter m AMT75 75 Q to 50 Q Adapter TDS 694C User Manual Appendix A Options and Accessories Accessory Software The optional accessories listed in Table A 5 are Tektronix software products recommended for use with your oscilloscope Table A 5 Accessory software Software Part number Wavewriter AWG and waveform creation S3FT400 WaveS tar Waveform capture and documentation WSTR31 WaveS tar Waveform capture and documentation WSTRO Windows 95 NT version 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 TDS 694C User Manual A 5 Appendix A Options and Accessories TDS 694C
51. 155 Math Color menu 3 32 Math1 2 3 More menu 3 155 Maximum 3 91 Glossary 7 Mean 3 91 3 109 Glossary 7 Mean 1 StdDev 3 109 Mean 2 StdDev 3 109 Mean 3 StdDev 3 109 Mean dBm 3 92 B 10 MEASURE button 3 93 3 109 Measure Delay menu Index 8 Create Measrmnt 3 98 Delay To 3 97 Edges 3 98 Measure Delay To 3 97 OK Create Measurement 3 98 Measure Delay To Measure Delay menu 3 97 Measure menu 3 93 3 99 Gating 3 95 High Ref 3 97 High Low Setup 3 96 Histogram 3 96 Low Ref 3 97 Mid Ref 3 97 Mid2 Ref 3 97 Min Max 3 96 Reference Levels 3 96 Remove Measrmnt 3 94 3 99 Select Measrmnt 3 93 3 97 3 109 Set Levels in units 3 96 Snapshot 3 99 Measurement Amplitude 3 90 Glossary 1 Area 3 90 Glossary 2 Burst width 3 90 Glossary 2 Cycle area 3 90 Glossary 3 Cycle mean 3 90 Glossary 3 Cycle RMS 3 91 Glossary 3 Delay 3 97 Glossary 3 Duty cycle 2 22 Glossary 7 Glossary 8 Extinction 3 92 Extinction dB 3 92 Extinction Ratio 3 92 Fall time 3 91 Frequency 2 21 3 91 Glossary 5 Gated Glossary 5 High 3 91 Glossary 5 Histogram 3 109 Histogram counting 3 107 Hits in Box 3 109 Low 3 91 Glossary 6 Maximum 3 91 Glossary 7 Mean 3 91 3 109 Glossary 7 Mean 1 StdDev 3 109 Mean 2 StdDev 3 109 Mean 3 StdDev 3 109 Mean dBm 3 92 Median
52. 26 PAL 3 28 Readout 3 27 3 29 Settings 3 25 3 30 Sin x x interpolation 3 28 Style 3 25 Text Grat 3 26 Trigger Bar 3 27 Variable Persistence 3 26 Vectors 3 25 Waveform 3 26 XY 3 29 YT 3 29 Display Display menu 3 25 Display Status menu 3 143 Dots 3 25 Dots style Display menu 3 150 Dots Display menu 3 25 DPO Glossary 4 DPU411 II Hardcopy menu 3 131 DPU412 Hardcopy menu 3 131 Drives File Utilities menu 3 128 Dual Wfm Math More menu 3 154 Dual Window Zoom 3 37 Dual Zoom Zoom menu 3 38 Dual Zoom Offset Zoom menu 3 39 Duty cycle 2 22 Glossary 7 Glossary 8 E Edge trigger 3 43 3 49 Glossary 4 How to set up 3 50 Readout 3 49 Edge Main Trigger menu 3 49 3 50 Edges Measure Delay menu 3 98 Either Main Trigger menu 3 72 3 74 3 77 empty Saved waveform status 3 121 Encapsulated Postscript 3 129 Enter Char Labelling menu 3 126 3 127 Envelope acquisition mode 3 20 Glossary 4 Envelope Acquire menu 3 22 EPS Color Img Hardcopy menu 3 131 EPS Color Plt Hardcopy menu 3 131 EPS Mono Img Hardcopy menu 3 131 EPS Mono Pit Hardcopy menu 3 131 Epson 3 129 TDS 694C User Manual Index Epson Hardcopy menu 3 131 External Attenuation Vertical menu 3 13 Extinction 3 92 Extinction dB 3 92 Extinction Ratio 3 92 B 8 Extinction ratio Glossary 4 F Factory Setup How to execute 3 8 factory Saved setup status
53. 3 99 Snapshot Measure menu 3 99 Software version 3 143 Source Delayed Trigger menu 3 87 TDS 694C User Manual Index Source Main Trigger menu 3 51 3 72 3 74 3 76 3 77 3 81 Specifications 1 4 Spectral Color menu 3 31 Spooler Hardcopy 3 135 Start up 1 5 State trigger 3 53 3 61 3 88 How to set up 3 61 3 88 State Main Trigger menu 3 61 3 62 Status Determining setup 3 143 STATUS button 3 143 Status menu 3 143 Display 3 143 Firmware version 3 143 Histo Masks 3 143 TO 3 143 System 3 143 Trigger 3 143 Waveforms 3 143 StdDev 3 109 Stop After Limit Test Condition Met Acquire menu 3 151 Stop After Acquire menu 3 22 3 151 Style Display menu 3 25 Switch principal power 1 7 2 5 System Status menu 3 143 System Utility menu 3 23 3 130 T Talk Listen Address Utility menu 3 141 Tek Secure 3 119 Glossary 11 Tek Secure Erase Memory Utility menu 3 119 Temperature compensation 3 110 Temperature Color menu 3 31 Template Source Acquire menu 3 148 Text Grat Display menu 3 26 Thinkjet 3 129 Thinkjet Hardcopy menu 3 131 Thresholds Main Trigger menu 3 74 3 78 TIFF 3 129 TIFF Hardcopy menu 3 131 Time base Glossary 11 Time Base Horizontal menu 3 84 Time Units Cursor menu 3 105 Time Main Trigger menu 3 82 Timeout Trigger 3 71 Timeout trigger 3 69 3 81 Glossary 11 How to set up 3 8 1 3 88 Timeout Main Trigger menu 3
54. Envelope Add Distortion Peak Detect 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 TDS 694C User Manual Using Features for Advanced Applications Whether Zoom is on or off you can press Reset main gt Reset Live Factors or Reset All Factors side to return the zoomed FFT waveform to no magnifi cation 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 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 o
55. Following these descriptions are procedures for selecting the sampling and acquisition modes beginning with Checking the Acquisition Readout on page 3 20 TDS 694C User Manual 3 15 Acquiring and Displaying Waveforms Sampling and Digitizing 3 16 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 7 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 on oN 45 0 V 5 0 V Ea e a j j x OV X o gi J aes S 50V 5 00 Input Signal Sampled Points Digital Values Figure 3 7 Acquisition Input Analog Signal Sample and Digitize The oscilloscope uses the samples it takes see Figure 3 9 to create a waveform 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 8 The digitizer can use any extra samples to perform add
56. Glossary 5 Horizontal POSITION 2 14 3 15 Horizontal SCALE 2 14 3 15 Trigger MAIN LEVEL 2 15 3 45 Vertical POSITION 2 14 3 11 Vertical SCALE 2 14 3 11 L Labelling menu Enter Char 3 126 3 127 Landscape Hardcopy menu 3 132 Laserjet 3 129 Laserjet Hardcopy menu 3 131 Layout Hardcopy menu 3 132 Level Delayed Trigger menu 3 88 Level Main Trigger menu 3 52 3 73 3 77 3 82 Level Trigger 3 45 LF Rej Main Trigger menu 3 51 Lightness Color menu 3 32 Limit Test Condition Met Acquire menu 3 151 Limit Test Setup Acquire menu 3 150 3 151 Limit Test Sources Acquire menu 3 150 Limit Test Acquire menu 3 151 TDS 694C User Manual Limit testing 3 147 Linear interpolation 3 19 3 28 Glossary 6 Linear interpolation Display menu 3 28 Logic trigger 3 43 3 54 Definitions 3 54 Pattern 3 54 Glossary 6 Readout 3 55 State 3 54 Glossary 6 Logic triggering 3 53 Logic Main Trigger menu 3 49 Low 3 91 Glossary 6 Low impedance Zo probes D 2 Low Ref Measure menu 3 97 Lubrication E 2 M Main menu Glossary 7 Main menu buttons 2 3 Glossary 7 Main Scale Horizontal menu 3 16 Main Trigger Menu Falling edge 3 52 Rising edge 3 52 Main Trigger menu 3 49 3 50 3 57 3 61 3 62 3 71 3 73 3 77 AC 3 51 Accept Glitch 3 73 AND 3 59 3 61 Auto 3 51 Ch1 Ch2 3 51 3 58 3 61 3 62 3 72 3 73 3 74 3 76 3 77 3 81 Class 3 76 3
57. Logic Analyzer system trigger will cause the TDS 694C acquisition to jitter several nanoseconds The TLA Logic Analyzer Cross Trigger delay should be adjusted to cause the range of the jitter to be centered around the center graticule position Once this calibration has been completed the record length sample rate and trigger position can all be varied without affecting the relation of the system trigger position indicated on the TLA Logic Analyzer with the trigger position on the TDS 694C indicated by the Display T Trigger Point The TLA Logic Analyzer Cross Trigger delay value is treated as an environmen tal variable similar to GPIB and Hardcopy parameters and will not be changed by recalling setups TDS 694C User Manual Triggering on Waveforms Triggering on Pulses TDS 694C User Manual The TDS 694C Oscilloscopes can trigger on glitch or runt pulses or it can trigger based on the width slew rate or timeout period of a pulse These capabilities make 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 subsection describes how to use each of the five classes of pulse triggers glitch runt width and slew rate and timeout 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 O
58. Managing the File System on page 3 122 Managing the File System 3 122 The TDS 694C Oscilloscopes provides file utilities and a floppy disk drive and optional hard disk for saving hardcopies setups and waveforms This section describes how to manage delete rename etc these files using the file system Read the sections listed under To Find More Information on page 3 127 for information on saving hardcopies setups and waveforms TDS 694C User Manual Saving Waveforms and Setups 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 SAVE RECALL WAVEFORM pop up 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 64 NOTE The amount of free space on the active 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 I 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 64 690 Kbytes x 1024 bytes Kbyte 706 560 bytes Va Tek Run 1 00MS s
59. Manual seconds 3 105 Time Units 3 105 Tracking 3 104 Video Line Number 3 105 Cursor readout H Bars 3 160 3 176 3 181 Paired 3 176 Paired cursors 3 162 3 183 V Bars 3 162 3 176 3 182 Cursors 3 100 Glossary 3 How to use 3 103 with derivative waveforms 3 176 with FFT waveforms 3 160 with integral waveforms 3 181 Cycle area 3 90 Glossary 3 Cycle mean 3 90 Glossary 3 Cycle RMS 3 91 Glossary 3 D Data Source Main Trigger menu 3 62 Date Time On hardcopies 3 132 To set 3 133 DC coupling Glossary 3 DC offset 3 165 for DC correction of FFTs 3 165 with math waveforms 3 165 3 183 DC Main Trigger menu 3 51 Define Inputs Main Trigger menu 3 58 3 61 3 63 Define Logic Main Trigger menu 3 59 3 61 Delay by Events Delayed Trigger menu 3 86 Delay by Time Delayed Trigger menu 3 86 Delay by Delayed Trigger menu 3 86 Delay measurement 3 97 Glossary 3 Delay time Glossary 3 Delay To Measure Delay menu 3 97 Delayed Only Horizontal menu 3 84 Delayed Runs After Main 3 45 Delayed Runs After Main Horizontal menu 3 17 3 84 Delayed Scale Horizontal menu 3 16 DELAYED TRIG button 3 45 3 84 Delayed trigger 3 45 3 82 3 88 How to set up 3 84 Delayed Trigger menu 3 84 3 88 Chl Ch2 3 87 Coupling 3 87 Delay by 3 86 Delay by Events 3 86 Delay by Time 3 86 Falling edge 3 87 Index 3 Index Level 3 88
60. Math Reterence Options Colors lt Color gt Colors CIPO ClO e Figure 3 18 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 3 31 Acquiring and Displaying Waveforms 1 Press the main menu Restore Colors item See Figure 3 19 2 Select the object s you want to restore by pressing Reset Current Palette To Factory Reset All Palettes To Factory Reset Palette on monochrome oscilloscopes or Reset All Mappings To Factory in the side menu Tek Run 100kS 5 Sample Restore Colors Reset Current Palette to Factory Reset All Palettes to Factory Reset All Mappings to Factory Ss00m lt M 500us Chir 270mV pete Palette Change ap ap Restore Settings Math Reference Options H lt Color Normal Colors Colors Colors Colors i LOO Ia OlO Figure 3 19 Display Menu Restore Colors Zooming on Waveforms 3 32 Using with Waveforms The TDS 694C Oscilloscopes can expand or compress zoom in or out on a waveform without changing the acquisition parameters sample rate record
61. Max you may also want to check and or revise reference levels using this side menu Histogram sets the values statistically It selects the most common value 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 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 Then 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 50 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 TDS 694C User Manual Measuring
62. Mode main gt Dual Zoom side to toggle it to ON See Figure 3 22 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 TDS 694C User Manual Acquiring and Displaying Waveforms To Set Dual Zoom Offset TDS 694C User Manual 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 oscilloscope 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 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
63. 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 B ag Table of Contents General Safety Summary cc ccc cece ccc ce eee eescees ix Preface ciere een een a EE EE E E E EE S xi R lated Manuals nce ii iiae tae dae i a ee pee ps pen xi Conventions peiin perede i r ne taiea te Lit a aieia sett xi Getting Started Product Description 0 cece cece cece cece esaa 1 1 TDS094C Features a3 onor Sak aah Siok sais eid area how cotta deren Sieg ids 1 3 Product Specification 0 c cece tte R REE N 1 4 Start Up B32 bial ticle wee lee Retina ei OEE ech RE Oka ER 1 5 Preparation eea tu e plea Se wok ge We Gace Waa ete ed Achim aa E a 1 5 Putting into Servicer does Weds Gone aceite cate E gegen eee E ee 1 5 Operating Basics OVER VICW 5 5525 5 Sie bn ele a dip sie ls woop ies pe sie Be ale ele rd E S 2 1 Operating Interface Maps cc cece cee cece cece ee eeee 2 3 PUtO rial wii easte eee aA ea Sapte dante aare a E tuber sane ee tends 2 9 Example 1 Displaying a Waveform 2 00 eee eee eee eee eee 2 13 Example 2 Displaying Multiple Waveforms 0 0 02 eee
64. 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 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 89 shows how the time domain record is processed TDS 694C User Manual Using Features for Advanced Applications 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 FFT Window O FFT Time Domain Record After Windowing FFT Frequency Domain Record Figure 3 89 Windowing the FFT Time Domain Record Selecting a Window You can select your window to provide better frequency resolution at the expense of better amplitude 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 Hanni
65. Remove a Waveform Tek Run eee Sample JCh Coupli 7 fT eamin Side Menu Title 200mv ch2 100mV M S00us Chit 20 8mV coupling ine scale position Offset Deskew Probe ee my samdiv av as Functions DIGIC IOC C Figure 2 13 The Menus After Changing Channels 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 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 waveform all the CH lights are turned off 2 Press WAVEFORM OFF again to remove the channel waveform Example 3 Taking Automated Measurements Display Measurements 2 20 Automatically The TDS 694C Oscilloscopes 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 To use the automated measurement system you must have a stable display of your signal Also the waveform must have all the segments necessary for the TDS 694C User Manual Tutorial
66. Rising edge 3 87 Set to 50 3 88 Set to ECL 3 88 Set to TTL 3 88 Slope 3 87 Source 3 87 DELAYED TRIGGER OUTPUT BNC 2 5 Delayed Triggerable 3 45 Delayed Triggerable Horizontal menu 3 17 3 86 Delete Refs Save Recall Waveform menu 3 122 Delete File Utilities menu 3 126 Delta Time Main Trigger menu 3 78 Derivative math waveform 3 175 applications 3 174 derivation of 3 175 procedure for displaying 3 175 procedure for measuring 3 176 record length of 3 175 Desk Top Publishing 3 130 Hardcopy 3 117 Deskew 3 111 Glossary 3 Deskew Fixture Connections 2 9 Deskew Vertical menu 3 111 Deskjet 3 129 Deskjet Hardcopy menu 3 131 DeskjetC Hardcopy menu 3 131 Differential active probes D 4 Differentiation of a derivative 3 174 waveform 3 174 Digitizing Glossary 4 Disk How to save a hardcopy to 3 136 Disk drive 3 124 Display 2 6 Hardcopy of 3 129 Options 3 25 3 40 Record View 3 48 System Glossary 4 Display T Trigger Point Display menu 3 27 DISPLAY button 3 25 3 30 Display menu 3 25 3 30 Color 3 30 Contrast 3 26 Cross Hair 3 28 Display 3 25 Display T Trigger Point 3 27 Dots 3 25 Dots style 3 150 Filter 3 28 Frame 3 28 Full 3 28 Graticule 3 28 Index 4 Grid 3 28 Infinite Persistence 3 26 Intensified Samples 3 25 Intensity 3 26 Linear interpolation 3 28 NTSC 3 28 Overall 3
67. See Delayed Triggering on page 3 80 to learn how to use delay 3 43 Triggering on Waveforms Triggering from the Front Panel 3 44 To set MAIN LEVEL Trigger Status Lights To Set to 50 The trigger buttons and knob let you quickly adjust the trigger level or force a trigger See Figure 3 26 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 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 4 TRIGGER MAIN LEVEL O DELAYED TRIG SET LEVEL o fo f O o le x SINGLE TRIG FORCE TRIG Figure 3 26 TRIGGER Controls and Status Lights 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
68. Style Readout Filter Graticule Format Settings Intensity 7 i lt Display gt Vectors leriatace Sin x x Full VF ICC OC O C Figure 3 15 Trigger Point and Level Indicators TDS 694C User Manual 3 25 Acquiring and Displaying Waveforms Select Interpolation Filter Select the Graticule Type 3 26 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 3 130 4 Press Display Date Time side to turn it on or off Push Clear Menu to see the current date and time The display filter types are sin x x interpolation and linear interpolation To switch between interpolation filters DISPLAY gt Settings main gt Display pop up gt Filter main gt Sin x x Interpolation or Linear Interpolation side NOTE When the horizontal scale is set to the faster rates 2 ns div for the TDS 694C 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 interpolation is not used See Interpolation on page 3 17 for a discussion of interpolation To change the graticule Press DISPLAY gt Settings main gt Display pop up gt Graticule main
69. TDS 600C amp TDS 700D Technical Reference Performance Verification and Specifications that is shipped as a standard accessory with the TDS 694C Oscil loscopes TDS 694C User Manual 14 Start Up Preparation Signal Path Compensation Recommended Probes Probe Usage A Putting into Service TDS 694C User Manual Before you use the TDS 694C Oscilloscopes 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 3 108 for a description of and operating information on this feature The TDS 694C Oscilloscopes ships without probes To take advantage of the higher bandwidth of these oscilloscopes order P6249 or P6158 probes For a list of recommended optional accessory probes see Accessory Probes on page A 3 Probes that require a 1 MQ input like the P6139A will not work on the TDS 694C Be sure you use the appropriate probe for the measurement See the User manual for the probe for more information CAUTION Using the P6249 or P6245 Active Probe to measure signals greater than 40 volts may damage the pro
70. User Manual A 6 SE Appendix B Algorithms The TDS 694C Oscilloscopes can take 25 automatic measurements By knowing how it makes these calculations you may better understand how to use your oscilloscope and how to interpret your results Measurement Variables The oscilloscope 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 TDS 694C User Manual B 1 Appendix B Algorithms HighRef MidRef LowRef M
71. You cannot set offset to less than the minimum offset time available when using the general purpose knob 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 Dual Zoom 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 35 3 37 Acquiring and Displaying Waveforms Tek Run Sau Sample oe Time 412 6nS Selected Graticule Zoomed Waveform Edges Zoom Boxes al Zoom Mode Unzoomed Waveform M 100ns chi 78omv a4 off wH E Preview on ou Dual Zoom ON OIOI E E CoD Co Figure 3 22 Dual Zoom Shown Dual Window Preview Mode 3 38 TDS 694C User Manual a ery Triggering on Waveforms Triggering Concepts TDS 694C User Manual To use the TDS 694C Oscilloscopes to measure or monitor waveforms you need to know how to trigger a
72. arithmetic area if Start End then return the interpolated value at Start Otherwise Area End Waveform t dt Start For details of the integration algorithm see page B 15 Amplitude voltage measurement 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 GjoleMeans Waveform t dt StartCycle For details of the integration algorithm see page B 15 TDS 694C User Manual Appendix B Algorithms Burst Width UU Cycle Mean Cycle RMS TDS 694C User Manual Timing measurement The duration of a burst 1 Find MCross1 on the waveform This is MCross Start 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 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 15 The true Root Mean Square voltage over one cycle If StartCycle EndCycle then CycleRMS Waveform Start Otherwise
73. begin a new task and need to start fresh with known default settings Reset the Oscilloscope 1 Press the save recall SETUP button to display the Setup menu See Figure 2 3 SAVE RECALL APPLICATION MENU ACQUIRE MENU AUTOSET WAVEFORM MEASURE HARDCOPY CRUN STOP i a a Sa ae ee ae STATUS UTILITY SHIFT SETUP CURSOR DISPLAY SETUP Buton a aS ip ae ae GED es VERTICAL A HORIZONTAL y Figure 2 3 SETUP Button Location TDS 694C User Manual Tutorial OK Confirm Factory Init Menu Item and Button Recall Factory Setup Menu Item and Button TDS 694C User Manual The oscilloscope displays main menus along the bottom of the screen Figure 2 4 shows the Setup main menu 2 as es e Figure 2 4 The Setup Menu 2 Press the button directly below the Recall Factory Setup menu item 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 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 4 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 sav
74. changed 3 Press Remove Measrmnt main gt All Measurements side That returns the display to its original state 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 displayed 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 2 Press Again side to do another snapshot and update the snapshot measure ments 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 me
75. display check the Channel Reference and Record icons See figures 3 3 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 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 4 TDS 694C User Manual Acquiring and Displaying Waveforms Channel Reference Icon Original Position Positioned Vertically Positioned Horizontally Original Scale Scaled Vertically Scaled Horizontally Figure 3 3 Scaling and Positioning To Change Vertical Scale The TDS 694C Oscilloscopes permits you to change vertical scale and position 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 As you tur
76. eee 2 16 Example 3 Taking Automated Measurements 0 00 eee eee 2 20 Example 4 Saving Setups 0 0 000 ccc eee cee teen eens 2 26 Reference Overview 2955 5 sie hina 2G ese a aie sted wilde wie 8 HS Saas SE waded wales 3 1 Acquiring and Displaying Waveforms eeeeeeeees 3 5 Coupling Waveforms to the Oscilloscope 00 cee eee eee eee 3 5 Setting up Automatically Autoset and Reset 0 00 e ee eeeee 3 6 Selecting Channels snc o oo Ne as sne bn ecto chats bine AEA pete wae eind 3 8 Scaling and Positioning Waveforms 00 cece eee eee eee eee 3 10 Choosing an Acquisition Mode eaaa eee eee 3 17 Customizing the Display 00 0c ccc cee eens 3 25 Customizing the Display Color 0 0 cee cece ce eee eee 3 30 Zooming on Waveforms 0 ccc tcc ene e ene eens 3 34 Triggering on Waveforms cece cece cece eee eeeees 3 41 Triggering Concepts e essee r he eine ieee de ee ede ed Bee eels oe 3 41 Triggering from the Front Panel 00 eee eee cee een eee 3 46 Triggering on a Waveform Edge 0 cece cece een eee 3 49 Triggering Based on Logic 0 0 eee urere rererere 3 53 Triggering on Pulses 2 0 2 0 0 cece tenet A 3 69 Delayed Triggering cx sic sn S eects state tae a Cheha he at ads 3 82 Measuring Waveforms ccccccccsccsccccccescssesees 3 89 Taking Automated Measurements 0 0
77. 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 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 3 171 Using Features for Advanced Applications al hi Rectangular Window Hamming Window ra Hanning Window Blackman Harris Window Figure 3 90 FFT Windows and Bandpass Characteristics Waveform Differentiation The Advanced DSP Math capabilities of the TDS 694C Oscilloscopes 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 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 TDS 694C User Manual 3 172 Using Features for Advanced Applications The math waveform derived from the sampled waveform is computed based on the follow
78. 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 tracking lt o I Only Selected Cursor Moves dy Both Cursors Move in Tandem Figure 3 54 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 55 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 694C User Manual Measuring Waveforms 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 selected cursor relative to ground See Figure 3 56 Tek Run 100kKS 5 Average E Cursor Readout
79. gt Type main Pulse pop up gt Class main Slew Rate pop up gt Trigger When main 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 TDS 694C User Manual 3 76 Triggering on Waveforms TDS 694C User Manual 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 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 Pulse pop up gt Class main gt Slew Rate pop up gt Trigger When main Trigger if Faster Than or Trigger if Slower Than side See Figure 3 41 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 oscilloscop
80. if changing a persistence palette in the side menu 3 If you want to use the factory default for this color or color index 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 3 29 Acquiring and Displaying Waveforms Set Math Waveform Color 3 30 0 blue 60 magenta 120 red 180 yellow 240 green and 300 cyan 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 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 Tek Run 250kS 5 Sample Change Colors Color chi Hue a Lightness 65 BG LChi Cch2 Ch3 Ch4 Math Ref Clsn Saturation a rosino au Tee T Resette Factor Zone Grat Text Scroll ScrTxt Histo colon peter Palette ieirate ap ap Restore Settings 5 Math Reference Options lt Color Normal Colors Colors Colors Colors ClOTO TC C MICIO lM C ao Figure 3 17 Display Menu Palette Colors To define math waveform colors
81. if a printer or Zip drive is attached at power up Changing and then attempting to use the I O device after power up will generate an error message See Saving and Recalling Setups on page 3 115 See Saving and Recalling Waveforms and Acquisitions on page 3 118 See Printing a Hardcopy on page 3 127 The TDS 694C Oscilloscopes can provide 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 disk 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 Color Deskjet inkjet printer m HP Laserjet laser printer m Epson m DPU 411 II portable thermal printer m DPU 412 portable thermal printer m 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 3 127 Saving Waveform
82. installed the Probe Offset Compensation message will replace the Probe Gain Compensa tion message Tek Run es Probe Cal Clear Probe Cal Probe Cal Status initialized Probe Gain Compensation 1 Connect probe to front panel signal outputs labeled Probe Compensation SIGNAL and GND If you are calibrating a current probe connect the calibration adapter to the front panel and the probe to the adapter 2 Press Compensate Gain to proceed OK Press Clear Menu to exit EOmpetisate M 500us Chi DOIDIDIDID DIGIC I O Cla e Figure 3 59 Probe Cal Menu and Gain Compensation Display m 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 m 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 11 If the Probe Offset Compensation message is displayed continue with step 15 otherwise continue with step 12 12 If the Compensation Error message is displayed continue wit
83. 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 35 To read about the two interpolation methods see Interpolation on page 3 17 To differentiate between the real and interpolated samples set the display style to Intensified Samples See Select the Display Style on page 3 23 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 20 on page 3 35 Dual window preview mode does not display the Zoom readout 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 from the More menu 2 Press ZOOM Press ZOOM gt Mode main gt ON side The ZOOM front panel button should light up Toggle Dual Zoom to OFF in the side menu 3 Adjust the vertical zoom factor for the selected waveform using the vertical SCALE kno
84. it off 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 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 TDS 694C User Manual 3 149 Using Features for Advanced Applications Multiple Waveform Comparisons Waveform Math 3 150 You can also compare more than one waveform against a single template or 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 33 for more information on horizontal lock m With horizontal lock set
85. level Typically set to 50 You can set it from 0 to 100 or to a voltage level TDS 694C User Manual Appendix B Algorithms 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 for 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 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 fro
86. menu 5 Verify the word Pass appears under Signal Path in the main menu See Figure 3 58 TDS 694C User Manual Measuring Waveforms Channel Probe Deskew Probe Cal TDS 694C User Manual Tek Run 500kKS 5 Sample Signal Path ompensatio 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 harmed p 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 Input signals OK with AC components Disconnect or otherwise remove these signals prior to running S SPC will take up to 5 minutes to run oltage Frequency ulse System Path Reference Response Trigger lt Cal gt Pass Pass Pass Pass Compensate Signal Paths Oooo oj I 10919 1 1 1 Figure 3 58 Performing a Signal Path Compensation The TDS Oscilloscopes allow you to adjust a relative time delay for each channel This feature lets you align the signals to compensate for the fact that signals may come in from cables of differing lengths The oscilloscope applies deskew values after it completes each acquisition therefore the deskew values do not affect logic triggering Also deskew has no affect on XY display format To set a ch
87. menu choices That channel always matches the lighted channel button Press GND side to toggle the selection to ground GND That changes the input coupling of channel 2 from DC to GND The channel readout for channel 2 near the bottom of the graticule now shows a ground indicator TDS 694C User Manual Tutorial Tek Run eS Sample Ch2 Reference Indicator 1_ ch 200mVv 100mV M 500ps Chis 208mV coupling ine acae position Offset Deskew Probe ers 2 90 div ov as Functions ch2 Coupling Side Menu Title Impedance Oooo o ED CEI Cc C C Figure 2 12 The Vertical Main Menu and Coupling Side Menu 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 already 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 GND channel 2 setting to the DC coupling setting of channel 1 2 Press CH 2 gt DC side to toggle the selection to DC That returns the input coupling of channel 2 to its initial state TDS 694C User Manual 2 19 Tutorial
88. of classes 3 69 Pulse triggers definitions of 3 70 Pulse Main Trigger menu 3 49 3 73 3 76 3 81 Q Quantizing Glossary 9 R Rack mounting A 1 Readout Acquisition 3 22 Channel 2 6 3 8 3 35 Cursors 2 6 Edge trigger 3 49 General purpose knob 2 6 Logic trigger 3 55 Measurement 3 92 3 93 Record view 2 6 Snapshot 3 99 Time base 2 6 Trigger 2 6 3 48 Trigger Level Bar 3 26 Trigger Point 3 26 Readout Cursor Paired 3 176 Readout cursor H Bars 3 160 3 176 3 181 Paired cursors 3 162 3 183 V Bars 3 162 3 176 3 182 Readout Display menu 3 27 3 29 Real time sampling 3 19 Real time sampling Glossary 9 Rear panel 2 5 Recall Setups 3 117 Recall Factory Setup Save Recall Setup menu 3 119 Recall Saved Setup Save Recall Setup menu 3 119 Recalling Acquisitions 3 120 TDS 694C User Manual Waveforms 3 120 Record length 3 16 Glossary 9 derivative math waveforms 3 175 integral math waveforms 3 179 Option 1M A 1 Record Length Horizontal menu 3 16 Record View 2 6 3 10 3 14 3 48 Rectangular window 3 159 Ref Color menu 3 33 Ref1 Ref2 Ref3 Ref4 File Save Recall Waveform menu 3 123 Ref1 Ref2 Ref3 Ref4 Reference waveform status 3 123 Reference Indicator Channel 3 8 Reference levels 2 23 Defining for Measure 3 96 Reference Levels Measure menu 3 96 Reference memory Glossary 9 Reject Gl
89. 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 3 41 Triggering on Waveforms 3 42 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 trigger 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 24 Each pulse looks like any other so many possible trigger points exist 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 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 49 You can also set a default
90. os than the trigger level for the timeout value To Trigger on a 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 Pulse pop up gt Class main Glitch pop up TDS 694C User Manual 3 69 Triggering on Waveforms 3 70 Tek Run ear Sample am 2 Runt Width Slew Rate Timeout i M 300s Glitch chi A Pulse Glitch Source i Eeg oei cich Level oge Type Class 5 amp amp lt Pubse gt lt Glitch gt e width cept 252mV Holdoff 2 CD CD CD Figure 3 39 Main Trigger Menu Glitch Class 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 gt Type main gt Pulse pop up gt Polarity amp Width main gt Positive Negative or Either side Positive looks at positive going
91. 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 less than or equal to the Upper Limit Set the Level Press TRIGGER MENU gt Type main gt Pulse pop up gt Class main Width pop up 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 49 To learn more about trigger mode and holdoff see Trigger Modes and Trigger Holdoff on page 3 41 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 Pulse pop up gt Class main Slew Rate pop up See Figure 3 41 on page 3 78 Select the Source Press TRIGGER MENU gt Type main gt Pulse pop up gt 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 Pulse pop up gt Class main Slew Rate pop up gt Polarity main Positive N
92. pulses Negative looks at negative going pulses Either looks at both positive and negative pulses 2 Press Width side and set the glitch width using the general purpose knob or keypad TDS 694C User Manual Triggering on Waveforms To Trigger on a Runt Pulse TDS 694C User Manual Set to Accept or Reject Glitch To specify whether to trigger on glitches or ignore glitches press TRIGGER MENU Type main gt Pulse pop up gt Class main Glitch pop up gt Glitch main Accept Glitch or Reject Glitch side 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 Level main 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
93. 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 694C Oscillo scopes 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 P6249 connect from the CH 1 connector of the oscilloscope to the PROBE COMPENSATION connectors See Figure 2 2 NOTE See Appendix A Options and Accessories for optional probes you can order and use with this product Use the probe deskew fixture to ensure optimum probe connections P6249 Signal probes Ground a A Figure 2 1 Deskew Fixture Connections two P6249 probes shown TDS 694C User Manual Tutorial oN 1 atl A ME N ie c BO Ce a Deskew fixture gt Figure 2 2 Connecting a Probe for the Examples P6249 shown 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
94. template waveform You set an envelope of limits around a waveform and the oscilloscope finds waveforms that fall outside those limits See Figure 3 78 When it finds such a waveform the oscilloscope can generate a hardcopy ring a bell and stop and wait for your input 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 TDS 694C User Manual 3 145 Using Features for Advanced Applications Figure 3 78 Comparing a Waveform to a Limit Template 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 79 NOTE The template will be smoother if you acquire the template waveform using Average acqui
95. 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 Tek Run ae Sample 1 High Ref 90 _ _ General Level Purpose Setup Knob Icon 3E W e highlighted Menu Item with Boxed Readout Value Li f S am resolution uJ Mid2 Ref 50 200mv i M 3004 chi Ff 208mv more 2 of 2 eer Remove Gating Statistics E ea Measure Measrmnt ae E Snapshot lt measure gt for Chi Measrmnt OFF OFE Histogram SSS Figure 2 16 General Purpose Knob Indicators The Numeric Keypad Any time the general purpose knob is set to adjust a numeric parameter 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 47 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 TDS 694C User Manual Tutorial ea 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
96. 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 a logic analyzer 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 TDS 694C User Manual Triggering on Waveforms Trigger Types Trigger Modes TDS 694C User Manual 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 47 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 five classes of pulse triggers are glitch runt width slew rate and timeout 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
97. 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 gt 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 74 Talk Listen Address 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 3 139 Saving Waveforms and Setups Tek Run 100kKS 5 Sample GPIB Address 1 GPIB Configuration Pt a ia ee as ven t Address Hardcopy Talk Only GPIB Configuration Menu Off Bus Zoomy l C M 500us Chif 248mV Configure System Port ithe lt b O gt lt cpie gt gc
98. 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 2 17 Tutorial 2 18 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 channel one 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 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 Press VERTICAL MENU gt Coupling main The VERTICAL MENU button displays a menu that gives you 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
99. 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 condition 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 ace Amplitude The High waveform value less the Low waveform value TDS 694C User Manual Glossary 1 Glossary 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 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 o
100. trigger indicator trigger level bar and current date and time appear on the display The options also control what style trigger level bar long or short is displayed TDS 694C User Manual Acquiring and Displaying Waveforms 1 Press DISPLAY gt Settings main gt Display pop up gt Readout Options main 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 3 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 15 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 time base The trigger bar is a visual indicator of the trigger level ie 5 Tek Run 50 0kS 5 Sample Readout Options Display T Trigger Point Trigger P oint Indicator Trigger Bar Style tong Trigger Bar Long Style ey ree ric oe fo Eon sol ees l perad 2 7 ay Or Trigger Bar S hort Style 50 0mv MT ooms Chit 6amv Oloo
101. 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 DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
102. use the Level item in the Delayed Trigger menu TDS 694C User Manual Triggering on Waveforms To Force a Trigger To Single Trigger To Check Trigger Status TDS 694C User Manual 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 before the end of pretrigger holdoff However the button has no effect if the acquisition system is stopped 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 20 for further discussion of single sequence acquisitions 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 th
103. window Hanning Very good window for measuring amplitude accuracy but degraded for resolving frequencies Blackman Harris Best window for measuring the amplitude of frequencies but worst at resolving frequencies The topic Selecting a Window on page 3 169 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 3 167 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 84 3 157 Using Features for Advanced Applications Measurements of an FFT 3 158 Tek Run 50 0MS s Sample Ollo thi a0 va ps cht A s00mv 29 Mar 1994 12 08 57 Math 20 0 dB 2 50MHz Dlo aS Figure 3 84 FFT Math Waveform in Math1 To Take Cursor Once you have displayed an FFT math waveform use cursors to measure its 1 frequency amplitude or phase angle Be sure MORE is selected in the channel sele
104. 1 Choose to define math waveform colors by selecting the main menu Map Math item Select one of the three math waveforms by pressing Math in the side menu If you want to assign the selected math waveform to a specific color press Color and cycle through the choices 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 TDS 694C User Manual Acquiring and Displaying Waveforms Set Reference Waveform Color Select Options Restore Colors TDS 694C User Manual To return to the factory defaults select Reset to Factory Color To define reference waveform colors Press Map Reference in the main menu See Figure 3 18 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 j Tek Run 250kS 5 Sample Ref Mappings Ref Refi Color Matches ontents chi Ch2 Ch3 Ch4 Math Color Ref Reset to Factory Color Palette Change ap ap Restore Settings jvormal Colors
105. 1 To Ref2 To Ref3 or To Ref4 side to complete the operation To use autosave Press SAVE RECALL WAVEFORM gt Autosave main Autosave Single Seq ON side Also turn on Single Acquisition Sequence in the Acquire menu See Stop After on page 3 20 To disable this feature simply press Autosave main Autosave Single Seq OFF side 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 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 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 disk file before enabling a single acquisition sequence m Autosave is not available in DPO mode or if Extended Acquisition is On To run file utilities see the
106. 100 MHz Ch 1 Period 10 ns Cursors Figure 3 46 Histogram Graticule Cursor and Automated Measurements TDS 694C User Manual 3 87 Measuring Waveforms Taking Automated Measurements Measurement List The TDS 694C Oscilloscopes provides the feature Measure for automatically taking and displaying waveform measurements This section 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 Automatic measurements are taken over the entire waveform record or if you specify gated measurements see page 3 92 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 97 The TDS 694C Oscilloscope provides you with automatic measurements Table 3 5 lists brief definitions of the automated measurements in the oscilloscope for more details see Appendix B Algorithms page B 1 Table 3 5 Measurement definitions Name tt Amplitude Area Cycle Area J Burst Width ve Cycle Mean 3 88 Definition Voltage measureme
107. 102 page 3 46 knob or keypad fine adjustments C gt Tek Run 10 00GS s Samply Trigger Level 252mV Pada Coarse K a Shows what part of the waveform The waveform Shows what part of record is displayed page 3 12 record icon the acquisition 4 record is in the waveform record x Trigger level on lt _tevel Cursor measurements waveform may be an page 3 98 arrow at right side of screen instead of a bar ea J 252m Set to TTL The side menu with choices of specific actions waveform source Set to ECL Set to 50 Trigger parameters page 3 46 Vertical scale Ca ange page 3 9 Sa ss Type s dge gt Source chi lope Level A e ari af 252mV Holdoff The main menu with Horizontal scale and time choices of major actions base type page 3 13 TDS 694C User Manual 2 6 Operating Interface Maps To Operate a Menu 1 Press front panel menu button Press SHIFT first if button label is blue Tektronix TDS 694C SrA RATE sau oscore KA J APPUCATION g MENU ACQUIRE MEX MEASURE HARDCOPY RUN STOP CO CO umu SFT CURSOR DISPLAY fT LOAA Tek Run 5 00GS s Sample Trigger Level 4mV E F S HORIZONTAL fay I HORIZONTAL MENU am Set to TTL Co
108. 3 109 Minimum 3 91 Glossary 7 Negative duty cycle 3 91 Negative overshoot 3 91 Negative width 3 91 Overshoot Glossary 8 Peak Hits 3 109 TDS 694C User Manual Index Peak to peak 3 91 Glossary 8 Period 3 92 Glossary 8 Phase 3 92 Glossary 8 Pk Pk 3 109 Positive duty cycle 3 92 Positive overshoot 3 92 Positive width 3 92 Propagation delay 3 91 Readout 3 92 3 93 Reference levels 2 23 Rise time 2 22 3 92 Glossary 10 RMS 3 92 Glossary 10 StdDev 3 109 Undershoot Glossary 7 Waveform Count 3 109 Width 2 22 Glossary 7 Glossary 9 Measurement Accuracy Ensuring maximum 3 110 3 111 Measurements Algorithms B 1 Automated 2 20 automated 3 90 Classes of 3 89 Cursor 3 100 Gated 3 94 graticule 3 105 List of automated 3 90 3 109 3 116 Snapshot of 3 99 Measuring Waveforms 3 89 Median 3 109 Memory Waveform 3 122 Menu Acquire 3 22 3 148 Color 3 30 Cursor 3 103 Delayed Trigger 3 84 3 88 Display 3 25 3 30 File Utilities 3 125 Horizontal 3 45 3 84 Main 2 6 Main Trigger 3 49 3 50 3 57 3 61 3 62 3 71 3 73 3 77 Measure 3 93 3 99 More 3 123 3 153 3 157 3 175 See also More menu Operation 2 7 Pop up 2 8 Glossary 8 Save Recall 3 118 Save Recall Waveform 3 121 Setup 2 10 3 8 Status 3 143 Utility 3 23 3 130 Mid Ref Measure menu 3 97 TDS 694C User Manual Mid2 Ref Measure menu 3 97
109. 3 59 3 61 Normal trigger mode 3 43 Glossary 7 Normal Color menu 3 31 Normal Main Trigger menu 3 51 NTSC Display menu 3 28 Nyquist frequency 3 167 O Off Bus Utility menu 3 141 Offset DC See DC Offset Vertical 3 13 vertical 3 165 3 177 3 183 Offset Vertical menu 3 13 OK Confirm Clear Spool Hardcopy menu 3 135 OK Create Math Wfm More menu 3 153 OK Create Measurement Measure Delay menu 3 98 OK Erase Ref amp Panel Memory Utility menu 3 119 OK Store Template Acquire menu 3 149 ON STBY button 1 7 2 3 Optical Power See Mean dBm Optical probes D 5 Options A 1 Options Color menu 3 33 OR Glossary 8 OR Main Trigger menu 3 59 3 61 Oscilloscope Glossary 8 Overall Display menu 3 26 Overshoot Glossary 8 Overwrite Lock File Utilities menu 3 128 P P6205 Active Probe 1 5 Packaging C 1 Paired cursor 3 101 PAL Display menu 3 28 Palette Color menu 3 31 Palette Hardcopy menu 3 132 Passive voltage probes D 1 Pattern trigger 3 53 How to setup 3 57 PCX 3 129 PCX Color Hardcopy menu 3 131 PCX Hardcopy menu 3 131 Peak detect acquisition mode 3 20 Glossary 8 Peak Hits 3 109 Peak to peak 3 91 Glossary 8 Index 10 Period 3 92 Glossary 8 Persistence 3 26 Persistence Palette Color menu 3 31 Phase 3 92 Glossary 8 Phase suppression 3 169 Pixel Glossary 8 Pk Pk 3 109 Polarity and Width Main Trigger menu 3 72 Polarity M
110. 81 Pattern 3 57 Runt 3 73 Setup Hold 3 62 Slew Rate 3 77 State 3 61 Class Glitch 3 71 Clock Source 3 62 Coupling 3 51 Data Source 3 62 DC 3 51 Define Inputs 3 58 3 61 3 63 Define Logic 3 59 3 61 Delta Time 3 78 Edge 3 49 3 50 Either 3 72 3 74 3 77 Falling edge 3 61 3 62 Glitch 3 73 Goes FALSE 3 59 3 61 Goes TRUE 3 59 3 61 HF Rej 3 51 Index 7 Index Level 3 52 3 73 3 77 3 82 LF Rej 3 51 Mode amp Holdoff 3 51 NAND 3 59 3 61 Negative 3 72 3 74 3 77 Noise Rej 3 51 NOR 3 59 3 61 Normal 3 51 OR 3 59 3 61 Polarity 3 74 3 77 Polarity and Width 3 72 Positive 3 72 3 74 3 77 Pulse 3 49 3 73 3 76 3 81 Reject Glitch 3 73 Rising edge 3 61 3 62 Runt 3 73 Set to 50 3 46 3 52 3 73 3 82 Set to ECL 3 52 3 73 3 78 3 82 Set to TTL 3 52 3 73 3 78 3 82 Slope 3 52 Source 3 51 3 72 3 74 3 76 3 77 3 81 State 3 61 3 62 Thresholds 3 74 3 78 Time 3 82 Timeout 3 81 3 82 Trigger When 3 59 3 61 3 78 True for less than 3 59 True for more than 3 59 Type 3 49 3 50 3 76 3 81 Logic 3 57 3 61 3 62 Pulse 3 77 Pulse 3 73 Type Pulse 3 71 Width 3 72 3 76 MAIN TRIGGER OUTPUT BNC 2 5 Map Math Color menu 3 32 Map Reference Color menu 3 33 Math waveform derivative See Derivative math waveform FFT See FFT math waveform integral See Integral math waveform Math waveforms 3
111. 9 8 Min 49 6 J Max 50 4 C1 Over LOJO CJC o ai oim i os Chit A TORM 18 Jan 1999 15 52 25 CQoCocoWwlht Figure 3 47 Measurement Readouts with Statistics Display Measurements 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 perform the following steps see Figure 3 48 1 2 TDS 694C User Manual Press MEASURE gt Select Measrmnt main Select a measurement from the side menu Note the following rules for taking automatic measurements 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 To vary the source for measurements simply select the other channel and then choose the measurements you want Be careful 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 3 91 Measuring Waveforms Remove Measurements Gate Measurements 3 92 Tek Run ei Sample Select Measurement l Frequency Positi widt Negative width EES omn OM 5004s Chi ov more
112. 94C User Manual Using Features for Advanced Applications Offset Position and Scale Record Length TDS 694C User Manual 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 ze
113. A 260mv BICC O O Figure 2 10 The Display After Pressing Autoset Example 2 Displaying Multiple Waveforms The TDS 694C Oscilloscopes 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 694C User Manual Tutorial Add a Waveform TDS 694C User Manual 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 A Gees VERTICAL u J CH3 J CH 4 J MORE MATH REF J CH1 S O CH 2 ENG ZOOM A SCALE zZ M WAVEFORM OFF C 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 waveform to the display 1 Ifyou 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 CH2 The display shows a second waveform which represents the signal on channel 2 Since there is nothing connected to the CH 2 input connector
114. Acquire menu 3 148 Average Acquire menu 3 22 Average More menu 3 155 Bandwidth Glossary 2 Banner displaying 3 145 3 146 Blackman Harris window 3 159 BMP 3 129 BMP Color Hardcopy menu 3 131 BMP Mono Hardcopy menu 3 131 BNC AUX TRIGGER INPUT 2 5 DELAYED TRIGGER OUTPUT 2 5 Index 1 Index MAIN TRIGGER OUTPUT 2 5 Bold Color menu 3 31 Burst width 3 90 Button ACQUIRE MENU 3 22 3 148 AUTOSET 2 15 CLEAR MENU 2 3 2 8 2 13 2 22 2 23 3 98 CURSOR 3 103 DELAYED TRIG 3 45 3 84 DISPLAY 3 25 3 30 FORCE TRIG 3 47 HARDCOPY 3 125 3 131 3 141 HELP 3 145 HORIZONTAL MENU 3 45 3 84 MEASURE 3 93 3 109 MORE 3 9 3 123 3 153 ON STBY 1 7 2 3 Save Recall SETUP 2 10 3 8 3 118 3 125 Save Recall WAVEFORM 3 121 3 125 SELECT 3 104 Glossary 10 SET LEVEL TO 50 3 46 SINGLE TRIG 3 24 3 47 STATUS 3 143 TRIGGER MENU 3 49 3 50 3 57 3 61 3 62 3 71 3 73 3 77 UTILITY 3 23 3 110 3 130 3 141 VERTICAL MENU 2 18 WAVEFORM OFF 2 20 3 9 3 29 ZOOM 3 34 3 35 Buttons CH1 CH2 3 9 Channel selection 2 17 3 9 Main menu 2 3 Side menu 2 3 C Cables 3 140 Cal Probe Vertical menu 3 111 Cart Oscilloscope A 1 Centronics 2 5 Port 3 132 3 139 Centronics port 3 128 CH1 CH2 buttons 3 9 Chl Ch2 Delayed Trigger menu 3 87 Chl Ch2 Main Trigger menu 3 51 3 58 3 61 3 62 3 72 3 73 3 74 3 76 3 77 3 81 Change Colors Color men
115. Ch1 Freq 999 44 HZ chi width 501s chi Rise 7usS Low resolution chi Duty 50 0 i om a 0ps Chi F AEM wa Press to Remove Menus From Screen Figure 2 15 Four Simultaneous Measurement Readouts By default the measurement system will use the 10 and 90 levels of the 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 Level Setup main gt High Ref 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 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 2 23 Tutorial 2 24 Hint To make large changes quickly with the general purpose knob press
116. Delay to Chl E Delay from Selected Wfm Measure writ to 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 Press CLEAR MENU to return to the Measure menu without creating the Delay measurement Asmv OK Create _ Measurement Delay To Edges chi Ee i Oooo oj oaaae eO a Figure 3 51 Measure Delay Menu Delay To The steps just performed select the waveform you want to measure to note that the waveform you are measuring delay from is the selected waveform See Figure 3 51 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 to 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
117. 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 make sure that the Main Trigger menu settings are compatible with Delayed Triggerable and to select that mode do the following steps 1 2 Press TRIGGER MENU 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 If Source is set to Auxiliary press Source main Select any source other than Auxiliary from the side menu according to your application TDS 694C User Manual Triggering on Waveforms F Pretrigger Record Posttrigger Record Delayed Runs After Main Main Tigger Doint lt lt Delayed Trigger Waveform Record gt Main Trigger Source a a rs From Horiz Menu Start Posttrigger Acquisition Delayed Triggerable By Events Main Trigger Point k alk Trigger Waveform Record Main j Trigger Source Delayed N N N N N N N Trigger Source N PS ae as Start P osttrigger Acquisition Trigger Waiting for nth Event on nth Delayed Trigger E vent Where n 5 Delayed Triggerable By Time k pa Trigger Waveform Record gt Main Trigger Point Main Trigger l Source Delayed N N N N N N N Trigger l Sous hk Time Delay
118. Events Wait User specified Time Figure 3 43 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 44 for a more detailed look at how delayed records are placed in time relative to the main trigger 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 3 81 Triggering on Waveforms 3 82 To Run After Delay To Trigger 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 Delayed Only side gt Delayed Runs After Main side Use the general purpose knob or the keypad to set the delay time If you press Intensified side you display an intensified zone on the main timebase record that shows where the delayed timebase record occurs relative to the main trigger For
119. GHOooooea S Oloo Figure 3 74 Utility Menu To Find More Information See Printing a Hardcopy on page 3 127 See the TDS Programmer Manual disk TDS 694C User Manual 3 140 em iP a E Determining Status and Accessing Help Displaying Status TDS 694C User Manual The TDS 694C Oscilloscopes can display the status of its internal systems It also provides an on 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 To display the status of the internal systems perform the following steps 1 Press SHIFT STATUS gt Status main 2 Select a status snapshot from the side menu System displays information about the Horizontal Zoom Acquisition Measure and Hardcopy systems See Figure 3 75 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 Histogram displays information about histograms 3 141 Determining Status and Accessing Help Firmware Version 3 142
120. KPROBE 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 60 If the Re use Probe Calibration data menu is displayed you can choose one of the following options Press OK Use Existing Data side to use the Probe Cal data last stored to compensate the probe Press OK Erase Probe Cal Data side to erase the Probe Cal data last stored and use the probe uncompensated Press CLEAR MENU on the front panel to retain the Probe Cal data last stored and use the probe uncompensated Tek Running 100kS 5 Sample Re use Probe Cal OK Use Existing Cal Data e 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 Oe ois cal Data chi 1 00 V T 00 M 500ps Chi F
121. Layout main gt Landscape or Portrait side See Figure 3 67 Landscape Format Portrait Format Figure 3 67 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 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 a disk drive as the destination for hardcopies See To Save to a Disk on page 3 134 The disk drive can be either the floppy disk drive a hard disk optional or a Zip drive When a Zip drive is attached File is selected and Centronics is grayed out 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 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 Press Clear Menu to remove the menu from the display so the date and time can be displayed See Figure 3 68 The date a
122. M50 0ns Chis 208mv more lofts Am ri Measure WACEGIILS lt Measure gt BALIRA 19109 19 1 1 1 OIl Remove Measrmnt Gating OFF Statistics Level Setu OFF Histogram Stapshot Figure 3 28 Record View Trigger Position and Trigger Level Bar Readouts 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 Edge Logic or Pulse pop up Triggering on a Waveform Edge To Check Edge Trigger Status TDS 694C User Manual The TDS 694C Oscilloscopes 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 to use edge triggering 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 quickly check if edge triggers are selected check the Trigger readout When edge triggers are selected the trigger readout displays the trigger source as well as the trigger slope and level See Figure 3 29 3 47 Triggering on Waveforms To Select Edge Triggering 3 48 Main Trigger Slope Rising Edge
123. Manual 3 55 Triggering on Waveforms Tek Run 100kS s Sample 4 Logic Pattern Inputs e Pulse jommy i M 500s Pattern HXXX D LOJO OC C O it ee rigger Reena Type Class ial a uts i when hresholds amp lt tagic gt lt Pattern gt Goes TRUE Holdoff a Figure 3 33 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 Ch4 side 2 Repeatedly press each input selected in step 1 to choose either High H Low L or Don t Care X for each channel see Figure 3 33 To 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 Pattern pop up gt Set Thresholds main gt Ch1 Ch2 Ch3 or Ch4 side 2 Use the MAIN TRIGGER LEVEL knob the general purpose knob or the keypad to set each threshold TDS 694C User Manual 3 56 Triggering on Waveforms To Define the Logic To choose the logic function you want applied to the input channels see page 3 52 for definitions of the logic functions for both pattern and state triggers Press TRIGGER MENU gt Type main Logic pop up gt Class main
124. N knob positions waveforms more quickly A HORIZONTAL lt JPosition gt HORIZONTAL MENU lt SCALE p gt Figure 3 6 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 the knob scales only the selected waveform 3 13 Acquiring and Displaying Waveforms 3 14 To Change Horizontal Parameters 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 33 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 Trigger Position The trigger point marks time zero in a waveform or acquisition in Extended Acquisition mode record All record points before the trigger event make up the pretrigger portion of the record Every record point after the trigger event is part of the posttrigger portion All timing measurements in the 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 k
125. Pulse pop up gt Class main 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 width you set Enter the width using the general purpose knob or keypad Set the Thresholds To set the two threshold levels used in detecting a runt pulse 1 Press TRIGGER MENU gt Type main Pulse pop up gt Class main Runt pop up gt Thresholds main 2 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 train press DISPLAY Readout Options main Trigger Bar Style side until Long appears in that menu item TDS 694C User Manual Triggering on Waveforms Tek Run euaaar Sample Runt High Threshold 3 00 V Pulse Runt Thresholds Selected trigger bar at upper threshold Unselected trigger bar at lower threshold Dok i Set to TTL noe os D A Set to ECL Runt Pulse Crosses First Threshold aih i Only Recrosses First Threshold a E ce fam 1 width T M50 0ns Runt Chi Level and Triggers Acquisition o Slew Rate oe re Timeout REES RTE EEEE ta de ci i ta BAREA Source Polarity rpger hreshold oce epics Sunis chi Positive Occurs Sara Hoidoff Kea oe
126. S 694C Digital Real Time Oscilloscope is a superb tool for acquiring displaying and measuring waveforms Its performance addresses the needs of both benchtop lab and portable applications with the following key features m An analog bandwidth of 3 GHz simultaneous on 4 channels m A maximum sample rate of up to 10 GS s simultaneous on 4 channels m Records lengths up to 120 K m Upto 29 automatic measurements and measurement statistics see Taking Automated Measurements on page 3 88 m 1 DC vertical gain accuracy see TDS 500D TDS600B amp TDS 700D Technical Reference manual m Internal floppy disk storage and compatible with Iomega 100 Mbyte Zip drive see Saving Waveforms and Setups on page 3 115 m Optional internal hard drive m Trigger modes include edge logic pulse delay modes see Triggering on Waveforms on page 3 39 m Java application support m TLA 700 Logic Analyzer cross triggering support TDS 694C User Manual Product Description Advanced features include limit testing see Limit Testing on page 3 145 FFT see Fast Fourier Transforms on page 3 153 waveform differentiation and integrations see Waveform Differentiation and Waveform Integration starting on page 3 172 waveform histograms see Displaying Histograms on page 3 104 Adjustable channel deskew for increased measurement accuracy see Channel Probe Deskew on page 3 109 Full GPIB programmability see Communicating with Remote Instruments on p
127. Sample Use to 0 fd0 DIR oH eca Saved Setup choose Directory fd0 TEKOOO02 SET TEKOOO00 IMG TEKO0001 IMG TEKOO0003 IMG ave Current Setup cal Factory Setup JB aE Press SELECT to change E E Free SS8KE 96 12 10 96 12 10 97 04 01 97 04 01 97 04 01 File Utilities 10 09 00 Delete Rename more 1of2 File utilities CD C Figure 3 64 File Utilities TDS 694C User Manual LOJO OC C O 3 123 Saving Waveforms and Setups To Delete EA To Rename 3 124 To delete a file or directory turn the general purpose knob until it scrolls the cursor over the line marked with both the name of the file or directory to delete and the file icon or directory icon as shown to the left of this page Then press the side menu Delete button To delete all files in the file list set the cursor to the selection The oscilloscope deletes directories recursively That means it deletes both the directories and all their contents 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 65 The labeling menu should appear Turn the general purpose knob or use the main menu arrow key
128. Shipment cece eeee Appendix D Probe Selection cc cece cece cere eee eeee Appendix E Inspection and Cleaning 0 cece ee eee Appendix F Programmer Disk 0 ce ceee cece ree eeee A 1 B 1 C 1 D 1 E 1 F 1 TDS 694C User Manual Table of Contents List of Figures TDS 694C User Manual Figure 1 1 Rear Panel Controls Used in Start Up 1 7 Figure 1 2 ON STBY Button cc ccc cece ccc e ce eeeees 1 8 Figure 2 1 Deskew Fixture Connections two P6249 probes Shown cece ccc cece ccs cceceecs 2 9 Figure 2 2 Connecting a Probe for the Examples P6249 SHOW o secretasen Steud B Oia ow Sieve ew wialauore eee 2 10 Figure 2 3 SETUP Button Location cccce sce eceees 2 10 Figure 2 4 The Setup Menu ccc cece cece ccc ccscceces 2 11 Figure 2 5 Trigger Controls ccc ccc cc ccc ce ccs cceees 2 12 Figure 2 6 The Display After Factory Initialization 2 13 Figure 2 7 The VERTICAL and HORIZONTAL Controls 2 14 Figure 2 8 TRIGGER Controls ccc cece e ce eee eeeees 2 15 Figure 2 9 AUTOSET Button Location 0c cece eee 2 16 Figure 2 10 The Display After Pressing Autoset 2 16 Figure 2 11 The Channel Buttons and Lights 2 17 Figure 2 12 The Vertical Main Menu and Coupling Side Menu sccocesccuois eee itoni dik as ob Mem ee as Se wild 6 2 19 Fi
129. TDS 694C User Manual 3 167 Using Features for Advanced Applications FFT Windows 3 168 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 3 155 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 the 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
130. 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 measurement press CLEAR MENU which returns you to the Measure menu TDS 694C User Manual Measuring Waveforms 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 5 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 52 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 Zz Tek Run 100KS s5 Sample Snapshot Rit
131. User Manual Tektronix S TDS 694C Digital Real Time Oscilloscope 071 0473 00 This document supports firmware version 1 0 and above Copyright Tektronix Inc 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 and TEK 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 in exchange for the defective product In order to obtain service
132. User Manual 3 61 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 3 62 Advanced Logic Triggering with a TLA Logic Analyzer Tek Run 5 00GS 5 Average Hold Time 30 0ns Setup Hold Times a oe Setup Time ae 10 08 i C122 Diy Hold Time eel fas pls sh 10 54ns 4 1 00 V Ch2 00 H M 10 0ns StHId i ai gee sour Bag Levels lt fLogic gt lt Sthid gt Cch2 Times Holdoff OOGO Figure 3 35 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 31 on page 3 54 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 49 To learn more about trigger mode and holdoff see the descrip
133. Waveforms mA Take a Delay Measurement TDS 694C User Manual Tek Run yen Sample Level Setup Histogram best for pulses Min Max all other waveforms Set Levels in 2 E units 1of2 mee Remove Gating Statistics Eta Measure Measrmnt jc P Snapshot lt measure gt for Chl Measrmnt OFF OFF Histogram LOIDID OI ca 200mv q M 500s Chis 336mv more Kens es oe es aoao Figure 3 50 Measure Menu Reference Levels 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 Mid2 Ref Sets the middle reference level used on the second waveform specified in the Delay or Phase Measurements The default is 50 The delay measurement lets you measure from an edge on the selected waveform 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 3 95 Measuring Waveforms 3 96 Tek Run 100kKS 5 asure
134. XY Display menu 3 29 XYZ format Glossary 12 Y YT Format 3 29 YT format Glossary 12 YT Display menu 3 29 Z Zero phase reference point 3 163 3 168 TDS 694C User Manual establishing for impulse testing 3 168 3 169 3 170 Zip drives 3 128 Glossary 12 Zoom 3 34 3 40 And interpolation 3 35 And waveforms 3 34 derivative math waveforms 3 178 Dual Window mode 3 37 Dual Zoom 3 38 Dual Zoom Offset 3 39 on FFT math waveforms 3 166 on integral math waveforms 3 184 ZOOM button 3 35 Zoom feature 3 34 Zoom menu Dual Zoom 3 38 Dual Zoom Offset 3 39 Preview 3 37 Reset Zoom Factors 3 37 Index 15 Index TDS 694C User Manual Index 16
135. a measurement on another channel select that channel and then select the measurement 2 21 Tutorial Tek Run 100kKS s Select Measurement Frequency Positi widt Negative width 200mv M 500s Chi 248mv eae iene Remove Gating Statistics fais Setu Measure EEG ia A Snapshot lt Measure gt mae Measrmnt OFF OFF Histogram Oooo o Figure 2 14 Measure Main Menu and Select Measurement Side Menu 7 Press Positive Width side gt more side gt Rise Time side gt Pa 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 area press CLEAR MENU See Figure 2 15 Remove Measurement Use the Measure menu to remove measurements you no longer want To remove Readouts a 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 TDS 694C User Manual 2 22 Tutorial Change the Measurement Reference Levels a TDS 694C User Manual Tek Run 100kKS 5 Sample
136. 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 D 3 Appendix D Probe Selection High Speed Active Probes Differential Probes Fixtured Active Probes Current Probes D 4 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 Tektronix P6249 active probe has a dynamic range of 1 74 V 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 designed to be used with 50 Q inputs The same characteristics that apply to active probes apply to active differential 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 precisely connect your instrument to your dev
137. adout Options 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 the point See Choose a Palette on page 3 29 Infinite Persistence style accumulates the record points until you change some control such as scale factor causing the display to be erased Tek Run 100kS s Hi Res i Display Style 7 m vectors 4 Dots Intensified Samples Infinite Persistence 2a0mv TOM S0ous chi 264mv pyatiable a Style Readout Filter Graticule Settings wen Intensity 7 i lt Display gt Vectors Options Sin x x Full PID ICI lO O O O OID CIC aD Figure 3 14 Display Menu Style Intensity lets you set text graticule and waveform intensity brightness levels To set the intensity Press DISPLAY gt Settings main gt Display pop up gt 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 Readout options control whether the
138. age 3 137 and the TDS Family Programmer Manual disk Wide array of probing solutions see Accessory Probes on page 0 3 and Probe Selection on page 0 1 CE FCC UL and CAN CSE compliant see TDS 500D TDS600B amp TDS 700D Technical Reference manual All 4 channels have 8 bit resolution See Table 1 1 on page 1 3 Dual Window Zoom which shows a waveform magnified and unmagnified on the same display see Using Dual Window Mode on page 3 35 Sample envelope average and peak detect modes see Table 1 1 on page 1 3 TDS 694C User Manual Product Description TDS 694C Features Table 1 1 lists some key TDS 694C features that are covered in this manual Table 1 1 Key Features of TDS 694C Feature TDS 694C No of channels 4 Digitizing rate max 10 GS s No of Channels maximum rate 4 Analog Bandwidth 3 GHz Record Lengths max To 120 K Channel Advanced DSP Math Std 2 Storage Floppy Disk Std 2 1 0 includes RS 232 and Centronics Std 2 iomega Zip Drive support Std 2 Input Impedance 50 Q only 1 Advanced digital signal processing provides FFTs integrals and derivatives of waveforms See Option 2F on page 0 2 2 Std denotes a standard product feature as opposed to a feature included as part of an option 3 GPIB I O included with all models TDS 694C User Manual Product Description Product Specification The product specification is found in the technical reference TDS 500D
139. ain Trigger menu 3 74 3 77 Pop up menu 2 8 Glossary 8 Port Hardcopy menu 3 132 Port Utility menu 3 141 Portrait Hardcopy menu 3 132 Position Vertical 3 12 vertical 3 165 3 177 3 183 Position Vertical menu 3 13 Positive duty cycle 3 92 Positive overshoot 3 92 Positive width 3 92 Positive Main Trigger menu 3 72 3 74 3 77 Postscript 3 129 Posttrigger Glossary 9 Power connector 1 7 2 5 Power cords A 1 Power off 1 8 Power on 1 7 Pretrigger Glossary 9 Preview Zoom menu 3 37 Principal power switch 1 7 2 5 Print File Utilities menu 3 127 Printers 3 128 Printing a Hardcopy Reference Article 3 129 Probe Cal 3 111 Probe usage 1 5 Probe channel deskew 3 111 Glossary 3 Probes Accessories A 3 Active voltage D 3 Compensation Glossary 9 Compensation Signal 2 14 Connection 2 9 Current D 4 Definition Glossary 9 Differential active D 4 Fixtured active D 4 General purpose high input resistance D 1 High speed D 4 High voltage D 2 Low impedance Zo D 2 Optical D 5 Option 31 to add A 1 Option 33 to add A 1 TDS 694C User Manual Index Option 37 to add A 1 Option 38 to add A 1 Option 39 to add A 1 P6205 Active 1 5 Passive voltage D 1 Selection D 1 Procedures Inspection and Cleaning E E 2 Programmer manual F 1 Programming GPIB F 1 Programming Examples F Propagation delay 3 91 Pulse trigger 3 43 3 69 definition
140. al Index Spectral 3 31 Temperature 3 31 View Palette 3 31 Color Color menu 3 31 3 32 3 33 Color Display menu 3 30 Compare Ch1 to Acquire menu 3 150 Compare Ch2 to Acquire menu 3 150 Compare Ch3 to Acquire menu 3 150 Compare Ch4 to Acquire menu 3 150 Compare Mathi to Acquire menu 3 150 Compare Math2 to Acquire menu 3 150 Compare Math3 to Acquire menu 3 150 Configure Utility menu 3 23 3 130 3 141 Confirm Delete File Utilities menu 3 127 Connector AUX TRIGGER INPUT 2 5 Centronics 2 5 DELAYED TRIGGER OUTPUT 2 5 GPIB 2 5 3 140 MAIN TRIGGER OUTPUT 2 5 Power 2 5 RS 232 2 5 VGA 2 5 Contrast Display menu 3 26 Conventions xi Copy File Utilities menu 3 127 Coupling 2 18 Ground Glossary 5 Selecting 3 13 Trigger 3 44 Coupling Waveforms 3 5 Coupling Delayed Trigger menu 3 87 Coupling Main Trigger menu 3 51 Coupling Vertical menu 3 13 Create Directory File Utilities menu 3 127 Create Limit Test Template Acquire menu 3 148 Create Measrmnt Measure Delay menu 3 98 Cross Hair Display menu 3 28 Current probes D 4 Cursor Horizontal bar 3 101 Measurements 3 100 modes 3 101 Paired 3 101 readout 3 102 Setting adjustment response speed 3 105 Vertical bar 3 101 CURSOR button 3 103 Cursor menu 3 103 3 160 3 181 1 seconds Hz 3 105 Function 3 103 3 104 H Bars 3 103 3 104 Independent 3 104 TDS 694C User
141. al 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 You can select the Hardcopy Preview palette when using certain color hardcopy formats The default colors in the this palette comprise a white back ground 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 Hue is not available on monochrome oscilloscopes 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 Saturation is not available on monochrome oscilloscopes 1 Color oscilloscopes Select the main menu Change Colors item See Figure 3 17 If changing the colors of a persistence palette press Palette main gt Persistence Palettes side gt View Palette main Then select the palette you want to change from the side menu and select the main menu Change Colors for item 2 Select one of the colors by pressing repeatedly Color Color Index
142. al 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 listing 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 xi of Preface before reading about these tasks Each topic just listed comprises more basic operation tasks and topics A list of these tasks follows TDS 694C User Manual Overview Acquiring and Displaying Coupling Waveforms to the Osc
143. all Waveform menu 3 122 Save Waveform Save Recall Waveform menu 3 121 Save Recall SETUP button 2 10 3 8 3 118 3 125 Save Recall Setup menu 3 118 factory status 3 118 File Utilities 3 120 Recall Factory Setup 3 119 Recall Saved Setup 3 119 Save Current Setup 3 118 Select Application 3 120 user status 3 118 Save Recall WAVEFORM button 3 121 3 125 Save Recall Waveform menu 3 121 active status 3 121 Autosave 3 124 Delete Refs 3 122 empty status 3 121 File Utilities 3 124 Ref1 Ref2 Ref3 Ref4 File 3 123 Save Format 3 122 Save Waveform 3 121 Saving Acquisitions 3 120 Waveforms 3 120 Saving and recalling acquisitions 3 120 Saving and recalling setups 2 26 3 117 Saving and recalling waveforms 3 120 Saving Waveforms and Setups 3 117 Scale vertical 3 165 3 177 3 183 seconds Cursor menu 3 105 Security bracket 2 5 Select Application Save Recall Setup menu 3 120 SELECT button 3 104 Glossary 10 Select Measrmnt Measure menu 3 93 3 97 3 109 Selected waveform Glossary 10 Self test 1 8 Serial number 2 5 Set 1st Source to More menu 3 154 Set 2nd Source to More menu 3 154 Set Function to More menu 3 153 SET LEVEL TO 50 button 3 46 Set Levels in units Measure menu 3 96 Set operator to More menu 3 154 Index 12 Set Single Source to More menu 3 153 3 154 Set Thresholds Main Trigger menu 3 58 3 61 Set to 10 Horizontal menu 3 17 Set to 50 Dela
144. als 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 Instruction steps are numbered The number is omitted if there is only one step When steps require that you make a sequence of selections using front panel controls and menu buttons an arrow 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 in instructions that are graphically intuitive and simplifies procedures For example the instruction just given replaces these five steps 1 B see a 5 Press the front panel button VERTICAL MENU Press the main menu button Coupling Press the side menu button DC Press the main menu button Bandwidth 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 TDS 694C User Manual E Product Description The Tektronix TD
145. an the timeout value TDS 694C User Manual 3 79 Triggering on Waveforms Delayed Triggering 3 80 Either causes a trigger to occur if the signal stays lower or stays higher than the trigger level for longer than the timeout value Time To set the timeout time 1 Press TRIGGER MENU gt Type main Pulse pop up gt Class main Timeout pop up gt Time main 2 Turn the general purpose knob or use the keypad to set values for the timeout time Set the Level Press TRIGGER MENU gt Type main Pulse pop up gt Class main Timeout 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 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 49 To learn more about trigger mode and holdoff see Trigger Modes and Trigger Holdoff on page 3 41 The TDS 694C Oscilloscopes provides a main time base a
146. annel probe deskew do the following steps m Press VERTICAL MENU gt Deskew main m Then use the general purpose knob or the keypad to set the deskew time You can also eliminate any deskew setting by pressing Set to 0 S side The TDS 694C Oscilloscopes 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 oscilloscope 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 probe since the last Probe Cal was performed 3 109 Measuring Waveforms 3 110 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 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 P6249 or P6245 there are no prerequisites to performing this procedure Start a
147. 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 track 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 The TDS 694C Oscilloscopes 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 3 153 Waveform Differ entiation on page 3 172 and Waveform Integration on page 3 177 for informa tion on Advanced DSP Math features TDS 694C User Manual Using Features for Advanced Applications To Use Single Wfm Math To perform waveform math use the More menu Figure 3 80 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 s
148. ate the setup hold violation zone so it spans the clocking edge See the top waveform in Figure 3 31 The oscilloscope detects and triggers on data that 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 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 waveforms of Figure 3 31 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 the hold time setting to no more than 2 5 ns less than one half the clock period hold time lt period 2 2 5 ns or the oscilloscope cannot trigger this assumes a 50 duty cycle clock 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 StHld Setup Hold See Fig ure 3 32 3 53 Triggering on Waveforms Setup Hold Ts Setup Time Violation gt Ty Hold Time Zone Setup Hold Violation Zone Ts Ty aes Ts Ty mustbe 2ns e gt Clock Level Clock Signal Setup Hold lt Violation gt T Zone e Ty o gt Clock Level Clock Signal Setup Hold lt Violation
149. ay check the record view at the top of the display See Figure 3 28 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 28 shows the trigger point indicator and trigger level bar Both the trigger point indicator and level bar are displayed from the Display menu See Set Display Readout Options on page 3 24 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 Trigger side TDS 694C User Manual Triggering on Waveforms Trigger Position Relative to the Display and Waveform Record Trigger Point Indicator Tek Run 1 00GS5 s am Select Measurement Period Indicating the Trigger Position on the Waveform Record Trigger Bar Indicating the Trigger Frequency Positive width Negative width Level on the Waveform R ecord Trigger Menu 200mva q
150. azard 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 Symbols on the Product The following symbols may appear on the product A A gB CAUTION WARNING Double Protective Ground Refer to Manual High Voltage Insulated Earth Terminal Acquisition circuitry in the TDS 694C is very susceptible to damage from electrostatic discharge and from overdrive signals To prevent electrostatic damage to the TDS 694C be sure to operate the oscilloscope only in a static controlled environment Be sure to discharge to ground any electrostatic charge that may be present on cables and probes before attaching them to the oscilloscope To prevent damage from electrostatic discharge install short circuit terminations on unused input connectors Always use a wrist strap with internal impedance provided with your instrument when handling your oscilloscope or making connections TDS 694C User Manual Preface Related Manuals Conventions TDS 694C User Manual This is the User Manual for the TDS 694C Oscilloscopes The chapter Getting Started briefly describes the TDS 694C Oscilloscopes 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 tutor
151. b Adjust the vertical position of the zoomed waveform using the vertical POSITION knob 3 33 Acquiring and Displaying Waveforms 3 34 4 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 20 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 5 Press ZOOM gt Lock main gt AIl Live or None side 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 4 on page 3 34 TDS 694C User Manual Acquiring and Displaying Waveforms Only the selected waveform the top one changes size Set Interpolation Reset Zoom Using Dual Window Mode TDS 694C User Manua
152. be Using the P6158 Voltage Divider Probe to measure signals greater than 22 Vrms may damage the probe To learn how to install access the front panel power on do a self test and power off the oscilloscope do the following procedures Start Up 16 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 500D TDS 600C amp TDS 700D Technical Reference Performance Verification and Specifications Technical Reference Perfor mance Verification and Specifications manual Tektronix part number 071 0496 xx CAUTION To prevent damage to the instrument caused by over heating the TDS 694C must have adequate airflow Verify air intake and exhaust ventilation in the cabinet as specified in Step 2 Leave space for cooling for both rackmount and bench configurations Do this by verifying that the air intake and exhaust holes on the sides and bottom of the cabinet are free of any airflow obstructions Leave at least 5 1 cm 2 inches free on both sides Leave 2 5 cm 1 0 inch minimum space on the bottom of rackmount instruments the height of the feet will provide adequate space for bench configurations WARNING To avoid electrical shock be sure that the power cord is disconnected before checking the fuse 3 Ch
153. c 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 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 in 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 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 opt
154. cccecccceees 3 58 Figure 3 34 Logic Trigger Menu Time Qualified TRUE 3 60 Figure 3 35 Triggering on a Setup Hold Time Violation 3 64 Figure 3 36 TLA 714 to TDS 694C ccc cece ce ee ee eee 3 66 Figure 3 37 TLA 720 to TDS 694C cc cece ew ew ee ee eee 3 66 Figure 3 38 Pulse Trigger Readouts ccceccecscceces 3 70 Figure 3 39 Main Trigger Menu Glitch Class 3 72 Figure 3 40 Main Trigger Menu Runt Class 3 75 Figure 3 41 Main Trigger Menu Slew Rate Class 3 80 Figure 3 42 Delayed Runs After Main cece ewes 3 83 Figure 3 43 Delayed Triggerable cccceccscscceces 3 83 Figure 3 44 How the Delayed Triggers Work 205 3 85 Figure 3 45 Delayed Trigger Menu ccceccecscceces 3 87 TDS 694C User Manual Table of Contents TDS 694C User Manual Figure 3 46 Histogram Graticule Cursor and Automated Measurements cccccccccccccccccevcece 3 89 Figure 3 47 Measurement Readouts with Statistics 3 93 Figure 3 48 Measure Menu cccceccccccccsccscecces 3 94 Figure 3 49 Measure Menu Gating ccc cess eeeees 3 95 Figure 3 50 Measure Menu Reference Levels 3 97 Figure 3 51 Measure Delay Menu Delay To 3 98 Figure 3 52 Snapshot Menu and Readout eeeeee0e 3 99 Figure 3 53 Cursor Types
155. ceeeeeees 3 140 Figure 3 73 Connecting the Oscilloscope to a Controller 3 141 Figure 3 74 Utility Menu cece cc ecw cece eee eeeene 3 142 Figure 3 75 Status Menu System ccceccecscceeee 3 144 Figure 3 76 Banner Display ccccccceccccccsccces 3 145 Figure 3 77 Initial Help Screen 0 cc cece cece eee eeee 3 146 Figure 3 78 Comparing a Waveform to a Limit Template 3 148 Figure 3 79 Acquire Menu Create Limit Test Template 3 149 Figure 3 80 More Menu cece cece cece cece cree eens 3 153 Figure 3 81 Dual Waveform Math Main and Side Menus 3 154 Table of Contents vi Figure 3 82 System Response to an Impulse 206 3 157 Figure 3 83 Define FFT Waveform Menu 0eeeee 3 158 Figure 3 84 FFT Math Waveform in Math 66 3 160 Figure 3 85 Cursor Measurement of an FFT Waveform 3 161 Figure 3 86 Waveform Record vs FFT Time Domain Record 3 163 Figure 3 87 FFT Time Domain Record vs FFT Frequency Domain R cord ss ois soe oie8 Soe eeiee oes paws se o wile Oooo 3 164 Figure 3 88 How Aliased Frequencies Appear in an FFT 3 168 Figure 3 89 Windowing the FFT Time Domain Record 3 171 Figure 3 90 FFT Windows and Bandpass Characteristics 3 174 Figure 3 91 Derivative Math Waveform eeeeeeeee 3 176 Figure 3 92 Peak Peak Amplitude Measurement of a Derivat
156. ci fied lower and upper time limits 3 68 TDS 694C User Manual Triggering on Waveforms Table 3 4 Pulse trigger definitions cont Name Definition Slew positive 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 at a rate faster or slower than user specifies the user specified slew rate for triggering to occur Slew negative 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 ae Slew either 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 at a rate faster or slower than user specifies the user specified slew rate for triggering to occur _ Timeout stays high Triggering occurs if the signal stays higher than the trigger wD level for longer than the timeout value 1 Timeout stays low Triggering occurs if the signal stays lower than the trigger level for longer than the timeout value Timeout either Triggering occurs if the signal stays higher or stays lower
157. ct the floppy disk or the hard disk optional turn the general purpose knob until it scrolls the cursor over the line marked with both the name of the drive to select fd0 hdO or Zip and the disk drive icon pictured at left Then press SELECT To format a 720 Kbyte or 1 44 Mbyte floppy disk or the optional hard disk turn the general purpose knob until it scrolls the cursor over the line marked with both the name of the drive to format fd0 or hd0 and the disk drive icon pictured at left Then press the side menu Format button To format a Zip drive attach it to a compatible PC and use Iomega tools You can use an Iomega Zip drive to save and recall waveforms and hardcopies When a Zip drive is attached to the Centronics port the Centronics port is not available to printers and is grayed out in menus To attach a Zip drive to the Centronics parallel port do the following steps 1 Power down the oscilloscope 2 Ifa printer is attached to the parallel port disconnect the printer 3 Attach a parallel port compatible Zip drive to the Centronics port for the location of the port see the figure on page 2 5 4 Power up the Zip drive either immediately after or at the same time the oscilloscope is powered up Do not power up the Zip drive first TDS 694C User Manual Saving Waveforms and Setups To Find More Information Printing a Hardcopy Supported Formats TDS 694C User Manual The oscilloscope determines
158. ction buttons and that the FFT math waveform is selected in the 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 TDS 694C User Manual Using Features for Advanced Applications Figure 3 85 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 3 156 for more informati
159. d low ref values are needed as in fall time and rise time 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 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 Glossary 5 Glossary S Glossary 6 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 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 f
160. d 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 24 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 45 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 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 menu You will still need to display the Horizontal menu if you want to leave Delayed Triggerable The Source menu lets you select which input will be the delayed trigger source TDS 694C User Manual Triggering on Waveforms TDS 694C User Manual Tek Run 50 0MS s Sample Delay by Time 16ns Delayed Edge Delay i set Triggerable after Time ss Irene Events Saat PA Events Time Time a 200m Cch2 gt soom M 200us Chis 304mvV Events D1 00us Chi 304mv 2 Delay by Source Coupling Slope Leve
161. d 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 5 ns The oscilloscope then interpolates to create the intervening points in the waveform record There are two options for interpolation linear or sin x x Linear interpolation computes record points 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 The TDS 694C oscilloscope supports the following four acquisition modes Sample Envelope Average and Peak Detect Sample the mode most commonly used Peak Detect 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 3 17 Acquiring and Displaying Waveforms 3 18 acquisitions the oscilloscope averages or envelopes several waveforms on a point by point basis
162. data Figure 3 90 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 increase accuracy because they reduce leakage TDS 694C User Manual 3 170 Using Features for Advanced Applications TDS 694C User Manual 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 waveform 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
163. disk drive Saving and Recalling Setups The TDS 694C Oscilloscopes can store up to ten instrument setups in internal memory that you may later recall This section 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 TDS 694C User Manual 3 115 Saving Waveforms and Setups To Save a Setup To save the current setup of the oscilloscope 1 Press SAVE RECALL SETUP Save Current 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 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 61 Now the current setup is stored in that location Tek Run 50 0MS s Sample ize DPO Brightness 76 Save Current Setup To File To Setup factory 1 To Setup 2 factory To Setup3 factory 1 of 3 piesa hcg aaa pe Select File current Factory pplication Utilities 20 0mvaQ
164. e 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 template you create in a different destination from that just stored 3 147 Using Features for Advanced Applications To Select a Limit Test Source To Specify the Limit Test Response 3 148 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 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 23 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
165. e Move Box TDS 694C User Manual Measuring Waveforms Histogram Measurement List The TDS 694C Oscilloscope provides you with 10 histogram measurements Table 3 6 lists brief definitions of the measurements Table 3 6 Measurement definitions Name Mean Median StdDev Definition The average of all acquired points within or on the histogram box Half of all acquired points within or on the histogram box are less than and half are greater than this value The standard deviation R oot Mean Square RMS deviation of all acquired points within or on the histogram box Hits in Hits in Box Box Displays the number of points in the histogram box or on the box boundary Waveren Waveform Count Displays the number of waveforms that have contributed to the histogram oun Peak Hits Displays the number of points in the largest bin of the histogram Pk Pk Displays the peak to peak value of the histogram Vertical histograms display the voltage of Mean 1 StdDev Mean 2 StdDev Mean 3 StdDev Measurement Readouts Display Histogram Measurements TDS 694C User Manual the highest nonzero bin minus the voltage of the lowest nonzero bin Horizontal histograms isplay the time of the rightmost nonzero bin minus the time of the leftmost nonzero bin he percentage of points in the histogram which are within 1 standard deviation of the istogram mean Qa
166. e 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 TDS 694C User Manual Tutorial Press SETUP gt Recall Factory Setup main gt OK Confirm Factory Init side Press AUTOSET 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 Press CH 2 gt CLEAR MENU Press SAVE RECALL SETUP gt Save Current Setup main to display the Setup main menu See Figure 2 18 CAUTION Setup locations in the side menu appear with the label user if they A N 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 labeled factory have the factory setup stored as a default and can be used to store current setups without disturbing previously stored setups z Tek Run 100kKS 5 Sample ch 200mv 100mY M 500ys chi 248mV A Save Current Setup uJ To File To Setup1 user To Setup 2 factory To Setup3 factory more 1of3 zir a Thea SORR SIRE AER Saved Curre
167. e amount of time the oscilloscope waits depends on the time base setting 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 3 49 Triggering on Waveforms 3 50 To Set Slope ae NG To Set Level 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 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 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 gt Type main 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 Lev
168. e base the oscilloscope only displays one time base and time division setting for all the active channels 2659 Acquisitions Delay Tims16 50ns amp Tek Stopped Record View Readout Time Base Main Only Intensified gee Delayed Only Delayed Runs 16 50n5 p j 4 2 After Main tucks ont co edd agate oop ae oe Delayed nee ien chi if 200mv Triggerable see Delayed Trig Menu Time Base Readout Trigger osition 50 FastFrame Extd Acq Figure 3 5 Record View and Time Base Readouts TDS 694C User Manual Acquiring and Displaying Waveforms To Change Horizontal Scale and Position TDS 694C User Manual The TDS 694C Oscilloscopes provides control of horizontal position and scale using the horizontal front panel knobs By changing the horizontal position 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 To change the horizontal scale and position 1 Turn the horizontal POSITION and horizontal SCALE knobs See Figure 3 6 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 POSITIO
169. e cannot slew rate trigger on pulse edges that traverse between 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 To understand what happens when you slew rate trigger study Figure 3 41 as you consider the following points m 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 3 77 Triggering on Waveforms Cursors Measure Slew Rate Components of Pulse Edge dv and dt Trigger Bar at Upper Threshold Trigger Point at Second Crossing Trigger Bar at Lower Threshold 3 78 Tek Run S00MS 5 Average Delta Time 250 0ns iL Slew Rate Trigger When ai Trig if Faster Than Trig if Slower Than Delta Time z A Slew Rate ta a GLOSS 1 00 V oons Slew Ch1 EEEE E a ea _ hype Class acung polarity when amp lt Pulse gt lt Slew gt Faster Holdoff OIOI aao DHG Figure 3 41 Main Tr
170. e front and rear panels and the menu system of the TDS 694C Oscilloscopes 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 i Tektronix TDS 694C BETAL REALTIME oscutoscoPe 106S File System page 3 122 Side Menu Buttons page 2 7 Ey es es fe es Oe cutar menu CLEAR Removes Menus from the Display ON STBY Switch Main Menu Buttons page 1 7 page 2 7 TDS 694C User Manual Operating Interface Maps Front Panel Map Right Side Measurement System page 3 88 Cursor Measurements page 3 98 Saving and Recalling Waveforms page 3 118 File System page 3 122 Hardcopy page 3 127 File System page 3 122 Acquisition Modes page 3 17 F SAVEIRECALL AUTOSET WAVEFORM Autoset page 3 4 STATUS HELP SETUP Help page 3 143 Status page 3 141 Saving and Recalling Setups page 3 115 Selecting Channels page 3 6 Waveform Math page 3 150 APPLICATION MEASURE 7 MENU ACQUIRE MENU HARDCOPY RUN STOP SELECT _ UTILITY SHIFT DISPLAY DELAYED TRIG SINGLE TRIG FORCE TRIG Z PROBE COMPENSATION SIGNAL GND ADJUST PROBE AT im ira t0pF 50 a 400V pk lt 5V RMS CH 3 Ve
171. e 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 Logic pop up gt Class main Setup Hold pop up 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 Logic pop up gt Class main Setup Hold pop up gt Set Hold Times main Setup Time or Hold Time side See Figure 3 35 2 Turn the general purpose knob or use the keypad to set values for the setup and for the hold times NOTE See Setup Hold Time Violation Trigger Minimum Clock Pulse Widths specification in the Performance Verification and Specifications manual for valid setup and hold times 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 2 2 ns Attempting to set either time to reduce the 2 ns limit adjusts the other time to maintain the limit TDS 694C
172. e recall SETUP gt Recall Factory Setup main gt OK Confirm Factory Init side 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 5 to be sure the oscilloscope triggers on the input signal Tutorial 2 12 44 TRIGGER MAIN LEVEL f TRIG D j READY DELAYED TRIG aam TRIGGER MENU C D SET LEVEL TO 50 SET LEVEL TO 50 Button gt __ Examine the Display Elements Figure 2 5 Trigger Controls Read the following information to become familiar with the oscilloscope display before doing the examples Figure 2 6 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 m 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 TDS 694C User Manual Tutorial m The trigger readout shows that the oscilloscope is triggering on cha
173. e the date time displayed with the new settings 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 69 Oscilloscope GPIB RS 232 or Centronics Cable Figure 3 69 Connecting the Oscilloscope Directly to the Hardcopy Device 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 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 TDS 694C User Manual 3 132 Saving Waveforms and Setups TDS 694C User Manual 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
174. eck 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 Check that you have the proper electrical connections The oscilloscope requires 100 to 240 VACRrms continuous range 45 Hz to 440 Hz and may require up to 450 W TDS 694C User Manual Start Up Power Connector Principal Power Switch ogo Fuse Figure 1 1 Rear Panel Controls Used in Start Up 5 Connect the proper power cord from the rear panel power connector see Figure 1 1 to the power system Table 1 2 Fuse and fuse cap part numbers Fuse 0 25 inch x 1 25 inch UL 198 6 3AG 6 A FAST 250 V 5mm x 20 mm IEC 127 5 A T 250 V Fuse part number 159 0013 00 159 0210 00 Fuse cap part number 200 2264 00 200 2265 00 Front Cover Removal To remove the front cover grasp the left and right edges and snap the cover off of the front subpanel To reinstall the cover 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 switch is on see Figure 1 1 The principal power switch controls all AC power to the instrument 2 I
175. ect the oscilloscope will acquire a waveform record with the first valid trigger event and stop In Envelope or Average mode the oscilloscope will make the specified number of acquisitions to complete the averaging or enveloping task 3 21 Acquiring and Displaying Waveforms Preventing Aliasing 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 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 3 145 Under certain conditions a waveform may be aliased on screen Read 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
176. egative or Either side Positive monitors the slew rate of the positive going edges of pulses The edge must first cross the lower threshold and then cross the upper threshold TDS 694C User Manual 3 75 Triggering on Waveforms 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 Pulse pop up gt Class main 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 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
177. eiving 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 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 65 To Set Confirm Delete 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 TDS 694C User Manual 3 125 Saving Waveforms and Setups To Set Overwrite Lock To Select a Drive k To Format k Connecting Printers and Zip Drives 3 126 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 sele
178. ent 1 Searching from Start to End find the first sample in the measurement zone less than LowRef 2 From this sample continue the search to find the first positive crossing of Lowkef The time of this crossing is the low rise time or TLR Use linear interpolation if necessary B 13 Appendix B Algorithms RMS 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 RMS Start End Start x SampleInterval For details of the integration algorithm see below TDS 694C User Manual Appendix B Algorithms Integration Algorithm TDS 694C User Manual The integration algorithm used by the oscilloscope is as follows W t dt A 2 is approximated by f where W ndt 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 BT ay Be ae Wi WG 2D Wndt s Xx Der ae A i A where s
179. er Manual Using Features for Advanced Applications Tek Run Se Average Select Measurement ser ren ied S02kKV s Pk Pk 1 Amplitude Positive Overshoot Negative Overshoot 1 200mva q M10 0u C 32mv more 5 of 8 REE 100kv s 10 0us ia n noian ii k Remove Gating Statistics Level Setu Measure EEC j Snapshot lt Measure gt MGlMiten Measrmnt OFF OFF Histogram LOIDID ICO la II 10 1 1 1a a Figure 3 92 Peak Peak Amplitude Measurement of a Derivative Waveform Offset Position and Scale 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 position 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 TDS 694C User Manual 3 175 Using Features for Advanced Applications Because of the method the oscilloscope uses to scale the source waveform before d
180. er 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 m 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 formats 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 TDS 694C User Manual 3 137 Saving Waveforms and Setups 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
181. er 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 want information on and press HELP again to re enter help mode TDS 694C User Manual SS ee ee ees Using Features for Advanced Applications The TDS 694C Oscilloscopes provides powerful features for testing and digitally processing the waveforms you acquire This section describes how to use the fol lowing features m 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 3 150 m Fast Fourier Transforms for displaying the frequency content of waveforms see page 3 153 m Waveform Differentiation for displaying the derivative of a waveform see page 3 172 m Waveform Integration for displaying the integral of a waveform see page 3 177 Limit Testing The TDS 694C Oscilloscopes provides limit testing which can automatically compare each incoming or math waveform against a
182. ers the definition must be met at the time the clock input changes state 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 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 and Hold Class 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 31 shows how the setup and hold times you choose positions this zone relative to the clock TDS 694C User Manual 3 52 Triggering on Waveforms To Check Logic Trigger Status TDS 694C User Manual 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 ends 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 loc
183. et 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 5 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 You can set an external attenuation or gain in addition to the attenuation specified by the probe To set external attenuation press VERTICAL MENU gt Probe Func tions main gt External Attenuation or External Attenuation in dB side External Attenuation Use the general purpose knob or the keypad to set the external attenuation as a multiplier Acquiring and Displaying Waveforms External Attenuation in dB Use the general purpose knob or the keypad to set the external attenuation in dB To Check the Check the Record View to determine the size and location of the waveform Horizontal Status record and the location of the trigger relative to the display See Figure 3 5 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 5 Also see Figure 3 3 on page 3 9 Since all live waveforms use the same tim
184. et in the source waveform may be enough to ensure that the integral waveform saturates clips especially with long record lengths TDS 694C User Manual 3 181 Using Features for Advanced Applications 3 182 Using Zoom 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 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 If you want 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 main gt Reset Live Factors or Reset All Factors side to return the zoomed integral waveform to no magnification TDS 694C User Manual a a Appendix A Options and Accessories Options This appendix describes the various options as well as the standard and optional accessories that are available for the TDS 694C Oscilloscope Tektronix will ship the options shown in Table A 1
185. f 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 volts 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 te 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 TDS 694C User Manual Glossary 2 Glossary TDS 694C User Manual Channel probe deskew A relative time delay for each channel This lets you align signals to compensate for the fact that signals may come in from cables of differing length Channel Reference Indicator The indicator on the left side of the display tha
186. f 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 TDS 694C User Manual Start Up 1 8 ON STBY Button Self Test Power Off Tektronix TDS 694C Seth ren Tue escuoscore ES Tek Run 100kS s5 Sample Tektronix 7 TDS 694C Digitizing Oscilloscope F v 1 0e Options 13 1F 2F c Copyright Tektronix Inc 1991 1999 All rights reserved Power On self check PASSED Push CLEAR MENU to proceed M 500s Chi F OV 18Jan 1999 09 29 30 Figure 1 2 ON STBY Button 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 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
187. fig ure main gt Hardcopy Talk Only side See Figure 3 66 TDS 694C User Manual Saving Waveforms and Setups Tek Run 2 50MS s Sample RS232 Baud Rate 9600 RS 232 HW Setup Baud Rate 9600 Stop Bits t Parity None Hard Flagging s ON am em 4a 1 00mV M40 0Ms Chi 78mV CR 1 GPIB 4 50 0mV_ A Oooo o Configure Software Hardcopy Setup laS lt Figure 3 66 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 DeskjetC Laserjet Epson DPU 411 DPU 412 PCX PCX Color TIFF BMP Mono BMP Color RLE Color EPS Mono Img EPS Color Img EPS Mono Pit EPS Color Pit Interleaf or HPGL side Press more side to page through all of these format choices NOTE Some formats such as DeskJetC require up to several minutes to process and print the screen When using these formats be careful not to inadvertently abort the print by pressing the Hardcopy button for a second print before the oscilloscope has finished processing and transmitting the first one TDS 694C User Manual 3 129 Saving Waveforms and Setups 3 130 3 Press SHIFT gt HARDCOPY MENU gt
188. for the specified channel or math waveform NOTE Specify the same reference memory you chose as the template destination if you want to use the template you just created If you have created more than 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 TDS 694C User Manual Using Features for Advanced Applications 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 3 127 for details m f you want the bell to ring when waveform data exceeds the limits set toggle Ring Bell if Condition Met side to ON m If you want the oscilloscope to stop when waveform data exceeds the limits set toggle Stop After Limit Test Condition Met side to ON 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
189. g the TLA Logic Analyzer s trigger state machine events of interest can be captured on the TDS694C and included in the statistical analysis Connect a TDS 694C Oscilloscope to a TLA 700 Series Logic Analyzer There is 300 to 500 ns of delay from the trigger state machine recognizing an event until the output pulse is generated To ensure accurate timing measurements characterize any delays including delays in the cable connecting the two instruments The first step in the cross trigger process should be aligning the two instruments Connect cables from the System Trig Out signal of the TLA Logic Analyzer to the Aux Trigger Input on the TDS 694C as follows TLA 714 Connect one end of a coaxial cable to the System Trig Out BNC connector on the TLA 714 rear panel Connect the other end of the BNC cable connector to Aux Trigger Input located on the rear panel of the TDS 694C See Figure 3 36 on page 3 64 3 63 Triggering on Waveforms Trig Out Signal 3 64 m TLA 720 Connect a P6041 probe to the System Trig Out SMB connector the TLA 720 front panel Connect the P6041 probe BNC cable end to a BNC to BNC connector Connect a coaxial cable to the BNC connector then connect the remaining BNC cable connector to the Aux Trigger Input located on the rear panel of the TDS 694C See Figure 3 37 TLA 714 Logic Analyzer Trig Out Signal ye TDS 694C Oscilloscope Aux Trigger Input with a 50Q terminator Coaxial cable
190. gic Function is TRUE CA 2168 Hig when Goes TRUE Goes FALSE Logic Function AND Becomes TRUE ae TRUE for less than ie eo ore ie ae ens Logic Function Becomes FALSE and an ao Od A ogier ane Er es sa Pay more than Triggers Acquisition i ee chi s0omva ich 5s00mva M 1004s e ig EE STOE mi ey a i ET _ Type Class Logic when amp stogic gt lt Pattern gt Inputs AND True gt Thresholds Holdoff II 11 101 1 1 Oooo Time Logic Function Must be TRUE Figure 3 34 Logic Trigger Menu Time Qualified TRUE TDS 694C User Manual 3 58 Triggering on Waveforms 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 51 through 3 52 describe how state triggers work To use state triggering do the following procedures Select State Triggering Press TRIGGER MENU gt Type main Logic pop up gt Class main 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 State pop up gt Define Inputs main 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
191. gure 2 13 The Menus After Changing Channels 2 20 Figure 2 14 Measure Main Menu and Select Measurement Side Menu en gee 2 22 Figure 2 15 Four Simultaneous Measurement Readouts 2 23 Figure 2 16 General Purpose Knob Indicators 2 24 Figure 2 17 Snapshot of Channel 1 02 e cece eee eee 2 26 Figure 2 18 Save Recall Setup Menu ceccecscceces 2 27 Figure 3 1 The Channel Readout cece cc ecscceces 3 8 Figure 3 2 Waveform Selection Priority eeeeeeee 3 9 Figure 3 3 Scaling and Positioning ccceccecscceces 3 11 Figure 3 4 Vertical Readouts and Channel Menu 3 12 Figure 3 5 Record View and Time Base Readouts 3 14 Figure 3 6 Horizontal Controls ccc cece cece ce cceees 3 15 Figure 3 7 Acquisition Input Analog Signal Sample and Digitize 0 ccc ccc cece ccc cece ee ee eee 3 18 Figure 3 8 Several Points May be Acquired for Bach Point Used o aerei eoin veto n aes enero si aie 6 3 18 Figure 3 9 Real Time Sampling 0ccceccccscscceces 3 19 Table of Contents Figure 3 10 How the Acquisition Modes Work 3 21 Figure 3 11 Acquisition Menu and Readout 665 3 22 Figure 3 12 Acquire Menu Stop After eee eee 3 23 Figure 3 13 Aliasing 0 ccc cece cece cece cece ee eeeens 3 24 Figure 3 14 Display Menu Style
192. h step 13 otherwise continue with step 18 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 TDS 694C User Manual 3 111 Measuring Waveforms 3 112 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 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 59 19 If desired repeat this procedure beginning at step to compensate for other probe channel combinations But before you do so be sure you take note of the following requirements m Remember to connect all probes to the oscilloscope for a twenty
193. han 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 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 62 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 i Tek Run 1 00MS s Sample E E Save waveform To File To Refl active To Ref2 active To Ref3 empty To Ref4 200mV F M50 0us Chi 200mv empty GEASS ete aave File Single Seq Format iliti s OFF Utilities Recall Wim e De to Ref 7 internal l ef SsSGSSSS Figure 3 62 Save Waveform Menu TDS 694C User Manual 3 119 Saving Waveforms and Setups 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 ope
194. he waveform record is not a DSP Math waveform FFT Time Domain Record that part of the waveform 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 86 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 FFT Time Domain Record 10k Waveform Record gt 10 K Zero Phase Reference Figure 3 86 Waveform Record vs FFT Time Domain Record 3 161 Using Features for Advanced Applications 3 162 FFTs Transform Time Records to Frequency Records The FFT time domain record just described is input fo
195. he 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 Nyquist Frequency Point Amplitude RSE Frequency Aliased Frequencies Actual Frequencies Se Figure 3 88 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 86 on page 3 161 TDS 694C User Manual Using Features for Advanced Applications 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
196. herwise manage the disk storage see Managing the File System on page 3 122 3 Press SHIFT gt HARDCOPY MENU gt Port main gt File side to specify that any hardcopy be output to a disk file 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 Saving files to the 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 Or you might load stored hardcopies from disk into your desktop publishing software that runs on a PC compatible computer TDS 694C User Manual Saving Waveforms and Setups To Print Using a Controller TDS 694C User Manual 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 Cen
197. 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 Acquisition Acquisition Interval Interval Trigger Level Indicates Trigger P oints Trigger Coupling JUL ULL PY ii a yY Holdoff Holdoff Holdoff Triggers are not recognized during holdoff time Figure 3 24 Trigger Holdoff Time Ensures Valid Triggering 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 Rejection High Frequency Rejection and Noise Rejection See To Specify Coupling on page 3 49 for a description of each coupling mode TDS 694C User Manual Triggering on Waveforms Trigger Position Slope and Level Se a Delayed Trigger System TDS 694C User Manual 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 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
198. ial 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 a diskette that is included with the user manual describes using a computer to control the oscilloscope through the GPIB interface m The TDS 500D TDS 600C amp TDS 700D Digitizing Oscilloscopes Reference Quick Reference gives you a quick overview of how to operate the oscilloscope m The TDS 500D TDS 600C amp TDS 700D Technical Reference Performance Verification and Specifications tells how to verify the performance of the oscilloscope and lists its specifications m The TDS 500B TDS 600B TDS 600B amp TDS 700A Service Manual provides information for maintaining and servicing the oscilloscope to the module level 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 xi Preface xii m Names also appear in the same case initial capit
199. ice 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 2 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 2 GHz AC DC current probes include Hall effect semiconductor devices and provide frequency response from DC to 100 MHz TDS 694C User Manual Appendix D Probe Selection Optical Probes TDS 694C User Manual 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 noninvasive 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 D 2 A6303 Current Probe Used in the AM 503S Opt
200. id2Ref 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 The oscilloscope 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
201. ide m If you select Off you turn off histogram displays Histogram counting and measurements can continue The histogram box is not turned off m If you select Log you display the log of the count in each bin Log scaling provides better visual detail for bins with low count m If you select Linear you display the count in each bin To select which waveform is compared against the histogram box press MEASURE gt Histogram pop up gt Histogram Options main gt Histogram Source side gt Ch1 Ch2 Ch3 or Ch4 side Histogram Source is not available in DPO because all on channels contribute to the histogram To set the size of the histogram display press MEASURE gt Histogram pop up gt Histogram Options main gt Histogram Size side Use the general purpose knob or keypad to set the histogram size The histogram box selects the section of the trace used for histograms To set the size of the histogram box press MEASURE gt Histogram pop up gt Histogram Box Limits main gt Top Limit Bottom Limit Left Limit or Right Limit side Use the general purpose knob or keypad to adjust the selected edge of the histogram box To move the histogram box without changing its size press MEASURE gt Measure main gt Histogram pop up gt Histogram Box Limits main Then toggle Move Box side to Horizontal or Vertical and use the general purpose knob to move the histogram box The SELECT button will also toggl
202. ie i a ee Snapshot on M Period 1 010ms Freq 990 16 Hz Width 480yus Width 530us Brstwd 4 050ms Rise 8S Fall Sus Duty 47 6 Duty 52 4 Over 1 6 Over 1 6 High 528mYV Low 24m Max 536mV Min 16mV Ampl 504m Pk Pk 520m Mean 262 4mvV CycMean 261 2mvV RMS 363 6mv CycRMS 362 8mvV nv K Area 1 30880mYs CycArea 263 84uYS i ren sec z FER me Remove Gating Statistics fax Setu Measure Measrmnt f Snapshot lt Measure gt for Ch Measrmnt OFF OFF E a Oooo lea ol Snapshot Display Oloo o Figure 3 52 Snapshot Menu and Readout TDS 694C User Manual 3 97 Measuring Waveforms To Find More Information Consider the following rules when taking a snapshot m 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 m To vary the source for taking a snapshot simply select another channel math or ref memory waveform and then execute snapshot again m 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 m Becareful when taking automatic measurements on noisy signals You might measure the frequency of the noise and not the desired waveform
203. ient 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 Glossary 9 Glossary Tee Glossary 10 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 detected 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 t
204. ifferentiating 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 Using 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 clipped portion Also the automated measurement Pk Pk will display a clipping error message if turned on see To Take Automated Measurements on page 3 174 If your derivative waveform is clipped try either of the following methods to eliminate clipping Reduce the size of the source waveform on screen Select the source channel and use the vertical SCALE knob 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 91 on page 3 174 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 Using Zoom Once you have you
205. igger Menu Slew Rate Class m The Trigger When side menu displays the readout Slew Rate that indicates the slew rate setting 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 Blew RATE Sue Delta Time Setting Substituting the threshold and delta time settings for the setup in Fig ure 3 41 Slew Rate Setting 45 L oS V 160 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 dv _ 4 Volts dt 200 ns Slew Rate Measured 20 mV ns TDS 694C User Manual Triggering on Waveforms m 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 m 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 up
206. ill get an error message at this step Setting the oscilloscope Utility menu is described under Set Communication Parameters on page 3 128 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 Exit the IBIC program by typing EXIT 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 your 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 TDS 694C User Manual Saving Waveforms and Setups Communicating with Remote Instruments The TDS 694C Oscilloscopes 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 To Prepare for Remote To transf
207. illoscope 0 00 00 0c 3 5 Waveforms Setting up Automatically Autoset and Reset 00 cece eee 3 6 Selecting Channels cit essen nera Wien eo ee LE ee E 3 8 Scaling and Positioning Waveforms 0 0 cece eee ee eee 3 10 Choosing an Acquisition Mode 00 eureun 3 17 Customizing the Display 0 0 0 eee eee eee eee 3 25 Customizing the Display Color 0 0 3 30 Zooming on Waveforms 0 0 0 eee eee e eee 3 35 Triggering on Waveforms Triggering Concepts 0 0 00 c ccc ence eee ene n rnrn 3 43 Triggering from the Front Panel 00 0 0 eee eee eee eee 3 48 Triggering on a Waveform Edge 0 0 eee 3 51 Triggering Based on Logic 0 cen e eee eee 3 55 Triggering On Pulses eresie in OS ee AR OR E E 3 67 Delayed Triggering ss eee Geis OG ee en Re E TE E 3 80 Measuring Waveforms Taking Automated Measurements 0 00 c eee eee eens 3 88 Taking Cursor Measurements 0 0 0 e eee cece eee eee 3 98 Taking Graticule Measurements 00 0 0 cece eee eee eee 3 103 Displaying Histograms 0 0 0 eee eee eee ene 3 104 Optimizing Measurement Accuracy SPC and Probe Cal 3 108 Saving Waveforms and Saving and Recalling Setups 0 0 cee ee eee eee 3 115 Setups Saving and Recalling Waveforms and Acquisitions 00 3 118 Managing the File System
208. ily calculate your peak to peak voltage as 3 103 Measuring Waveforms Measure Waveform Time Displaying Histograms 3 104 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 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 horizontal 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 The TDS 694C Oscilloscopes can display histograms constructed from the selected trace waveform data You can display either a vertical or horizontal histogram You can display only one type of histogram at a time See Fig ure 3 57 TDS 694C User Manual Measuring Waveforms Tek Run 100kS s Sample ove a eee RE Histogram Options Histogram Source Ch Histogram Vertical histogram gt vertical Histogram Display Wy 3 E I Linear Histogram ize 7 00 divs
209. ime 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 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 TDS 694C User Manual Glossary TDS 694C User Manual Side menu Menu that appears to the right of 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
210. imum 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 Negative overshoot measurement Amplitude voltage measurement Low Min x 100 NegativeOvershoot Amplinide 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 Glossary 7 Glossary Glossary 8 a gt OR A logi
211. in units of time or frequen cy To choose vertical bar cursor units do the following step Press CURSOR Time Units main gt seconds or 1 seconds Hz To find instructions for using cursors with math waveforms see Waveform Math on page 3 150 To find instructions on using cursor with FFT waveforms differentiated waveforms and integrated waveforms see Fast Fourier Transforms on page 3 153 Waveform Differentiation on page 3 172 and Waveform Integration on page 3 177 Taking Graticule Measurements Measure Waveform Amplitude TDS 694C User Manual The TDS 694C Oscilloscopes 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 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 eas
212. ing Features for Advanced Applications F D Tek Run 5 00MS s Sample 4s Cursor 3yVs Function Integral Math Waveform ae fer aa Pe Ry een A Source Waveform 5 a M 10 045 Chis 520m v Es Figure 3 94 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 TDS 694C User Manual 3 180 Using Features for Advanced Applications 13 Read the following 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 fro
213. ing equation Fn Kins XE 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 Create a Derivative ofa To obtain a derivative math waveform 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 91 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 press 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 694C User Manual 3 173 Using Features for Advanced Applications Derivative Math Waveform
214. ing message if the checksum calculation is successful displays a confirmation message You can select and load an application into the APPLICATION menu Then you can control the application using the APPLICATION menus To select an application do the following steps 1 Press SAVE RECALL SETUP gt Select Application main 2 Then use the general purpose knob to select the exact file from the resulting scrollbar list Only files with APP extensions are displayed Finally press Activate Application side to complete the operation To run file utilities see the Managing the File System on page 3 122 See Example 4 Saving Setups on page 2 26 Saving and Recalling Waveforms and Acquisitions 3 118 TDS 694C Oscilloscopes provides four internal reference memories in any of which you can store a waveform Waveforms thus stored are retained even when you turn the oscilloscope off or unplug it The oscilloscope also can save waveforms to disk This section describes how to save delete and display reference waveforms and acquisitions TDS 694C User Manual Saving Waveforms and Setups 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 t
215. 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 2 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 3 Wrap the oscilloscope with polyethylene sheeting or equivalent material to protect the finish 4 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 5 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 694C User Manual Appendix C Packaging for Shipment TDS 694C User Manual C 2 ee a er Appendix D Probe Selection The TDS 694C Oscilloscopes 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 and optical See Appendix A Options and Accessories for a list of the optional p
216. int This is a beneficial application for digital designers using the TLA 700 Series Logic Analyzer to troubleshoot possible setup and hold time violations on a synchronous bus If the setup and hold times are very small the Logic Analyzer resolution may not be enough to positively identify the marginal timing The TDS 694C oscilloscope can be used to observe 2 3 data lines along the with the clock signal this will provide a more precise measurement of the setup and hold times DRAM interface applications could require more than a 4 channel oscillo scope When a timing relationship of signals such as RAS CAS CS clock and data must be verified The TLA Series Logic Analyzer offers a solution to measure these signals with a 500 ps resolution If a problem is suspected on any four of the signals the TDS 694C can be used to zero in on the problem and provide even more timing resolution less than 15 ps The TLA Logic Analyzer s acquisition system is basically two dimensional voltage vs time A third statistical dimension is often needed for timing and characterization measurements The TDS 694C allows the users to statistically characterize an edge pulse width or clock period using histograms and measurement statistics Timing errors due to clock jitter can be measured and statistically characterized using the TDS 694C statistical measurements Not all events that trigger the oscilloscope should be included in the timing analysis so utilizin
217. ions 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 RN PositiveOvershoot TDS 694C User Manual Glossary TDS 694C User Manual 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 acquired 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 fill a waveform record from a single trigger event Use real time sampling to capture single shot or trans
218. ionships When you choose the XY format any channel or reference displayed is assigned to the axis indicated in Table 3 2 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 2 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 3 27 Acquiring and Displaying Waveforms Customizing the Display Color Change the Display Color 3 28 The TDS 694C Oscilloscopes can display information in different colors This section describes how to u
219. is the sample interval Similarly wo dt A B is approximated by f 2 where WO 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 B 1 Rees vm ar sx SSO WO x Mit Dt WES DY A where s is the sample interval B 15 Appendix B Algorithms 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 MidR ef Both min and max samples are above 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 694C User Manual B 16 Appendix B Algorithms 2 If the pair gt MidRef use the minima else use maxima If all pairs straddle MidRef use maxima See Figure B 4 The Burst Width measurement always uses both maxima and minima to determine crossings Missing or Out of Range Samples TDS 694C User Manual If some sa
220. it between the actual values acquired It assumes all the interpolated points fall in their appropriate point in time on that curve Intensity Display brightness 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 time 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 TDS 694C User Manual Glossary 7 TDS 694C User Manual 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 Max
221. itch Main Trigger menu 3 73 Remote communication 3 139 3 142 Remote operation Communicating with Remote Instruments 3 139 Connecting to the GPIB 3 141 GPIB interface requirements 3 139 GPIB Protocols 3 139 Interconnect cabling 3 140 Preparation for 3 139 Procedures for 3 141 Selecting and configuring the port 3 141 Remove Measrmnt Measure menu 3 94 3 99 Rename File Utilities menu 3 126 Reset How to execute 3 8 Reset All Mappings To Factory Color menu 3 34 Reset All Palettes To Factory Color menu 3 34 Reset Current Palette To Factory Color menu 3 34 Reset to Factory Color Color menu 3 31 Reset Zoom Factors Zoom menu 3 37 Restore Colors Color menu 3 33 Ring Bell if Condition Met Acquire menu 3 151 Rise time 2 22 3 92 Glossary 10 Rising edge Delayed Trigger menu 3 87 Rising edge Main Trigger menu 3 52 3 61 3 62 RLE Color Hardcopy menu 3 131 RMS 3 92 Glossary 10 RS 232 2 5 RS 232 Port 3 132 3 139 RUN STOP Foot Switch 3 23 RUN STOP Acquire menu 3 23 Runt trigger 3 69 3 70 Glossary 10 How to set up 3 73 3 88 Runt Main Trigger menu 3 73 Index 11 Index S Sample acquisition mode 3 20 Glossary 10 Sample interval Glossary 10 Sample Acquire menu 3 22 Sampling 3 19 Glossary 10 Sampling and digitizing 3 18 Saturation Color menu 3 32 Save Setups 3 117 Save Current Setup Save Recall Setup menu 3 118 Save Format Save Rec
222. itional processing such as 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 8 Several Points May be Acquired for Each Point Used TDS 694C User Manual Acquiring and Displaying Waveforms Real time Sampling Interpolation The Acquisition Modes TDS 694C User Manual The general method of sampling are real time and equivalent time The TDS 694C Oscilloscopes use only real time sampling In real time sampling the oscilloscope digitizes all the points it acquires after one trigger event see Figure 3 9 Always use real time sampling to capture single shot or transient events Record Points Po ee Sampling Rate JUUUUUUUUUL Figure 3 9 Real Time Sampling Your oscilloscope can interpolate between the samples it acquires 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 Eventually the time period established by scale setting does not allow enough time to get all the real samples neede
223. itude points of a positive pulse Pa Rise time ag RMS Extinction Ratio Extinction Extinction dB Mean dBm Measurement Readouts 3 90 Timing measurement Time taken for the leading edge of the first pulse in the waveform or gated region to rise from a Low R ef value default 10 to a High Ref value default 90 of its final value Voltage measurement The true Root Mean Square voltage over the entire waveform or gated region The value High Low The value 100 E xtinction Ratio The value 10 log10 Extinction R atio Average optical power 10 log10 Mean 0 001 With no menus displayed the measurement readouts appear far right of the display graticule See Figure 3 47 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 TimeStamp uses the measurement readouts therefore turning on FastFrame TimeStamp turns off Measurements and vice versa Measurement 1 is the top readout Measurement 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 TDS 694C User Manual Measuring Waveforms Measurement Readout Area Tek Run 250kKS 5 Sample C1 Period 1 0036ms Min 996 045 T Max 1 004ms c1 width 4 503 65 Min 495 6pys S Max 504 448 cl Duty 4
224. ive Waveform cece cece cece cece eee eees 3 177 Figure 3 93 Integral Math Waveform ececeeececes 3 181 Figure 3 94 H Bars Cursors Measure an Integral Math Waveform oec ereere eiee thao bie 24g Bie EE ota eee eee 3 182 Figure B 1 MCross Calculations cececcscscceees B 4 Figure B 22 Fall Tie ee 165 dee baie ei sine day ois ede wo die oS piece dw ie Sls eb B 9 Figure B 3 Rise Time cece ccc cece cece eee e ee eeeees B 14 Figure B 4 Choosing Minima or Maxima to Use for Envelope Measurement syrcas e055 enaa a eesti wide rene oie duels Sa B 16 Figure D 1 Typical High Voltage Probes 0e ee eeeee D 3 Figure D 2 A6303 Current Probe Used in the AM 503S Opt 03 ss 055 cd seo esis soe eeun suet es eeu tieee es D 5 Figure F 1 Equipment Needed to Run the Example Programs F 1 TDS 694C User Manual Table of Contents List of Tables TDS 694C User Manual Table 1 1 Table 1 2 Table 3 1 Table 3 2 Table 3 3 Table 3 4 Table A 1 Table A 2 Table A 3 Table A 4 Table A 5 Table E 1 Key Features of TDS 694C Fuse and fuse cap part numbers Autoset defaults c eee ewes XY Format pairs cece eeeeee Pattern and State Logic Pulse trigger definitions Table 3 5 Table 3 6 Table 3 7 Measurement definitions Measurement definitions Probe ca
225. knob 2 14 System 2 14 Horizontal menu 3 84 Delayed Only 3 84 Delayed Runs After Main 3 17 3 84 Delayed Scale 3 16 Delayed Triggerable 3 17 3 86 Fit to screen 3 16 Horiz Pos 3 17 Horiz Scale 3 16 Intensified 3 84 3 86 Main Scale 3 16 Record Length 3 16 Set to 10 3 17 Set to 50 3 17 Set to 90 3 17 Time Base 3 84 Trigger Position 3 16 HORIZONTAL MENU button 3 45 3 84 Horizontal POSITION knob 3 15 3 36 Horizontal Readouts 3 14 Horizontal SCALE knob 3 15 3 36 HPGL 3 129 HPGL Hardcopy menu 3 131 Hue Color menu 3 31 I O Status menu 3 143 TDS 694C User Manual Index TO Utility menu 3 23 3 130 Icons File Utilities menu 3 119 3 122 3 126 3 128 Independent Cursor menu 3 104 Infinite Persistence Display menu 3 26 Installation 1 6 Integral math waveform 3 179 applications 3 179 automated measurements of 3 183 derivation of 3 179 magnifying 3 178 3 184 procedure for displaying 3 180 procedure for measuring 3 181 record length of 3 179 Integration Waveform 3 179 Intensified Samples Display menu 3 25 Intensified Horizontal menu 3 84 3 86 Intensity Glossary 6 Intensity Display menu 3 26 Interleaf 3 129 Interleaf Hardcopy menu 3 131 Interpolation 3 19 3 28 Glossary 6 And zoom 3 35 FFT distortion 3 167 linear versus sin x x 3 167 K Keypad 2 7 2 24 Knob Glossary 6 General purpose 2 7 2 23
226. l Tek Run 100kS s Sample Chi zoom 1 0X Vert 2 0XHorz 0 00 Horizontal i Lock All Live None 2oomv SM 250s Chit 264mv itty Aa a ee ee ig Mode None Graticule Reset i Upper ceeiseeS Figure 3 20 Zoom Mode with Horizontal Lock Set to None 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 Press ZOOM gt Reset main gt Reset Live Factors or Reset All Factors side Reset Live Factors resets only for live waveforms as opposed to reference waveforms Reset All Factors resets for all waveforms The oscilloscope can display and control a waveform that is both zoomed and unzoomed magnified and unmagnified To do so it 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 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 21 2 To scale or position the unmagnified waveform press Selected Grati cule main gt Lower side Use the
227. l Time ch DC f 304mV MIP ICIC Figure 3 45 Delayed Trigger Menu 8 Press Source main 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 remains 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 49 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 indicates the level set by the delayed trigger system 3 85 Triggering on Waveforms 11 Press Level main 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 trigge
228. l status ccc cece ee eee OPtHONS ss nesse sre sence cos arsan wiser sree es Standard accessories ee e00 Optional accessories eeee00 Recommended probe cross reference Accessory Software ceceeceeees External inspection check list vii Table of Contents TDS 694C User Manual viii a ae a General Safety Summary To Avoid Fire or Personal Injury TDS 694C User Manual Review the following safety precautions to avoid injury and prevent damage to this product or any products connected to it To avoid potential hazards use this product only as specified Only qualified personnel should perform service procedures Use Proper Power Cord Use only the power cord specified for this product and certified for the country of use Use Proper Voltage Setting Before applying power ensure that the line selector is in the proper position for the power source being used Connect and Disconnect Properly Do not connect or disconnect probes or test leads while they are connected to a voltage source Ground the Product 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 Observe All Terminal Ratings To avoid fire or shock hazard observe all ratings and ma
229. ld cause personal injury or lead to further damage to the oscilloscope Table E 1 External inspection check list Item Inspect for Repair action Cabinet front panel Cracks scratches deformations Send in for service and cover damaged hardware or gaskets Front panel knobs Missing damaged or loose Send in for service knobs Carrying handle bail Correct operation Send in for service cabinet feet Cleaning Procedure Exterior To clean the oscilloscope exterior do the following steps 1 Remove loose dust on the outside of the oscilloscope with a lint free cloth 2 Remove remaining dirt with a lint free cloth dampened in a general purpose detergent and water solution Do not use abrasive cleaners 3 Clean the light filter protecting the monitor screen with a lint free cloth dampened with either isopropyl alcohol or preferably a gentle general purpose detergent and water solution CAUTION To prevent getting moisture inside the oscilloscope during external cleaning use only enough liquid to dampen the cloth or applicator Lubrication There is no periodic lubrication required for this oscilloscope TDS 694C User Manual B Appendix F Programmer Disk The TDS694C Programmer Manual disk is a Microsoft Windows help file that covers operating your oscilloscope using the General Purpose Interface Bus GPIB optional on some oscilloscopes The disk also includes some example programs The prog
230. ling main 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 HF Rej removes the high frequency portion of the triggering signal That allows only the low frequency components to pass on to the triggering system to start an acquisition High frequency rejection attenuates signals above 30 kHz 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 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 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 41 for a description of these features To set mode and holdoff do the following steps 1 Press the TRIGGER MENU gt Mode amp Holdoff main gt Auto or Normal side The modes operate as follows m In Auto mode the oscilloscope acquires a waveform after a specific time has elapsed even if a trigger does not occur Th
231. m the readout m Read the time difference between the long vertical bars of the paired cursors from the A readout To Take Automated You can also use automated measurements to measure integral math waveforms Measurements Use the same procedure as is found under To Take Automated Measurements on page 3 174 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 Offset Position and Scale 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 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 integral waveform DC Offset 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 offs
232. m 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 measuring noisy signals because it allows the oscilloscope to ignore minor fluctuations in the signal TDS 694C User Manual Appendix B Algorithms 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 MCross3 MCross2 EndCycle MCrossl StartCycle MidR ef Hysteresis x Amplitude MidR ef MidR ef Hysteresis x Amplitude Figure B 1 MCross Calculations 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 MCros
233. may come in from cables of different length 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 694C Oscilloscopes 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 You should run an SPC if the temperature has changed more than 5 C since the last SPC was performed 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 4 Wait for signal path compensation to complete up to 8 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
234. 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 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 m 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 data was stored If it is the oscilloscope sets status to pass if not it sets the status to Initialized TDS 694C User Manual Measuring Waveforms TDS 694C User Manual 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 TE
235. mples 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 B 17 Appendix B Algorithms TDS 694C User Manual B 18 EEE SS a Appendix C Packaging for Shipment If you ship the TDS 694C Oscilloscopes 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
236. n Waveforms Pattern and State Classes Pattern and state triggers apply boolean logic functions to the logic inputs Table 3 3 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 3 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 57 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 3 are met Table 3 3 Pattern and State Logic AND Clocked AND If allthe preconditions selected for the z logic inputs3 are TRUE then the oscilloscope triggers NAND L Clocked NAND If not all of the preconditions selected E for the logic inputs are TRUE then the oscilloscope triggers OR Clocked OR If any of the preconditions selected for E the logic inputs3 are TRUE then the oscilloscope triggers NOR Clocked NOR If none of the preconditions selected for E the logic inputs3 are TRUE then the oscilloscope triggers D 7 1 Note that for state class trigg
237. n 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 TDS 694C User Manual Acquiring and Displaying Waveforms 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 also can adjust the waveform position using the offset option in the Vertical menu discussed later in this section r Tek Run sarees Sample Ch Coupling Impedance DC AC LOJO C C O Vertical Readout Zoomy M So0ys chi 24amv Em Bandwidth Fine Scale position Deskew Probe Full 200RV _somdiv as Functions Figure 3 4 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 positi
238. nce is just before oscilloscope adjustment The cabinet helps keep dust out of the oscilloscope and must be in place when operating the oscilloscope The oscilloscope front cover protects the front panel and display from dust and damage Install it when storing or transporting the oscilloscope Inspect and clean the oscilloscope exterior as often as operating conditions require Send the oscilloscope in for service if it requires an interior cleaning The collection of dirt on components inside can cause them to overheat and breakdown Dirt acts as an insulating blanket preventing efficient heat dissipa tion Dirt also provides an electrical conduction path that could cause an oscilloscope failure especially under high humidity conditions CAUTION Avoid the use of chemical cleaning agents which might damage the plastics used in this oscilloscope Use only deionized water when cleaning the menu buttons or front panel buttons Use a 75 isopropyl alcohol solution as a cleaner and rinse with deionized water Before using any other type of cleaner consult your Tektronix Service Center or representative E 1 Appendix E Inspection and Cleaning Inspection Inspect the outside of the oscilloscope for damage wear and missing parts using Table E 1 as a guide Oscilloscopes that appear to have been dropped or otherwise abused should be checked thoroughly to verify correct operation and performance Immediately repair defects that cou
239. nd 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 edge trigger and certain classes of main pulse triggers This section describes how to delay the acquisition of waveforms 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 42 TDS 694C User Manual Triggering on Waveforms Delayed Triggerable After Time Delayed Triggerable After Events Delayed Triggerable After Events Time TDS 694C User Manual Wait for Main Trigger Wait User specified Time 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 43 to understand the sequence the oscilloscope goes through for each delayed mode Figure 3 42 Delayed Runs After Main p Wait for an Wait User specified Delayed Acquire i Time Trigger Data Trigger Event Wait the User specified Number of Delayed Trigger Events Wait the User specified Number of Delayed Trigger
240. nd time are removed from the display when menus are displayed Once the oscilloscope is connected to a hardcopy device press HARDCOPY to print your date time stamped hardcopy TDS 694C User Manual Saving Waveforms and Setups Tek Run 100kKS 5 Sample gil oom i sons Chi OW 25 Mar 1994 Date and Time Display 08 39 47 ne E SeS aG aG aG eS Figure 3 68 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 TDS 694C User Manual Press SHIFT UTILITY gt Config pop up gt Set Date amp Time main gt Year Day Month Hour or Minute side Use the general purpose knob 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 23 4 of June Repeat steps 1 and 2 to set other parameters as desired Press OK Enter Date Time side to put the new settings into effect This sets the seconds to zero 3 131 Saving Waveforms and Setups 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 se
241. ng and Blackman Harris TDS 694C User Manual 3 169 Using Features for Advanced Applications In step 8 page 3 157 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 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 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 Window Characteristics When evaluating a window for use you may want to examine how it modifies the FFT time domain
242. nnel 1 Ch1 on a rising edge and that the trigger level is about 200 300 mV m The time base readout shows that the main time base is set to a horizontal scale of 500 us div m The channel readout indicates that channel 1 Ch1 is displayed with DC coupling The oscilloscope always displays channel 1 at reset Tek Run 100kS 5 Sample Trigger Level Bar Trigger P osition Indicator Channel Reference Indicator Trigger Readout Time Base Readout Channel Readout 100 Recall Factory L NL M 500us Chi N 220mV Factory Init e ee H LES EE EE e Saved Current Factory Utilities Setup Setup Setu OK Confirm es aan C C C Co Figure 2 6 The Display After Factory Initialization OIOI 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 the readouts below the graticule Example 1 Displaying a Waveform The TDS 694C Oscilloscopes 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 694C Oscilloscopes TDS 694C User Manual 2 13 Tutorial Adju
243. nob 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 Select the record length desired from the side menu Press more to see additional choices TDS 694C Oscilloscopes have standard record lengths up to 30 000 points Record lengths up to 120 000 with Option 1M 2 To fit an acquired waveform or with Extended Acquisition On an acquisi tion 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 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 694C User Manual Acquiring and Displaying Waveforms 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 Se
244. nstance 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 P6249 have TEKPROBE interfaces TDS 694C User Manual 3 114 ae L R Saving Waveforms and Setups The TDS 694C Oscilloscopes 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 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 disk the disk can be a floppy disk the optional hard disk or an external Zip drive so you can recall and reuse those setups m Save Recall Waveform for saving waveforms to internal memory or to a 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 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 disk This section ends with details on how to connect your oscilloscope into a system environment so that it can communicate with remote instruments NOTE TDS Oscilloscopes do not come equipped with a hard
245. nt 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 tine 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 TDS 694C User Manual Measuring Waveforms Table 3 5 Measurement definitions cont Cycle RMS Definition Voltage measurement The true Root Mean Square voltage over the first cycle in the waveform or the first cycle in the gated region Delay Timing measurement The time between the MidR ef crossings of two different traces or the gated region of the traces Fall Time Timing measurement 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 Timing measurement for the first cycle in the waveform or gated region The reciprocal of the period Measured in Hertz Hz where 1 H
246. nt Factory Utilities Setup Setu Setup Figure 2 18 Save Recall Setup Menu TDS 694C User Manual C CoD C Oooo oj 2 27 Tutorial 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 exercise 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 694C User Manual 2 28 D Overview 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 fundament
247. nu TDS 694C User Manual 2 25 Tutorial Tek Run Beir Sample Snapshot Th o E Snapshot on S Period 1 oie Freq 990 16 Hz Width 480ps width 530ps Brstwd 2 4 050ms Rise Sus Fall 8ys Duty 147 6 Duty 52 4 Over 31 6 Over 21 6 High 528mY Low 24mvV Max 5336mV Min 16mY Ampl 504mV Pk Pk 520m Mean 262 4mY CycMean 261 2m RMS 363 6mv CycRMS 362 8mV nv g Area 2 1 30880m s CycArea 263 84yVs elec 7 Tat Messure measrmnt Remove Gating statisties Level setur MICO IG ClO S Figure 2 17 Snapshot of Channel 1 Example 4 Saving Setups 2 26 Save a Setup The TDS 694C Oscilloscopes can save its controls settings and recall them later to quickly re establish a setup It provides ten storage locations to store up to ten setups It also provides a file system so that you can also save setups to a floppy disk an optional hard disk or an external Zip drive 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 First you need to create an instrument setup you want to sav
248. od Voltage measurement Measured over the entire waveform or gated region NegativeDutyCycle x 100 Low Min x 100 NegativeOvershoot Amplitude 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 Voltage measurement The absolute difference between the maximum and minimum amplitude in the entire waveform or gated region TDS 694C User Manual 3 89 Measuring Waveforms Table 3 5 Measurement definitions cont Name GAO Phase Definition 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 as a percentage PositiveWidth x 100 PositiveDutyCycle Period Positive Overshoot Voltage measurement over the entire waveform or gated region Max High Ampitude 10 PositiveOvershoot Positive Width Timing measurement of the first pulse in the waveform or gated region The distance time between MidR ef default 50 ampl
249. off the oscilloscope toggle the ON STBY switch TDS 694C User Manual D Overview This chapter describes the basic concepts of operating the TDS 694C Digital Real Time 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 section see Reference A list of the topics covered begins on Page 3 1 TDS 694C User Manual 2 1 Overview TDS 694C User Manual POE Operating Interface Maps This section contains illustrations or maps of the display th
250. ommended probe cross reference Probe TDS 694C Specialty P 6339A 10X Low Capacitance P6158 Active lt 3 5V Logic P6249 Active gt 3 5V Logic P6245 Active CMOS TTL P6245 All Technology P6245 Differential Digital P6246 Telecom P6248 Micro Volt ADA400A High Voltage P5210 Current CT 1 AC Only CT 2 CT 6 Current TCP 202 AC DC AM503S Electro Optical Converter P6701B P6703B TDS 694C User Manual A 3 Appendix A Options and Accessories A 4 Accessory Probes NOTE The TDS 694C oscilloscope does not have a 1MQ input impedance therefore many passive high voltage and current probes will not work correctly Use probes with 509 output impedance only The following optional accessory probes are recommended for use with your TDS 694C m P6245 Active high speed digital voltage probe FET DC to 1 5 GHz m P6248 Active high bandwidth differential probe FET DC to 1 5 GHz m P6249 Active small geometry active probe 5X 3 GHz m P6339A 500 MHz buffered passive AC DC coupling 20 150 MHz bandwidth limit probe for TDS 794D m ADA 400A differential preamp switchable gain m AM 503S DC AC 50 MHz Current measurement system AC DC Supplied with A6302 Current Probe m AM 503S Option 03 DC AC 100 A Current measurement system AC DC Supplied with A6303 Current Probe m AM 503S Option 05 DC AC 100 MHz Current measurement system Supplied with A6312 Current Probe m TCP 202 Current Probe DC to 50 Mhz
251. on Tek Run 50 0MS s Sample R O E E E e LENS M i 00us Chi 1 34 V Math 10 0 dB 2 50MHz ES IEB 9191 Figure 3 85 Cursor Measurement of an FFT Waveform 6 Press V Bars side Use the general purpose knob to align one of the two vertical cursors to a point of interest along the horizontal axis of the waveform 7 Press SELECT to select the alternate cursor 8 Align the selected cursor to another point of interest on the math waveform TDS 694C User Manual 3 159 Using Features for Advanced Applications To Take Automated Measurements of an FFT The FFT Frequency Domain Record 3 160 9 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 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 Vrm
252. on 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 m The Boolean logic function select from clocked 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 A setup hold trigger occurs when a logic input changes state inside of the setup and hold times relative to the clock 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 3 51 Triggering o
253. on is particularly useful when you are comparing two or more waveforms TDS 694C User Manual Acquiring and Displaying Waveforms To Change Vertical Parameters DC GND To Set External Attenuation TDS 694C User Manual To select the coupling and offset for the selected waveform use the Vertical menu Figure 3 4 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 NOTE The TDS 694C requires a P6339 probe for AC coupling 10 MQ input impedance and bandwidth selections to appear in the menus 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 GND or side m DC coupling shows both the AC and DC components of an input signal m Ground GND coupling disconnects the input signal from the acquisition 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 Press Set to 0 divs side if you want to reset the reference point of the selected waveform to the center of the display Offs
254. onventional 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 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 you cannot retrieve them To use Tek Secure to remove all reference setups and waveforms does not affect mass storage disks Press SHIFT UTILITY System main gt Config pop up gt Tek Secure Erase Memory main gt OK Erase Setup amp Ref Memory side TDS 694C User Manual 3 117 Saving Waveforms and Setups Select an Application To Run the File Utilities To Find More Information 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 warn
255. or hold time of the clock Pages 3 51 and 3 52 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 Logic pop up gt Class main 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 Setup Hold pop up gt Data Source main 2 Press any one of Chl Ch2 Ch3 or Ch4 side Do not select the same channel for both the data and clock sources 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 MENU gt Type main gt Logic pop up gt Class main Setup Hold pop up gt Clock Source main Ch1 Ch2 Ch3 or Ch side 2 Press any one of Chl 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 TDS 694C User Manual 3 60 Triggering on Waveforms 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 Setup Hold pop up Levels main Clock Level or Data Level side 2 Turn the general purpose knob or use th
256. ossing 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 _ MCross1Ref MCross1Target y 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 TDS 694C User Manual Appendix B Algorithms Positive Duty Cycle Positive Overshoot Positive Width Rise Time e TDS 694C User Manual 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 E _ PositiveWidth PositiveDutyCycle baod 100 Amplitude voltage measurement Max High Amplitude ee 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 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 measurem
257. ource 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 desired channel or reference waveform Ke 5 Tek Run 100kKS 5 Sample Math Change Math waveform definition No Extended ee Processing Average 2 ch 1o0omy Ooo Math2 DIP ICIC IW C e Figure 3 80 More Menu 3 Press Set Function to side repeatedly to cycle it to inv invert intg or diff Waveform integration intg is described on page 3 177 and waveform differentiation diff is described on page 3 172 4 Tocreate the math waveform press OK Create Math Wfm side TDS 694C User Manual 3 151 Using Features for Advanced Applications 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
258. p for 3 130 Printing a hardcopy 3 129 Spool 3 135 Hardcopy Talk Only Utility menu 3 130 HARDCOPY button 3 125 3 131 3 141 Hardcopy if Condition Met Acquire menu 3 151 Hardcopy menu BMP Color 3 131 BMP Mono 3 131 Clear Spool 3 132 3 135 Deskjet 3 131 DeskjetC 3 131 DPU411 II 3 131 DPU412 3 131 EPS Color Img 3 131 EPS Color Plt 3 131 EPS Mono Img 3 131 EPS Mono Plt 3 131 Epson 3 131 Format 3 131 GPIB 3 132 HPGL 3 131 Interleaf 3 131 Landscape 3 132 Laserjet 3 131 Layout 3 132 OK Confirm Clear Spool 3 135 Palette 3 132 PCX 3 131 PCX Color 3 131 Port 3 132 Portrait 3 132 RLE Color 3 131 Thinkjet 3 131 TIFF 3 131 Hardcopy Color menu 3 31 Hardcopy Utility menu 3 141 Help Accessing 3 143 HELP button 3 145 Help system 3 143 HF Rej Main Trigger menu 3 51 High 3 91 Glossary 5 Index 6 High Ref Measure menu 3 97 High speed active probes D4 High voltage probes D 2 High Low Setup Measure menu 3 96 Histogram counting 3 107 measurements 3 109 menu 3 107 3 108 Histogram menu 3 107 Histogram Measure menu 3 96 Histograms 3 106 HistoMasks Status menu 3 143 Hits in Box 3 109 Holdoff trigger 3 44 Glossary 6 Horiz Pos Horizontal menu 3 17 Horiz Scale Horizontal menu 3 16 Horizontal Bar cursors 3 101 Glossary 6 Control 3 15 3 40 Menu 3 45 Position 3 15 Readouts 3 14 Scale 3 15 SCALE
259. pad 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 Processing side Any math operations you select for the waveform are performed on only one acquisition The Advanced DSP Math capabilities of the TDS 694C Oscilloscopes 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 TDS 694C User Manual 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 3 153 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 s7 _j2nnk 1 N X k 7 x n e for k 0 toN 1 jee 2 Where x n is a point in the time domain record data array
260. per 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 holdoff refer to Set Mode amp Holdoff on page 3 49 To learn more about trigger mode and holdoff see Trigger Modes and Trigger Holdoff on page 3 41 Trigger Based on When you select the pulse class Timeout the TDS oscilloscope will trigger on a Pulse Timeout pulse change that does NOT occur within the specified limits That is the trigger will occur when depending on the polarity you select the signal stays higher or stays lower than the trigger level for the timeout value To set up for timeout triggering do the following procedures Select Timeout Triggering Press TRIGGER MENU gt Type main Pulse pop up gt Class main Timeout pop up Select the Source Press TRIGGER MENU gt Type main gt Pulse pop up gt Source main 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 Pulse pop up gt Class main Timeout pop up gt Polarity main gt Stays High Stays Low or Either side 4 Stays High causes a trigger to occur if the signal stays higher than the trigger level for longer than the timeout value pe Stays Low causes a trigger to occur if the signal stays lower than the trigger level for longer th
261. play Style TDS 694C User Manual The TDS 694C Oscilloscopes can display waveform records and other display elements in different ways This section describes how to adjust the oscilloscope display style intensity level graticule and format 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 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 28 Press DISPLAY gt Settings main gt Display pop up gt Style main gt Vectors Dots Intensified Samples Infinite Persistence or Variable Persistence side See Figure 3 14 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 or Zoom must be on with its horizontal expansion greater that 1X See Interpolation on page 3 17 see Zooming on Waveforms on page 3 32 3 23 Acquiring and Displaying Waveforms 3 24 Adjust Intensity Set Display Re
262. ple Acquire Stop After RUN STOP button only Deskew Channel P robe Unchanged Display Style Vectors Display Intensity Overall If less than 50 set to 75 Display Format YT Horizontal Position Horizontal Scale Centered within the graticule window As determined by the signal frequency Horizontal Time Base Main Only Horizontal Record Length Unchanged Horizontal Lock Unchanged Horizontal Fit to Screen Unchanged Limit Test Off 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 Vertical Scale Default Holdoff S et equal to 5 horizontal divisions Adjustable Holdoff 250 ns Selection in Mode and Holdoff menu determines whether the default holdoff value or the adjustable hold value is used As determined by the signal level Vertical Coupling Vertical Offset Zoom DC 0 volts except offsetable probes the offset will be set to the mid point of the signal Off Acquiring and Displaying Waveforms To Reset the Oscilloscope Selecting Channels To Identify the Selected Channel Channel Reference pein Indicator 8 i 4 OK Channel Readout gt iia 0 0mva TE aaa es ei 3 6 Do the following steps to reset the oscilloscope to its factory default
263. r less 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 88 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 amplitude 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 TDS 694C User Manual 3 165 Using Features for Advanced Applications Considerations for Phase Displays 3 166 m Filter t
264. r level to 50 of the peak to peak value of the delayed trigger source signal NOTE Trigger level range is always 12 divisions from the center of the vertical range Some combinations of vertical scale offset and position result in a trigger range that prevents Set to TTL or Set to ECL from achieving their desired settings In this case the trigger level is set as close as possible to the desired setting TDS 694C User Manual 3 86 E eee Measuring Waveforms To make the best use of the TDS 694C Oscilloscopes when taking measure ments you need to know how to use the five types or classes of measurements it can take This section describes how to take the following classes of measure ments Figure 3 46 shows four measurement classes m Automated for automatically taking and displaying waveform measurements m Cursor for measuring the difference either in time or voltage between two locations in a waveform record m Graticule for making quick estimates by counting graticule divisions on screens m Histogram for displaying and automatically measuring how your vertical and horizontal units vary in the histogram box m Masks for mask counting selecting a mask or editing a mask This section also tells you how to use Probe Cal Channel Probe Deskew and Signal Path Compensation to optimize the accuracy of your measurements Histogram Cursor Automated Histogram box Graticule Readouts Measurements Chl Frequency
265. r the FFT Figure 3 87 shows the transformation 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 87 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 6
266. r 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 TDS 694C User Manual 3 176 Using Features for Advanced Applications Waveform Integration TDS 694C User Manual Whether zoom is on or off you can press Reset main gt Reset Live Factors or Reset All Factors side to return the zoomed derivative waveform to no magnification The Advanced DSP Math capabilities of the TDS 694C Oscilloscopes 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 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 The integral math waveform derived from the sampled waveform is computed based on the following equation
267. r you can set the glitch trigger to reject 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 A timeout trigger occurs when the trigger source does not detect a pulse edge when it expected to Figure 3 38 shows the pulse trigger readout Table 3 4 on page 3 68 describes the choices for pulse triggers 3 67 Triggering on Waveforms Glitch j width Slew Rate Timeout Class lt Runt gt Source chi M 50 0ns R n Chi Trigger Class Runt J Set to ECL orc Polarity Positive Occurs i ode hresholds amp Holdoff
268. ram runs on a PC compatible system with Microsoft Windows 95 See Figure F 1 PC Compatible with TDS694C Microsoft Windows 95 d Manual Figure F 1 Equipment Needed to Run the Example Programs Loading the Programs For instructions on installing the programmer manual and the other software on the TDS694C Programmer Manual disk read the readme file on the disk Running the Help Program To run the programmer manual help file using Windows 95 perform the following m Select Start Programs and then click the TDS694C Digital Real Time Programmer Manual m If you have not created a Windows 95 shortcut use the File Manager Explorer Windows 95 to select and run the TDS pgm hlp program TDS 694C User Manual Appendix F Programmer Disk TDS 694C User Manual F 2 IE Glossary 2 2 channel operation Two plus two channel operation limits the simultaneous display of channels to two of the four channels provided Channels not displayed can be used to couple a triggering signal to the oscilloscope 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
269. ration NOTE Upon power on the oscilloscope creates the wild card file marked in shown left for storing waveforms Selecting this file in step 3 stores a waveform in a uniquely named sequentially numbered file For instance the oscilloscope saves the first waveform you save in the file TEKO0001 WFM the second in TEK00002 WFM and so on Recalling an image histogram stops acquisitions To Change Format To select the format that the oscilloscope uses to save waveforms to a disk Press save recall WAVEFORM gt Save Format main gt Internal MathCad or Spreadsheet side Internal creates files WFM or WF1 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 If you are writing a MathCad program note that the TDS MathCad file is an ASCII file the first four values of which contain header information m The first header value holds the TDS record length m The second header value holds time in seconds between samples m The third header value holds the trigger position expressed as an index in the data position m The fourth header value refers to the fractional trigger position Also note that the delimiters are carriage returns To Delete Waveforms To delete a reference waveform s that you no longer need Press SAVE RECALL WAVEFORM
270. rection of FFTs 3 165 Vertical POSITION knob 3 11 3 35 Vertical Readout 3 10 Vertical SCALE knob 3 11 3 35 VGA Output 2 5 Video Line Number Cursor menu 3 105 View Palette Color menu 3 31 W Waveform Glossary 12 Acquiring and Displaying of 3 5 Autoset on 3 6 Coupling to the oscilloscope 3 5 Interval Glossary 12 Math 3 152 Priority for turning off 3 9 Saving 3 117 Triggering on 3 41 Waveform clipping See Clipping Waveform Count 3 109 Waveform differentiation 3 174 Waveform FFTs 3 155 Waveform integration 3 179 Waveform memory 3 122 WAVEFORM OFF button 2 20 3 9 3 29 Waveform record FFT 3 162 FFT frequency domain 3 163 length of 3 163 FFT source 3 162 acquisition mode 3 166 defined 3 163 long versus short 3 165 FFT time domain 3 163 Waveform Display menu 3 26 Waveforms And zoom 3 34 Math 3 155 Measuring 3 89 Scaling and positioning 3 10 Waveforms Status menu 3 143 Width 2 22 Glossary 7 Glossary 9 Width trigger 3 69 3 76 How to set up 3 76 3 88 Width Main Trigger menu 3 72 3 76 Window 3 170 Blackman Harris 3 159 3 171 3 174 characteristics of 3 172 Hamming 3 159 3 171 3 174 Hanning 3 159 3 171 3 174 rectangular 3 159 3 171 3 174 TDS 694C User Manual Index rectangular vs bell shaped 3 173 selecting 3 171 Windowing process 3 170 Windows descriptions of 3 159 X XY Format 3 29 XY format Glossary 12
271. red from previous acquisitions Peak Detect Mode 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 noninterpolated sampling If you set the time base so fast that it requires real time interpolation the mode automatically changes from Peak Detect to Sample although the menu selection will not change NOTE For record lengths of 30 000 points of less the Peak Detect sample interval will be 100ps For record lengths of 50 000 points or greater the Peak Detect sample interval will be 400ps TDS 694C 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 i s 3 E F Q ae 3 s Zhe Sample Q Uses first sample in inter
272. ree status lights TRIG D READY and ARM in the Trigger control area See Figure 3 26 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 oscilloscope 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 3 45 Triggering on Waveforms 3 46 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 27 The readouts differ for edge logic and pulse triggers Main Trigger Slope Rising Edge Main Trigger Source Ch 1 Main Time Base Time Div Main Trigger Main Time Base Level U 6 DIP IC IC C O O Figure 3 27 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 displ
273. reen information on any front panel button knob or menu item See Figure 3 77 TDS 694C User Manual 3 143 Determining Status and Accessing Help 3 144 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 display help 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 S FF 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 SHiF7 reverses the direction in which the pop up menu or button label toggles through the menu or parameter settings CIC C C O Gl ooma M 500us Chi OV 18Jan 1999 14 01 31 Kees oe oe es aoa Figure 3 77 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 Whenev
274. ring on Waveforms The Trigger Event Trigger Sources ACO 3 40 Triggered Waveform Untriggered Waveforms Figure 3 23 Triggered Versus Untriggered Displays 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 source 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
275. rkings on the product Consult the product manual for further ratings information before making connections to the product Connect the ground lead of the probe to earth ground only Do not apply a potential to any terminal including the common terminal that exceeds the maximum rating of that terminal Do Not Operate Without Covers Do not operate this product with covers or panels removed Use Proper Fuse Use only the fuse type and rating specified for this product Avoid Exposed Circuitry Do not touch exposed connections and components when power is present Do Not Operate With Suspected Failures If you suspect there is damage to this product have it inspected by qualified service personnel Do Not Operate in Wet Damp Conditions Do Not Operate in an Explosive Atmosphere Keep Product Surfaces Clean and Dry Provide Proper Ventilation Refer to the manual s installation instructions for details on installing the product so it has proper ventilation General Safety Summary Symbols and Terms A A Electrostatic Discharge Terms in this Manual 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 Terms on the Product These terms may appear on the product DANGER indicates an injury h
276. ro for the source waveform in the Vertical menu When measuring the amplitude at DC remember that 1 VDC equals 1 Vrms and the display is in dB 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 3 163 Using Features for Advanced Applications Acquisition Mode Zoom and Interpolation 3 164 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 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 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 waveform Peak Detect and
277. robes available see your Tektronix Products Catalog for more information about a given probe 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 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 The P6339A buffered passive probe is designed to work with the TDS 694C The P6339A probe will provide the same 10 MQ performance as other high input resistance probes NOTE Most passive probes require the input impedance of the oscilloscope to be 1 MQ The TDS 694C is 50 Q only and will not work with these probes TDS 694C User Manual Appendix D Probe Selection 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 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
278. rtical Controls page 3 9 Zoom page 3 32 2 4 Horizontal Controls page 3 13 Ground Triggering page 3 39 Delay Triggering page 3 80 Edge Triggering page 3 47 Logic Triggering page 3 51 Pulse Triggering page 3 67 Cursor Measurements page 3 98 Color page 3 28 Display Settings page 3 23 Remote Communication page 3 137 Probe Calibration page 3 109 TDS 694C User Manual Operating Interface Maps Rear Panel Map Principal Power Switch Centronics Connector page 3 127 RS 232 Connector GPIB Connector page 1 7 Zip Drive page 3 126 page 3 127 page 3 137 VGA Output fa a E GD Ci POWER CO co Fuse Serial Number Power Connector Rear Panel Connectors Security Bracket page 1 6 page 1 6 AUX TRIGGER INPUT Provides Auxiliary Trigger Signal Input MAIN TRIGGER OUTPUT Provides Main Trigger TTL Output DELAYED TRIGGER OUTPUT Provides Delayed Trigger TTL Output TDS 694C 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 20 page 3
279. s 0 dB ground 0 volts or zero phase level 0 degrees or 0 radians from the readout Read the 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 3 174 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 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 TDS 694C User Manual Using Features for Advanced Applications TDS 694C User Manual 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 T
280. s and Setups To Set Up for Making Hardcopies 3 128 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 oscilloscope 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 To capture the gray scale information in DPO displays use BMP Color or EPS Image formats 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 Before you make a hardcopy you need to set up communications and hardcopy 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 gt UTILITY System main gt I O pop up gt Con
281. s 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 A N Tek Run 100kKS 5 Sample Enter Label eegee Name f i OK BCDEFGHIJKLMNOPQRSTUVWRY20123456789 2_ amp Accept Enter Char EE Delete Clear Dooa Figure 3 65 File System Labeling Menu TDS 694C User Manual Saving Waveforms and Setups 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 disk and 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 NOTE While a Zip drive is attached printing to the Centronics port is not allowed 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 rec
282. s1Polarity is the polarity of first crossing no default It can be rising or falling TDS 694C User Manual Appendix B Algorithms TDS 694C User Manual 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 floating point number with values between 0 0 and RecordLength 1 0 inclusive EndCycle MCross3 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 Appendix B Algorithms Measurement Algorithms Amplitude Area Cycle Area 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
283. se 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 16 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 23 i D Tek Run 250kS 5 Sample Palettes Normal Bold Hardcopy Preview Monochrome Persistence Palettes Oloo oj AEREE change ap Restore Normal Colors Colors Settings lt Color gt Gpp Figure 3 16 Display Menu Setting TDS 694C User Manual Acquiring and Displaying Waveforms Choose a Palette Change the Palette Colors TDS 694C User Manual 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 2 Select one of the available palettes in the side menu Choose 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 Spectr
284. 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 in another trigger source Logic triggers are available on the main trigger system only 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 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 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
285. ser Manual 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 will also remove from the display any automated measurements being made on that waveform 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 2 shows the order of priority 1 CH1
286. settings 1 Press the Save Recall SETUP button to display the Setup menu see Fig ure 3 1 Press the button directly below the Recall Factory Setup menu item 2 Press the button to the right of the OK Confirm Factory Init side menu item 3 Press the SET LEVEL TO 50 button front panel to be sure the oscilloscope triggers on the input signal The TDS 694C Oscilloscopes 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 To determine which channel is currently selected check the channel readout It shows the selected channel in inverse video 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 1 a Tek Run 100kKS 5 Sample Recall Factory LOO IDID ID Factory Init cat ei H Pea eee aa ile Saved Current Factory Utilities Setup Setup Setu Dlo Figure 3 1 The Channel Readout TDS 694C User Manual Acquiring and Displaying Waveforms To Select and Remove Waveforms Waveform Priority TDS 694C U
287. sition Sequence 3 23 Stop After 3 22 3 151 Stop After Limit Test Condition Met 3 151 Template Source 3 148 V Limit 3 149 ACQUIRE MENU button 3 22 3 148 Acquiring and Displaying Waveforms 3 5 Acquisition 3 18 Glossary 1 Interval Glossary 1 Mode envelope 3 20 Modes Average 3 20 Peak detect 3 20 Sample 3 20 Readout 3 22 TDS 694C User Manual Acquisition mode Choosing an 3 17 Acquisition modes How to select 3 22 Active cursor Glossary 1 Active voltage probes D 3 active Saved waveform status 3 121 Advanced applications Features for 3 147 Algorithms B 1 Aliasing 3 24 3 167 Glossary 1 Amplitude 3 90 Glossary 1 AND Glossary 2 AND Main Trigger menu 3 59 3 61 Applications derivative math waveforms 3 174 FFT math waveforms 3 155 integral math waveforms 3 179 Area 3 90 Glossary 2 Attenuation Glossary 2 External 3 13 Auto Main Trigger menu 3 51 Automated Measurements Snapshot of 2 25 Automated measurements 2 20 3 90 of derivative math waveforms 3 176 procedure 3 176 of FFT math waveforms 3 162 of integral math waveforms 3 183 Automatic trigger mode 3 43 Glossary 2 Autosave Save Recall Waveform menu 3 124 Autoset 2 15 3 6 Glossary 2 Default settings 3 7 How to execute 3 6 AUTOSET button 2 15 AUX TRIGGER INPUT BNC 2 5 Auxiliary trigger 3 42 Average acquisition mode 3 20 Glossary 2 Average mode
288. sition mode If you are unsure how to select Average see Selecting an Acquisition Mode on page 3 20 3 Once you have selected a source select a destination for the template press Template Destination side gt Ref1 Ref2 Ref3 or Ref4 TDS 694C User Manual 3 146 Using Features for Advanced Applications TDS 694C User Manual Tek Run NAMS sample Limit Test Template Template Source chi Template Destination Refi V Limit 4omaiv H Limit 4omdiv 200mv M50 0us Chi zoomy a i i f i f ore Template Mode eign Stop After Limit Limit Test RR Signal Limit Test Sample N R S button Setup Sources Raina arn Oooo Scc Figure 3 79 Acquire Menu Create Limit Test Template 4 5 Press V Limit side Enter the vertical voltage tolerance value using the general purpose knob or keypad 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 When you have finished specifying the limit test template press OK Store Template sid
289. st 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 7 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 O O VERTICAL zoom HORIZONTAL A SCALE lt SCALE gt 7z WAVEFORM OFF Figure 2 7 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 694C User Manual Tutorial Autoset the Oscilloscope 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 displa
290. 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 47 m To logic trigger based on an input pattern state or setup hold violation see Triggering Based on Logic on page 3 51 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 67 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 Triggers determine when the oscilloscope stops acquiring and displays a waveform They help create meaningful waveforms from unstable jumbles or blank screens See Figure 3 23 The oscilloscope has three types of triggers edge logic pulse 3 39 Trigge
291. t 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 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 Glossary 3 Glossary Glossary 4 Digitizing The process of converting a continuous analog signal such as a waveform to a set of discrete numbers represen
292. t step 1 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 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 3 108 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 Probe Functions main gt Cal Probe side 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 59 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 side 10 Wait for gain compensation to complete one to three minutes When gain compensation completes the following actions occur m The clock icon will disappear TDS 694C User Manual Measuring Waveforms m If offset compensation is required for the probe
293. t 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 33 for the steps to set the horizontal lock feature To Select the You also can select Delayed Runs After Main or Delayed Triggerable Use the Delayed Time Base 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 Find More Information 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 16 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 32 Choosing an Acquisition Mode 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 section 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
294. tached data line and trigger all modules on trigger 3 Set the TLA Logic Analyzer with a short record length and continuous run 4 Start the TLA Logic Analyzer TDS 694C setup 1 Press SAVE RECALL SETUP gt Recall Factory Setup main OK Confirm Factory Init side 2 Set Channel 1 VERTICAL scale to 200 mV div 3 Set the HORIZONTAL scale to 200 ns div 3 65 Triggering on Waveforms 3 66 4 Select the trigger value press TRIGGER MENU gt pop up gt Source main TLA Cross Trigger side 5 Press the TRIGGER MENU Mode amp Holdoff main Normal side 6 Press the TRIGGER MENU gt Type main gt Edge pop up gt Slope main Select the negative __ edge from the side menu NOTE The TLA Logic Analyzer system trigger is a negative going edge NOTE The TLA Logic Analyzer should now be repetitively triggering on the rising edge of the signal and sending a trigger to the TDS 694C The rising edge of the signal should be displayed some where on the TDS 694C screen 7 Adjust the TLA Logic Analyzer s Cross Trigger delay until the rising edge of the signal is at the center of the graticule 8 Increase the TDS 694C oscilloscope s HORIZONTAL scale to a faster time div setting Then adjust the TLA Logic Analyzer s Cross Trigger delay at the same time to keep the rising edge of the signal at the center of the graticule 9 At the faster time div settings the jitter on the TLA
295. 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 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 TDS 694C User Manual Appendix B Algorithms Fall Time as THF TLF High HighR ef LowRef Low Figure B 2 Fall Time 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 Frequency Timing measurement The reciprocal of the period Measured in Hertz Hz where 1 Hz 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 fif Using the min max measurement technique High Max TDS 694C User Manual Appendix B Algorithms Low Maximum Mean Mean dBm Minimum B 10 0 lowest voltage reference value calculated See High Low on page B 1 Using the min max measurement technique Low Min Amplitude
296. te How to set up 3 77 3 88 Trigger Status menu 3 143 Trigger timeout How to set up 3 81 3 88 Trigger width How to set up 3 76 3 88 Triggering on Waveforms 3 41 True for less than Main Trigger menu 3 59 True for more than Main Trigger menu 3 59 Index 13 Index Type Logic Main Trigger menu Logic 3 57 3 61 3 62 Pulse 3 77 Type Pulse Main Trigger menu 3 71 Type Main Trigger menu 3 49 3 50 3 76 3 81 Pulse 3 73 U Undershoot Glossary 7 user Saved setup status 3 118 UTILITY button 3 23 3 110 3 130 3 141 Utility Menu OK Erase Ref amp Panel Memory 3 119 Tek Secure Erase Memory 3 119 Utility menu 3 23 3 130 Configure 3 23 3 130 3 141 Foot Switch RUN STOP 3 23 GPIB 3 141 Hardcopy 3 141 Hardcopy Talk Only 3 130 T O 3 23 3 130 Off Bus 3 141 Port 3 141 System 3 23 3 130 Talk Listen Address 3 141 V V Limit Acquire menu 3 149 Variable Persistence Display menu 3 26 Vectors 3 25 Vectors Display menu 3 25 Vertical Bar cursors 3 101 Glossary 12 Offset 3 13 Position 3 11 3 12 Readout 3 10 Scale 3 11 SCALE knob 2 14 3 11 System 2 14 Vertical deskew 3 111 Glossary 3 Vertical menu Cal Probe 3 111 Coupling 3 13 Deskew 3 111 External Attenuation 3 13 Fine Scale 3 13 Offset 3 13 Position 3 13 Set to Zero 3 13 VERTICAL MENU button 2 18 Index 14 Vertical position for DC cor
297. the More menu without creating a Math waveform OK Create Math wim LOIOIDIC O I 11110 1 Figure 3 83 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 Vrms 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 3 166 provides in depth information on setup for phase displays TDS 694C User Manual 3 156 Using Features for Advanced Applications TDS 694C User Manual 10 11 12 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 Hamming Very good window for resolving frequencies that are very close to the same value with somewhat improved amplitude accuracy over the rectangular
298. the math operator press Set operator to side repeatedly to cycle it through the choices Supported operators are and NOTE If you select for multiply in step 4 the cursor feature will measure amplitude in the units volts squared VV rather than in volts V a Tek Run 100kS 5 Sample Change Math Definition Set ist Source to chi i i p Set A T iia EE a g wei sod operator to oe 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 OK Create ingle WfimiDT EUAS iii PET Math Math OII JO SSES Figure 3 81 Dual Waveform Math Main and Side Menus 3 152 TDS 694C User Manual 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 key
299. 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 13 Actual High Frequency Waveform gt 3 22 Apparent Low frequency Waveform Due to Aliasing Sampled P oints Figure 3 13 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 TDS 694C User Manual Acquiring and Displaying Waveforms 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 to avoid 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 or Peak Detect 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 Customizing the Display Change Display Settings Select the Dis
300. tical Bar Cursors Paired Cursors Figure 3 53 Cursor Types Horizontal bar cursors measure vertical parameters typically volts Vertical bar cursors measure horizontal parameters typically time or frequency Paired cursors measure both vertical parameters typically volts and horizontal parameters typically time simultaneously Look at Figure 3 53 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 3 100 for more information 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 3 150 Cursor Modes There are two cursor modes independent and tracking See Figure 3 54 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 TDS 694C User Manual 3 99 Measuring Waveforms Independent Mode Tracking Mode Cursor Readouts 3 100 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
301. ting 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 DPO acquisition mode A mode that increases the waveform capture rate to up to 200 000 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 This display mode emulates the display of an analog oscilloscope 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 Extinction Ratio The ratio of High optical power to Low optical power 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 TDS 694C User Manual Glossary GND TDS 694C User Manual Frequency A timing measurement that is the reciprocal of the period Measured in Hertz H
302. tion HD Hard disk drive Add a hard disk R5 Extended Warranty Standard Accessories Optional Accessories A 2 Oscilloscope comes with a 5 year extended warranty The oscilloscope comes standard with the accessories listed in Table A 2 Table A 2 Standard accessories Accessory Part number User Manual with programmer disk 063 3060 XX 071 0473 XX Reference Manuals 020 2313 XX Technical Reference Performance Verification and Specifications 071 0496 XX Probes No probes standard Front Cover 200 3696 01 Accessory Pouch TDS 654C TDS 684C TDS694C TDS 700D 016 1268 00 U S Power Cord 161 0230 01 Run S top footswitch Run Stop 260 1189 02 Adapter footswitch 013 0312 00 Deskew Fixture 679 4809 00 You can also order the optional accessories listed in Table A 3 Table A 3 Optional accessories Accessory Part number Service Manual 071 0495 XX Oscilloscope Cart K420 Rack Mount Kit for field conversion 016 1236 00 Accessory Pouch 016 1268 00 TDS 694C User Manual Appendix A Options and Accessories Table A 3 Optional accessories cont Accessory Part number 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 1214 00 RS 232 Cable 012 1298 00 Accessory Probes Table A 4 lists the recommended probes for each oscilloscope Descriptions of each probe follow the table Table A 4 Rec
303. tions Trigger Modes and Trigger Holdoff on page 3 41 This feature provides the ability to cross trigger a TDS 694C oscilloscope with the system Trigger Out signal from a TLA Series Logic Analyzer For precise timing measurements a user can connect a TDS 694C oscilloscope to a TLA Logic Analyzer and take advantage of the best attributes of both instruments The TDS 694C and TLA Logic Analyzer complement each other because of their unique strengths The TDS 694C oscilloscope offers high accuracy timing measurements with a maximum sample rate of 10 GS s per channel The TDS 694C oscilloscope can capture very fast signal events with a 3 GHz trigger bandwidth However using a 4 channel oscilloscope can be time consuming when looking at a 64 bit bus A better alternative would be a TLA Logic Analyzer The TLA Logic Analyzer has TDS 694C User Manual Triggering on Waveforms TDS 694C User Manual the ability to look at hundreds of digital signals simultaneously up to 680 inputs can be captured and measured The TLA Logic Analyzer can evaluate several conditions simultaneously evaluate complex combinations of events and execute more extensive combinations of actions Cross triggering is very useful when measuring between multiple channels Cross triggering a TDS 694C with a TLA Logic Analyzer allows you to visually align the trigger points of both instruments The timing reference for both instruments is now the TLA Logic Analyzer trigger po
304. tionships between two waveforms XYZ format A display format that compares the voltage level of two waveform records point by point as in XY format The displayed waveform intensity is modulated by the CH 3 Z waveform record Ea 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 Zip drive An optional external disk drive you connect to the Centronix port You can save and recall waveforms acquisitions image histograms setups and hardcopies to an attached Iomega Zip drive TDS 694C User Manual Glossary 12 Index A AC line voltage trigger input 3 42 AC Main Trigger menu 3 51 Accept Glitch Main Trigger menu 3 73 Accessories A 1 Optional A 2 A 6 Probes A 3 Software A 5 Standard A 2 A 5 Accuracy Glossary 1 Acquire menu 3 22 Average 3 22 Average mode 3 148 Compare Ch1 to 3 150 Compare Ch2 to 3 150 Compare Ch3 to 3 150 Compare Ch4 to 3 150 Compare Math1 to 3 150 Compare Math2 to 3 150 Compare Math3 to 3 150 Create Limit Test Template 3 148 Envelope 3 22 H Limit 3 149 Hardcopy if Condition Met 3 151 Limit Test 3 151 Limit Test Condition Met 3 151 Limit Test Setup 3 150 3 151 Limit Test Sources 3 150 Limit Testing 3 148 OK Store Template 3 149 Ring Bell if Condition Met 3 151 RUN STOP 3 23 RUN STOP Foot Switch 3 23 Sample 3 22 Single Acqui
305. tronics port to the hardcopy device See Figure 3 70 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 Oscilloscope PC Compatible Centronics or GPIB Cable RS 232 Cable Figure 3 70 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 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 3 135 Saving Waveforms and Setups 3 136 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 w
306. u 3 31 Channel Glossary 2 Readout 2 6 3 8 3 35 Reference Indicator 2 6 3 8 Selection buttons 2 17 3 9 Index 2 Trigger input 3 42 Channel readout 2 6 Channel reference indicator Glossary 3 Channel probe deskew 3 111 Glossary 3 Channels Selecting 3 8 Circuit loading Glossary 3 Class Glitch Main Trigger menu 3 71 Class Main Trigger menu 3 76 3 81 Pattern 3 57 Runt 3 73 Setup Hold 3 62 Slew Rate 3 77 State 3 61 Classes Pulse triggers 3 70 CLEAR MENU button 2 3 2 8 2 13 2 22 2 23 3 98 Clear Spool Hardcopy menu 3 135 Clipping derivative math waveforms 3 177 FFT math waveforms 3 165 how to avoid 3 165 3 177 3 183 integral math waveforms 3 183 Clock Source Main Trigger menu 3 62 Collision Contrast Color menu 3 33 Color 3 30 How to set 3 30 Color Deskjet 3 129 Color Matches Contents Color menu 3 32 3 33 Color menu 3 30 Bold 3 31 Change Colors 3 31 Collision Contrast 3 33 Color 3 31 3 32 3 33 Color Matches Contents 3 32 3 33 Hardcopy 3 31 Hue 3 31 Lightness 3 32 Map Math 3 32 Map Reference 3 33 Math 3 32 Monochrome 3 31 Normal 3 31 Options 3 33 Palette 3 31 Persistence Palette 3 31 Ref 3 33 Reset All Mappings To Factory 3 34 Reset All Palettes To Factory 3 34 Reset Current Palette To Factory 3 34 Reset to Factory Color 3 31 Restore Colors 3 33 Saturation 3 32 TDS 694C User Manu
307. ude voltage measurement NegativeOvershoot Amplitude Note that this value should never be negative unless High or Low are set out of range Timing measurement The distance time between MidRef default 50 amplitude points of a negative pulse If MCross1 Polarity then NegativeWidth MCross2 MCross1 else NegativeWidth MCross3 MCross2 Waveform Start See Mean dBm on page B 10 Amplitude measurement The absolute difference between the maximum and minimum amplitude PeaktoPeak Max Min B 11 Appendix B Algorithms Period Phase Timing measurement Time taken for one complete signal cycle The reciprocal of frequency Measured in seconds Period MCross3 MCross1 Timing measurement The amount of phase shift expressed in degrees of the target waveform cycle between the MidRef crossings of two different wave 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 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 MidRefCr
308. uts 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 TDS 694C User Manual Measuring Waveforms Select Cursor Speed Select Time Units To Find More Information 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 adjust the distance of the solid cursor relative to the dashed cursor Press SELECT again to resume tracking 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 You can choose to display vertical bar cursor results
309. val Use for fastest acquisition rate This is the default mode Slolololelole e _ e aT mal 0 ee des Peak Detect L K 0 Ne D P Ko IN 3 iinet aaas y x y Uses highest and lowest samples in 0 two intervals Use to reveal aliasing and for glitch detection Provides the benefits of enveloping with the speed of a single acquisition l lolelelelele 4 Su Multiple Waveform Acquisitions Three Acquisitions from One Source Acquisition Waveform Drawn Mode on CR Acquisition 1 2 3 a HHHH th 0 a Finds highest and To Uses Peak Detect Mode for Each Acquisition lowest record points over 0 many acquisitions Use to reveal variations in the signal across time Sloltstototl ape Average 0 Hin fo n Calculates average value for a eee 0 Uses Sample Mode for Each Acquisition each record point over 0 many acquisitions Use to reduce apparent noise in a repetitive signal Figure 3 10 How the Acquisition Modes Work TDS 694C User Manual 3 19 Acquiring and Displaying Waveforms Checking the Acquisition Readout Acquisition R eadout Selecting an Acquisition Mode Stop After 3 20 To determine the acquisition sampling rate the acquisition state running or stopped and the acquisition mode check the Acquisition readout at the top of the display See Figure 3 11 The state Run shows the sample rate and acquisition mode The state
310. vanced Applications Integral Math Waveform Source Waveform 1_ __ Tek Run 5 00MS s Sample Math Change Math waveform definition No Extended Processing Average 2 chi soomvaQ 3 M 10 0ps Chi 520mV Oloo DUE 5 00uvs _ _ 10 05 i Bania ee Mathi Math2 Matha diff ch FFr ch Ege e Ref2 Ref3 Ref4 Dlo Figure 3 93 Integral Math Waveform To Take Cursor Once you have displayed your integrated math waveform use cursors to measure Measurements its voltage over time 1 TDS 694C User Manual Be sure MORE is selected lighted in the channel selection buttons and that the integrated math waveform is selected in the 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 to the top or to any amplitude level 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 level you choose 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 94 3 179 Us
311. vertical and horizontal knobs to scale and position the unmagnified waveform in the box 3 35 Acquiring and Displaying Waveforms Zoomed Magnified Waveforms t _ lt Nonzoomed Waveforms with Box Indicators at Corners Denoting the Selected Graticule Dual Zoom a Waveform 3 36 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 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 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 ee S Sample mmj 50 0mVvo i Preview ic a q oomva B Ee age oa soou Chi F olololoo electe Graticule tower Gpp Figure 3 21 Dual Window Preview Mode To select Dual Zoom press ZOOM
312. 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 15 The normalized mean If the waveform source is from an optical probe this can give average optical power Mean dBm 10 0 logzg Mean 0 001 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 TDS 694C User Manual Appendix B Algorithms Negative Duty Cycle Negative Overshoot Negative Width Optical Power Peak to Peak TDS 694C User Manual Timing measurement The ratio of the negative pulse width to the signal period expressed as a percentage NegativeWidth is defined in Negative Width below If Period 0 or undefined then return an error NegativeWidth Period a NegativeDutyCycle Amplit
313. 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 Width Triggering Press TRIGGER MENU gt Type main Pulse pop up gt Class main Width pop up Select the Source Press TRIGGER MENU gt Type main gt Pulse pop up gt Source main 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 gt Class main gt Width pop up gt Polarity main Positive or Negative side 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 Pulse pop up gt Class main 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 TDS 694C User Manual Triggering on Waveforms 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
314. y including selecting the color of the display elements Coupling Waveforms to the Oscilloscope To Find More Information TDS 694C User Manual 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 The TDS 694C Oscilloscopes ships without probes Tektronix recommends you order and use the P6249 P6339 or P6158 probes These probes take advantage of the higher bandwidth of these models Tektronix also offers a variety of optical probes differential probes adapters and BNC cabling and connectors to couple a variety of signal sources to the input channels See Options and Accessories on page A 1 or your Tektronix Sales representative for the specific items offered for signal coupling To find a procedure for changing the coupling and input impedance settings see To Change Vertical Parameters on page 3 11 To find a list of available probes see Accessory Probes on page A 3 To find a guide for selecting probes for a variety of applications see Appen dix D Probe Selection on page D 1 Acquiring and Displaying Waveforms Setting up Automatically Autoset and Reset 3 4 To Autoset the Oscilloscope The TDS 694C Oscilloscopes can automatically obtain and display a stable waveform of usable size It can also be reset to its factor
315. y and then to autoset the display 1 To create an unstable display slowly turn the trigger MAIN LEVEL knob see Figure 2 8 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 A TRIGGER MAIN LEVEL MAIN LEVEL Knob TRIG D READY DELAYED TRIG arm TRIGGER MENU SET LEVEL TO 50 Figure 2 8 TRIGGER Controls 2 Press AUTOSET see Figure 2 9 and observe the stable waveform display NOTE The oscilloscope triggers on the input signal Sometimes the oscilloscope triggers on high frequency signal components that are not visible using the current setup You may see these signal components at higher HORIZONTAL SCALE settings You can reduce these signal components using shorter probe ground and signal leads TDS 694C User Manual 2 15 Tutorial SAVE RECALL APPLICATION gt MENU _ ACQUIRE MENU AUTOSET WAVEFORM MEASURE HARDCOPY RUN STOP AUTOSET Button SNCS I Gy EC UTILITY CURSOR DISPLAY CE Ce GS QQ VERTICAL A HORIZONTAL 77 SHIFT Figure 2 9 AUTOSET Button Location Figure 2 10 shows the display after pressing AUTOSET If necessary you can adjust the waveform now by using the knobs discussed earlier in this example a Tek Run Oe Sample OlIoloo gill oomo scons Chi
316. y 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 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 Autoset may change vertical position in order to position the waveform appropriately If an offsetable level II probe is attached AUTOSET will adjust offset to center the signal in the dynamic range of the probe TDS 694C User Manual Acquiring and Displaying Waveforms List of Autoset Defaults TDS 694C User Manual Table 3 1 lists the autoset defaults Table 3 1 Autoset defaults Control Changed by autoset to Selected channel Numerically lowest of the displayed channels Acquire Mode Sam
317. y menu 3 23 FORCE TRIG button 3 47 Format File Utilities menu 3 128 Format Hardcopy menu 3 131 Frame Display menu 3 28 Frequency 2 21 3 91 Glossary 5 Front Cover removal 1 7 Front panel 2 4 Full Display menu 3 28 Function Cursor menu 3 103 3 104 Fuse 1 6 2 5 G Gated Measurements 3 94 Glossary 5 Gating Measure menu 3 95 General purpose high input resistance probes D 1 General purpose knob 2 7 2 23 Glossary 5 Glitch trigger 3 69 3 70 Glossary 5 How to set up 3 71 Glitch Main Trigger menu 3 73 Goes FALSE Main Trigger menu 3 59 3 61 Goes TRUE Main Trigger menu 3 59 3 61 GPIB 2 5 3 139 3 142 Glossary 5 Connecting to 3 141 Interconnect cabling 3 140 Interface requirements 3 139 Procedures for using 3 141 Protocols 3 139 Selecting and configuring the port 3 141 Typical configuration 3 140 GPIB Programming F 1 GPIB Hardcopy menu 3 132 GPIB Utility menu 3 141 Graticule 3 28 Glossary 5S Graticule measurements 3 105 Graticule Display menu 3 28 Grid Display menu 3 28 Ground coupling Glossary 5 GROUP 1 GROUP 2 buttons 3 35 Index 5 Index H H Bars Cursor menu 3 103 3 104 H Limit Acquire menu 3 149 Hamming window 3 159 Hanning window 3 159 Hardcopy 3 129 Glossary 5 DPO displays 3 130 How to print controller 3 137 How to print no controller 3 134 How to save to disk 3 136 How to set u
318. yed Trigger menu 3 88 Set to 50 Horizontal menu 3 17 Set to 50 Main Trigger menu 3 46 3 52 3 73 3 82 Set to 90 Horizontal menu 3 17 Set to ECL Delayed Trigger menu 3 88 Set to ECL Main Trigger menu 3 52 3 73 3 78 3 82 Set to TTL Delayed Trigger menu 3 88 Set to TTL Main Trigger menu 3 52 3 73 3 78 3 82 Set to Zero Vertical menu 3 13 Set Hold Trigger 3 54 Setting Up for the Examples 2 9 Settings Display menu 3 25 3 30 Setup menu 2 10 3 8 Setup Hold trigger Maximum hold time NOTE 3 55 Negative setup or hold times 3 55 Positive setup or hold times 3 55 Trigger point location 3 55 Setup Hold trigger 3 53 How to setup 3 62 3 88 Setups Save and recall 3 117 Shipping C 1 Side menu Glossary 11 Side menu buttons 2 3 Glossary 11 Signal Path Compensation 1 5 3 110 Sin x x interpolation 3 19 3 28 Glossary 6 Sin x x interpolation Display menu 3 28 Single Acquisition Sequence Acquire menu 3 23 SINGLE TRIG button 3 24 3 47 Single Wfm Math More menu 3 153 Single Shot sampling 3 19 Slew rate setting How derived 3 80 Slew Rate Trigger 3 71 Slew rate trigger 3 69 Glossary 10 Glossary 11 600 ps limitation 3 79 3 88 7 5 ns limitation 3 79 3 88 How to set up 3 77 3 88 Slope Glossary 11 Slope Delayed Trigger menu 3 87 Slope Main Trigger menu 3 52 Slope Trigger 3 45 Snapshot Readout 3 99 Snapshot of Measurements 2 25
319. z 1 cycle per second High 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 Low The value used as 0 whenever High Ref Mid Ref and Low Ref values are needed as in fall 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 Maximum Mean Minimum Negative Duty Cycle Negative Overshoot Negative Width Peak to Peak Voltage measurement The maximum amplitude Typically the most positive peak voltage Measured over the entire waveform or gated region Voltage measurement The arithmetic mean over the entire waveform or gated region Voltage measurement The minimum amplitude Typically the most negative peak voltage Measured over the entire waveform or gated region 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 NegativeWiath Peri
320. z 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 trigger 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 High The value used as 100 in automated measurements whenever high ref mid ref an

User Manual TDS 694C Digital Real-Time Oscilloscope 071-0473-00

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