Page 1 User Manual TDS 820 Digitizing Oscilloscope 070-8512-04 This document supports firmware version 2.00e and above.
Page 2 Instrument Serial Numbers Each instrument manufactured by Tektronix has a serial number on a panel insert or tag, or stamped on the chassis. The first letter in the serial number designates the country of manufacture. The last five digits of the serial number are assigned sequentially and are unique to each instrument.
Page 3 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.
Page 5 DANGER indicates a personal injury hazard immediately accessible as one reads the marking. This symbol appears in manuals: Static Sensitive Devices These symbols appear on equipment: DANGER Protective ATTENTION High Voltage ground (earth) Refer to terminal manual TDS 820 User Manual...
Page 6: Power Source
Safety Specific Precautions Observe all of these precautions to ensure your personal safety and to prevent damage to either the digitizing oscilloscope or equipment con nected to it. To avoid potential hazards, use this product only as specified. Power Source The digitizing oscilloscope is intended to operate from a power source that will not apply more than 250 V between the supply conductors or be...
Page 7 Safety Do Not Operate in Explosive Atmospheres The digitizing oscilloscope provides no explosion protection from static discharges or arcing components. Do not operate the digitizing oscilloscope in an atmosphere of explosive gases. TDS 820 User Manual...
Page 8 Safety viii Safety...
Page 9: Table Of Contents
........... . 3 21 TDS 820 User Manual...
Page 10 Contents Hardcopy ........... 3 26 Help .
Page 11 The TDS 820 Programmer Manual describes using a computer to control the digitizing oscilloscope through the GPIB interface. The TDS TDS 820 Reference gives you a quick overview of how to operate your digitizing oscilloscope. The TDS 820 Service Manual provides information for maintaining and servicing your digitizing oscilloscope.
Page 12 Preface Conventions In the Getting Started and Reference sections, you will find various proce dures which contain steps of instructions for you to perform. To keep those instructions clear and consistent, this manual uses the following conven tions: Names of front panel controls and menu labels appear in boldface print. Names also appear in the same case (initial capitals, all uppercase, etc.) in the manual as is used on the oscilloscope front panel and menus.
Page 14 Use a seventy five percent (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 represen tative. Remove loose dust an the outside of the oscilloscope with a lint free cloth.
Page 15: Product Description
8 GHz maximum repetitive analog bandwidth in TDS 820 Option 1D; 6 GHz in the standard TDS 820. Pretrigger view (not available with Option 1D). Acquisition channels The TDS 820 has two. You may use and display all channels simultaneously. Two14 bit digitizers.
Page 16: Start Up
90 to 250 VAC rms, continuous range, 47 Hz to 63 Hz, and may require up to 300 W. 4. Connect the proper power cord from the rear panel power connector (Figure 1 1) to the power system. TDS 820 User Manual...
Page 17 Start Up Power Connector Principal Power Switch Fuse Figure 1 1: Rear Panel Controls Used in Start Up Power On 1. Check that the rear panel principal power switch is on (Figure 1 1). The principal power switch controls all AC power to the instrument. 2.
Page 18: Self Test
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.
Page 19: Setting Up For The Examples
Setting Up for the Examples All the examples use the same setup. Once you perform this setup, you do not have to change the signal connections for any of the other examples. When you finish, the setup should appear as shown in Figure 1 3. To 1 MHz TEST SIGNAL OUTPUT on Rear Panel...
Page 20 CAUTION To prevent damage to the inputs do not attempt to measure any signals greater than 3 V peak-to-peak with the TDS 820 with Option 1D (6 V peak to peak with the standard TDS 820). TDS 820 User Manual...
Page 21: Example 1: Displaying A Waveform
Example 1: Displaying a Waveform In this first example you learn about resetting the digitizing oscilloscope, using the autoset function, and displaying and adjusting a waveform. Resetting the All examples begin by resetting the digitizing oscilloscope to a known, factory default state. That is useful when you begin a new task and need to Digitizing start fresh"...
Page 22 3. Press the button to the right of the OK Confirm Factory Init side menu item. NOTE This manual uses the following notation to represent the sequence of selections you made in steps 1, 2 and 3: Press save/recall SETUP Recall Factory Setup (main) OK Confirm Factory Init (side). TDS 820 User Manual...
Page 23 Example 1: Displaying a Waveform Using Autoset When you first connect a signal to a channel and display it, the signal dis played may not be usable. Use the digitizing oscilloscope's autoset function when that happens and you will quickly get a meaningful display. For example, the factory default settings are useful for many of the signals you will be viewing with your digitizing oscilloscope.
Page 24 Figure 1 8 shows the display after pressing AUTOSET for an instrument with delay lines. NOTE If you have an instrument without delay lines (TDS 820 Option 1D), your display may appear slightly different, but the following steps will still function as described.
Page 25 Example 1: Displaying a Waveform The time base readout shows that the time base is showing a horizontal scale of 500 ns/div. The M" indicates that it is the main time base. A D" indicates a delayed time base. The channel readout indicates that channel 1 (Ch1) is selected. Its vertical scale is also displayed.
Page 26 300 mV amplitude. To adjust the size and placement of the Waveform Display waveform use the front panel knobs. Figure 1 11 shows the main VERTICAL and HORIZONTAL sections of the front panel. Each section has SCALE and POSITION knobs. 1 13 TDS 820 User Manual...
Page 27 Example 1: Displaying a Waveform Figure 1 11: The VERTICAL and HORIZONTAL Controls 1. Turn the vertical SCALE knob a few clicks in first one direction, then the other. Observe the change in the displayed waveform and the channel readout at the bottom of the display. 2.
Page 28: Example 2: Multiple Waveforms
Adding a Waveform The VERTICAL section of the front panel contains the channel selection buttons. On the TDS 820 these are CH 1, CH 2, and MORE (Figure 1 12). Figure 1 12: The Channel Buttons and Lights Each of the channel (CH) buttons has a light above its label. Right now, the CH 1 light is on.
Page 29 Example 2: Multiple Waveforms The display shows a second waveform, which represents the signal on channel 2 superimposed on the first waveform. There are several other important things to observe: The channel readout on the display now shows the settings for both Ch1 and Ch2.
Page 30 Because channel 2 has no signal, AUTOSET may have chosen an inappropriately sensitive vertical scale setting, and you may see random noise. To reduce this random noise, turn the vertical scale knob counter clockwise until channel 2 appears as you would like. 1 17 TDS 820 User Manual...
Page 31 Example 2: Multiple Waveforms Side Menu Title Figure 1 14: The Menus After Changing Channels 2. Press Fine Scale (main) to adjust the channel 2 vertical scale. 3. Use the numeric keypad to set the vertical scale to 125 mV per division. Enter 125, then SHIFT, then m (the shifted 9 key).
Page 32 The channel (CH) lights now indicate channel 1. Channel 1 has become the selected channel. 5. Press the WAVEFORM OFF button again to remove channel 1's wave form. When you remove the last waveform, all the CH lights turn off. 1 19 TDS 820 User Manual...
Page 33: Example 3: Automated Measurements
Example 3: Automated Measurements In this example you learn how to use the automated measurement system to get numeric readouts of important waveform characteristics. 1. If you are not continuing from the previous example, follow the instruc tions on page 1 6 under the heading Setting Up for the Examples." 2.
Page 34 Observe that all four measurements are displayed. Right now, they cover a part of the graticule area, including the displayed waveforms. 5. To move the measurement readouts outside the graticule, press CLEAR MENU (Figure 1 17). 1 21 TDS 820 User Manual...
Page 35 Example 3: Automated Measurements Figure 1 17: Four Simultaneous Measurement Readouts Removing The Measure menu lets you remove measurements you no longer want displayed. You can remove any one measurement or you can remove them Measurement all with a single menu item. Readouts Press MEASURE Remove Measrmnt (main)
Page 36 The numeric keypad also provides multipliers for engineering exponents, such as m for milli, M for mega, and m for micro. To enter these multiplier values, press the SHIFT button, then press the multiplier. 1. Press Low Ref (side). 1 23 TDS 820 User Manual...
Page 37 Example 3: Automated Measurements 2. On the numeric keypad, press the 2 button, the 0 button, and the EN TER ( ) button. This step sets the low measurement reference to 20%. Observe that the rise time value has changed. Now you want to return the display to its original state.
Page 38: Example 4: Saving Setups
3. Press the SETUP button to display the Setup main menu (see Fig ure 1 19). Press the Save Current Setup main menu button. 1 25 TDS 820 User Manual...
Page 39 Example 4: Saving Setups Figure 1 19: Save/Recall Setup Menu 4. To store the current instrument settings into that setup location, press one of the To Setup side menu buttons. There are more setup locations than can be listed at one time in the side menu.
Page 41 The acquisition system, which lets you select the modes for converting analog data into digital form (Figure 2 2). See page 2 17. +0.25 V +0.25 V -0.25 V -0.25 V Figure 2 2: Acquisition: Input Analog Signal, Sample, and Digitize TDS 820 User Manual...
Page 42: Overview
Overview The waveform scaling and positioning system, which changes the dimensions of the waveform display. Scaling waveforms involves in creasing or decreasing their displayed size (Figure 2 3). Positioning means moving them up, down, right, and left on the display. See page 2 21.
Page 43: At A Glance
To Operate a Menu shows how to select and use menus including pop ups. Menu Map shows each of the main menus (the menus that appear on the bottom of the display) and the buttons that access them. TDS 820 User Manual...
Page 44 At a Glance Front Panel Map Left Side Side Menu Buttons, page 2 8 ON/STBY Switch, Main Menu Buttons, CLEAR MENU page 1 3 page 2 8 Removes Menus from the Display Operating Basics...
Page 45 3 93 Waveform Math, page 3 97 Zoom, page 3 100 Key Pad, Probe Interface, Horizontal Controls, page 2 8 page 3 60 page 3 35 Triggering Controls, General Purpose page 3 85 Knob, page 2 8 TDS 820 User Manual...
Page 46 Principal Power Switch, page 1 3 Fuse, Power Connector, Connector, page 1 3 page 1 3 page 3 71 TDS 820 Serial Number, 1 MHz TEST SIGNAL INTERNAL CLOCK OUTPUT - Security page D 1 OUTPUT- (Provides internal clock signal output...
Page 47: Display Map
3 93 page 3 87 Horizontal time base position, page 3 35 The main menu with Horizontal scale choices of major and time base actions, page 2 8 type, page 3 35 TDS 820 User Manual...
Page 48 At a Glance To Operate A Menu 1. Press front panel menu button. 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 ad justable value (shown in reverse video), adjust it with the general purpose knob or...
Page 49 To Operate A Pop Up Menu Press Press here to to display pop ups remove menus from screen Press it again to make selection A pop up selection changes the other main menu titles (see page 2 12) TDS 820 User Manual...
Page 50 At a Glance Menu Map Press these buttons: To bring up these menus: Acquire Menu see page 3 2) Application Menu (see the Programmer manual for more details Cursor Menu see page 3 8) Display Menu see page 3 14 ) Hardcopy Menu (see page 3 26) Horizontal Menu...
Page 51 Measure Menu (see page 3 47) More Menu (see page 3 97 ) Save/Recall Setup Menu (see page 3 75 ) Save/Recall Waveform Menu (see page 3 77) Status Menu (see page 3 84) 2 11 TDS 820 User Manual...
Page 52 At a Glance Press these buttons: To bring up these Menus: Utility Menu - Graphics (see page 3 21) Utility Menu - Config see pages 3 76 and 3 29) Utility Menu - I/O see page 3 71) Utility Menu - Calibration see the Performance Verification Instruction manual) Utility Menu - Diagnostics...
Page 53: Triggering
The normal trigger source is either one of the input channels. The channel you select as a trigger source functions whether it is displayed or not. (Instruments without delay lines cannot use the input channels as a trigger source.) 2 13 TDS 820 User Manual...
Page 54: External Trigger
Triggering Internal Clock TDS 800 oscilloscopes allow you to use the internal clock as a trigger source. The internal clock runs at a rate that you can set from a front panel menu or a remote controller. The internal clock signal is also available from a rear panel connector for triggering external devices.
Page 55: Slope And Level
(see Figure 2 7). Positive Going Edge Negative Going Edge Trigger Level Can be Adjusted Vertically Trigger Slope Can be Positive or Negative Figure 2 7: Slope and Level Controls Help Define the Trigger 2 15 TDS 820 User Manual...
Page 56 Triggering The digitizing oscilloscope lets you set the main trigger level with the trigger LEVEL knob. For More See Triggering, on page 3 85. Information 2 16 Operating Basics...
Page 57: Acquisition
500, 1000, 2500, 5000, and 15,000 points. Sampling Sampling is the process of converting the analog input signal to digital for display and processing. The two general methods of sampling are real time and equivalent time. 2 17 TDS 820 User Manual...
Page 58 Acquisition TDS 800 Digitizing Oscilloscopes use equivalent time sampling. In equiva lent time (ET) sampling the oscilloscope acquires samples over many repeti tions of the event (Figure 2 9). NOTE Equivalent time sampling requires repetitive signals to give mean ingful results. TDS 800 Digitizing Oscilloscopes use a type of equivalent time sampling called sequential equivalent time sampling.
Page 59: Normal Mode
(see Figure 2 10). If waveform data exceeds the limits you have set, the digitizing oscilloscope can ring a bell, make a hardcopy, or stop and wait for you to take some action. 2 19 TDS 820 User Manual...
Page 60 Acquisition Figure 2 10: Comparing a Waveform to a Limit Template For More See Scaling and Positioning Waveforms, on page 2 21. Information See Acquisition Modes, on page 3 2. See Limit Testing, on page 3 41. 2 20 Operating Basics...
Page 61: Scaling And Positioning Waveforms
As you turn it counterclockwise the scale increases allowing you to see more of the waveform but with lower resolution. 2 21 TDS 820 User Manual...
Page 62 ±10 mV. Vertical offset, on the other hand, always provides a range of ±2 V (±1 V with the TDS 820 Option 1D), regardless of the scale. Vertical position changes the point about which the waveform expands or contracts when you change the scale.
Page 63 TRIG'D is on. Aliasing occurs because the oscilloscope is not acquiring with a high enough sample density to construct an accurate waveform record (Figure 2 12). Actual High Frequency Waveform Apparent Low Frequency Waveform Due to Aliasing Sampled Points Figure 2 12: Aliasing 2 23 TDS 820 User Manual...
Page 64 Scaling and Positioning Waveforms One simple way to check for aliasing is to slowly change the horizontal scale (time per division setting). If the shape of the displayed waveform changes drastically, you may have aliasing. To represent a signal accurately and avoid aliasing, you must sample the signal at least twice as fast as the highest frequency component in equiva lent time.
Page 65: Measurements
You can make automated measurements on the entire waveform record or just on a specific part. The gating option in the Measurement menu lets you use the vertical cursors to limit the measurement to a section of the wave form record. 2 25 TDS 820 User Manual...
Page 66: Cursor Measurements
Measurements The snapshot option in the Measurement menu lets you display almost all the measurements at once. You can read about snapshot in Measurement System, which begins on page 3 47. Amplitude measurements are made on vertical parameters. The units of such measurements are typically volts (sometimes %).
Page 67 Independent mode cursors operate as described earlier; that is, you move one cursor at a time (the active cursor) using the general purpose knob, and you use the TOGGLE button to toggle which cursor bar is active. (See Figure 2 15.) 2 27 TDS 820 User Manual...
Page 68 Measurements Selected Cursor Moves Only Both Cursors Move in Tandem Independent Mode Tracking Mode Figure 2 15: Cursor Modes Tracking mode cursors operate in tandem: you move both cursors at the same time using the general purpose knob. (See Figure 2 15.) To adjust the solid cursor relative to the dashed cursor, you push the TOGGLE button to suspend cursor tracking and use the general purpose knob make the ad justment.
Page 70: Overview
Cursor Measurements Display Modes Graphics Hardcopy Help Horizontal Control Limit Testing Measurement System Probe Interface Probe Selection Remote Communication Saving and Recalling Setups Saving and Recalling Waveforms Selecting Channels Status Triggering Vertical Control Waveform Math Zoom TDS 820 User Manual...
Page 71: Acquisition Modes
Acquisition Modes The acquisition system has several options for converting analog data into digital form. The Acquisition menu lets you determine the acquisition mode and how to start and stop acquisitions. Acquisition Readout The Acquisition readout at the top of the display (Figure 3 1) shows the state of the acquisition system (running or stopped).
Page 72: Acquisition Mode
Hint: To make large changes quickly with the general purpose knob, press the SHIFT button before turning the knob. When the light above the SHIFT button illuminates and the display says Coarse Knobs in the upper right corner, the general purpose knob speeds up significantly. TDS 820 User Manual...
Page 73 Acquisition Modes Stop After You can choose to acquire exactly one waveform sequence or to acquire waveforms continuously under manual control. Press SHIFT ACQUIRE MENU Stop After (main) RUN/STOP button only, Single Acquisition Sequence, or Limit Test Condition Met (side) (see Figure 3 3). Figure 3 3: Acquire Menu Stop After RUN/STOP button only lets you start or stop acquisitions by toggling the RUN/STOP button.
Page 74 Limit Test Sources main menu item. See Limit Testing on page 3 41 for further details. For More See Acquisition, on page 2 17. Information See Limit Testing, on page 3 41. TDS 820 User Manual...
Page 75: Autoset
Autoset The autoset function lets you quickly obtain and display a stable waveform of usable size. Autoset automatically sets up the front panel controls based on the characteristics of the input signal. That is much faster and easier than a manual control by control setup. Autoset makes adjustments in these areas: Acquisition, Display,...
Page 76 Numerically lowest of the displayed channels Without delay lines: Unchanged Trigger Level Midpoint of data for the trigger source Trigger Slope Positive Trigger Holdoff Minimum Vertical Scale As determined by the signal level Vertical Offset To center the signal Zoom TDS 820 User Manual...
Page 77: Cursor Measurements
Cursor Measurements Use the cursors to measure the difference (either in time or voltage) be tween two locations in a waveform record. Cursors are 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.
Page 78 Press TOGGLE 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. TDS 820 User Manual...
Page 79 Cursor Measurements Cursor Readouts 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 whether you are using H Bars or V Bars. H Bars: the value after D shows the voltage difference between the cursors.
Page 80 (Useful for Locating Cursors Outside the Display) Cursor Readout (Paired) Non selected Cursor (Dashed Vertical Bar; Solid Horizontal Bar) Selected Cursor (Solid Vertical Bar; Solid Horizontal Bar) Figure 3 8: Paired Cursor Menu and Readouts 3 11 TDS 820 User Manual...
Page 81 Cursor Measurements Operation To take cursor measurements press the CURSOR button to display the Cursor menu (Figure 3 7). Function You can select the type of cursors you want using the Function menu item. Press CURSOR Function (main) H Bars, V Bars, Paired, or Off (side). Mode You can select the cursor mode you want using the Function menu item.
Page 82 See the TDS Family Option 2F Instruction Manual, if your oscilloscope has the advanced DSP math option, for information on cursor units with inte grated, differentiated, and FFT waveforms. See Probe Functions, on page 3 96. 3 13 TDS 820 User Manual...
Page 83: Display Modes
Display Modes The digitizing oscilloscope can display waveform records in different ways. The Display menu lets you adjust the oscilloscope display style, intensity level, graticule, and format. Operation Press DISPLAY to show the Display menu. Display Style Select the Style menu item to select the display style for the waveform record (Figure 3 10).
Page 84: Acquisition 2
Figure 3 11: Display Menu Intensity All intensity adjustments operate over a range from 20% (close to fully off) to 100% (fully bright). Contrast operates over a range from 100% (no contrast) to 250% (intensified portion at full brightness). 3 15 TDS 820 User Manual...
Page 85 NOTE The Trigger Bar feature was disabled for initial releases of the TDS 820 Digitizing Oscilloscope. 1. Press DISPLAY Readout (main). 2. Toggle Trigger Bar Style (side) to select either the short or the long trigger bar or to turn the trigger bar off.
Page 86 To change the filter type, follow these steps. Press DISPLAY Filter (main) Sin(x)/x Interpolation or Linear Inter polation (side). Graticule Type To change the graticule: Press DISPLAY Graticule (main) Full, Grid, Cross Hair, or Frame (side) (Figure 3 13). 3 17 TDS 820 User Manual...
Page 87 Display Modes Figure 3 13: Display Menu Graticule 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. Format There are two kinds of format: YT and XY. YT is the conventional oscilloscope display format.
Page 88 XY format is a dot only display, although it can have persistence. The Vector style selection has no effect when you select XY format. 3 19 TDS 820 User Manual...
Page 89 Display Modes You cannot display Math waveforms in XY format. They will disappear from the display when you select XY. For More See Acquisition on page 2 17. Information 3 20 Reference...
Page 90: Graphics 3
The first time you see the crosshair cursor, the horizontal lines terminate in arrowheads, indicating that the general purpose knob controls hori zontal motion. Rotate the general purpose knob and watch the cursor move horizontally across the display. 3 21 TDS 820 User Manual...
Page 91 Graphics 4. Now press TOGGLE. The arrowheads move to terminate the vertical lines, and the general purpose knob now moves the cursor vertically across the display. Push TOGGLE and rotate the general purpose knob until you have placed the crosshair cursor where you want your first line to start. Drawing 5.
Page 92 Crosshair are equivalent. Removing Points 1. If you add a point in error, you can remove it. Press Delete Last Point (side) to remove the last point you added from the list of points. 3 23 TDS 820 User Manual...
Page 93 Graphics 2. If you press Delete Last Point repeatedly, you can remove all the points you added in the reverse order from the order in which you added them. 3. You can clear the display of all lines by removing all the points in the list. To do so, press Delete All Points (side).
Page 94 When you recall the setup, it also restores these items. For More See Saving and Recalling Setups, on page 3 75. Information 3 25 TDS 820 User Manual...
Page 95: Hardcopy 3
EPS Mono and Color formats are compatible with the Tektronix Phaser Color Printer, HPGL is compatible with the Tektronix HC100 Plotter, and Epson is compatible with the Tektronix HC200 Printer.
Page 96 Option 13, the only choice is GPIB. (If your instrument is equipped with Option 13, see the TDS Family Option 13 Instruction Manual for setting up hardcopy over the RS 232 and Centronics ports.) 3 27 TDS 820 User Manual...
Page 97 Hardcopy Landscape Format Portrait Format Figure 3 19: Hardcopy Formats The Port main menu item lets you specify the output channel to send your hardcopy through. The only choice is GPIB. Printing the Hardcopy You can print a single hardcopy or send additional hardcopies to the spool (queue) while waiting for earlier hardcopies to finish printing.
Page 98 (The format when using the keypad is day.month. For example, use 23.6 for the 23 of June.) 7. Repeat steps 5 and 6 to set other parameters as desired. 3 29 TDS 820 User Manual...
Page 99 Hardcopy 8. Press OK Enter Date/Time (side) to put the new settings into effect. This sets the seconds to zero. NOTE When setting the clock, you can set to a time slightly later than the current time and wait for it to catch up. When current time catches up to the time you have set, pressing OK Enter Date/Time (side) synchronizes the set time to the current time.
Page 100 TDS and the RS 232 or Centronics hardcopy device (see Figure 3 22). For example, a National Instruments GPIB PRL (a GPIB to Cen tronics converter) will permit you to make screen prints on a Tektronix HC200 Dot Matrix printer with just a Centronics port.
Page 101 Oscilloscope Figure 3 23: Connecting the TDS and Hardcopy Device Via a PC If your controller is PC compatible and it uses the Tektronix GURU or S3FG210 (National Instruments GPIB PCII/IIA) GPIB package, you can operate this setup as follows: 1.
Page 102 Your hardcopy device should now print a picture of the digitizing oscillo scope screen. For More See Remote Communication, on page 3 71. Information See the TDS Family Option 13 Instruction Manual, Tektronix part number 070 8567 00 (Option 13 equipped instruments only). 3 33 TDS 820 User Manual...
Page 103: Help
Help The on line help system provides brief information about each of the digitiz ing oscilloscope controls. Operation To use the on line help system Press HELP to provide on screen information on any front panel button, knob or menu item (see Figure 3 24). When you press that button, the instrument changes mode to support on line help.
Page 104: Horizontal Control 3
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 speeds up significantly. Figure 3 25: Horizontal Controls 3 35 TDS 820 User Manual...
Page 105 Horizontal Control Horizontal Readouts At the top of the display, the Record View shows the size and location of the waveform record and the location of the trigger relative to the display (see Figure 3 26). The Time Base readout at the lower right of the display shows the time per division and time base position settings and the time base (main or delayed) being referred to (see Figure 3 26).
Page 106 Pressing Delayed Position sets the general purpose knob or keypad to set the delayed time base position, but does not change the view displayed. The main time base position appears in the readout below the menu item. 3 37 TDS 820 User Manual...
Page 107 Horizontal Control Time Base Position You can also set the main and delayed time base positions using the Time Base Position menu item. The time base position is the time from the trigger event to the first point in the waveform record. Press HORIZONTAL MENU Time Base Position (main) Main Position...
Page 108 See Zoom, on page 3 100 for the steps to set the horizontal lock feature. Manual Deskew The TDS 820 allows you to align a signal horizontally one channel at a time using manual deskew. Use manual deskew to align the signal from one channel precisely with the signal from the other.
Page 109: Scaling And Positioning Waveforms 2
Horizontal Control For More See Scaling and Positioning Waveforms, on page 2 21. Information See Zoom, on page 3 100. 3 40 Reference...
Page 110: Limit Testing 3
Average acquisition mode. If you are unsure how to do this, see Acquisition Modes on page 3 3. Once you have selected a source, select a destination for the template. 2. Press Template Destination (side) Ref1, Ref2, Ref3, or Ref4. 3 41 TDS 820 User Manual...
Page 111 Limit Testing Figure 3 29: Acquire Menu Create Limit Test Template 3. Create the envelope by specifying the amount of variation from the template that you will tolerate. Tolerance values are expressed in frac tions 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.
Page 112 (see Figure 3 31). 1. Press SHIFT ACQUIRE MENU Limit Test Setup (main) to bring up a side menu of possible actions. 3 43 TDS 820 User Manual...
Page 113 Limit Testing Figure 3 30: Acquire Menu Limit Test Sources 2. Ensure that the side button corresponding to the desired action reads If you want the digitizing oscilloscope to send a hardcopy command when waveform data exceeds the limits set, toggle Hardcopy if Condition Met (side) to ON.
Page 114 The position of the waveform template will track that of the waveform. You may turn ZOOM on or off to suit your application. 3 45 TDS 820 User Manual...
Page 115 Limit Testing Multiple Waveform Comparisons When comparing one or more waveforms, each against a common template or against its own template, consider the following operating characteristics: You should turn ZOOM on. (Press ZOOM On (side).) You can use horizontal and vertical magnification or not as suits your application. You should set Horizontal Lock to None in the Zoom side menu (press ZOOM and toggle Horizontal Lock to None).
Page 116: Measurements 2
Voltage over time measurement. The area over the first cycle in the waveform, or the first cycle in the gated region, in volt seconds. Area mea sured above ground is positive; area below ground is negative. 3 47 TDS 820 User Manual...
Page 117 Measurement System Table 3 3: Measurement Definitions (Cont.) Name Definition Cycle Mean Voltage measurement. The arithmetic mean over the first cycle in the waveform, or the first cycle in the gated region. Cycle RMS Voltage measurement. The true Root Mean Square voltage over the first cycle in the wave form, or the first cycle in the gated region.
Page 118 PositiveDutyCycle + PositiveWidth 100% Period Positive Over Voltage measurement over the entire wave shoot form or gated region. Max * High PositiveOvershoot + 100% Amplitude 3 49 TDS 820 User Manual...
Page 119 Measurement System Table 3 3: Measurement Definitions (Cont.) Name Definition Positive Width Timing measurement of the first pulse in the waveform or gated region. The distance (time) between MidRef (default 50%) amplitude points of a positive pulse. Rise time Timing measurement. Time taken for the lead ing edge of the first pulse in the waveform or gated region to rise from a Low Ref value (de fault = 10%) to a High Ref value (default =...
Page 120 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 wave form. 3 51 TDS 820 User Manual...
Page 121 Measurement System Your digitizing oscilloscope helps identify such situations by displaying a low signal amplitude or low resolution warning message. You can minimize most noise problems by changing the acquisition mode to averaging to reduce random noise. Removing Measurements The Remove Measrmnt selection provides explicit choices for removing measurements from the display according to their readout position.
Page 122 Press MEASURE High Low Setup (main) Histogram or Min Max (side) (Figure 3 35). If you select Min Max, you may also want to check and/or revise values using the Reference Levels main menu. 3 53 TDS 820 User Manual...
Page 123 Measurement System Figure 3 35: Measure Menu High Low Setup Reference Levels You can set the vertical reference levels of the measurement system with the Reference Levels main menu item. Once you define these levels, the digitizing oscilloscope will use them for all measurements requiring those levels.
Page 124 Measure Delay to. 2. Press the side menu button repeatedly or turn the general purpose knob to choose the delay to waveform. The choices are: Ch1, Ch2, Math1, Math2, Math3, Ref1, Ref2, Ref3, and Ref4. 3 55 TDS 820 User Manual...
Page 125 Measurement System Figure 3 37: Measure Delay Menu Delay To Delay Edges The main menu item Edges lets you specify which edges you want the delayed measurement to be made between. Press MEASURE Select Measrmnt (main) Delay (side) Delay To (main) Edges (side).
Page 126 To use snapshot, obtain a stable display of the waveform. Pressing AUTO SET may help. 1. Press MEASURE SNAPSHOT (main). 2. Press either SNAPSHOT (main) or AGAIN (side) to take another snap shot. 3. Push Remove Measrmnt. 3 57 TDS 820 User Manual...
Page 127 Measurement System Snapshot Display Figure 3 39: Snapshot Menu and Readout Considerations When Taking Snapshots Be aware of the following items when using snapshot: Be sure to display the waveform properly before taking a snapshot. Snapshot does not warn you if a waveform is improperly scaled (clipped, low signal amplitude, low resolution, etc.).
Page 128 Measurement System For More See Measurements, on page 2 25. Information See Cursor Measurements on page 3 8. See Appendix C: Algorithms, on page C 1. See Probe Functions, on page 3 96. 3 59 TDS 820 User Manual...
Page 129: Probe Interface 3
Probe Interface The PROBE POWER connector on the digitizing oscilloscope front panel provides a TEKPROBE compatible SMA interface between the digitizing oscilloscope and probes that support TEKPROBE capability with SMA connectors, such as the P6206 probe. The interface connector provides power to active probes. It also allows the digitizing oscilloscope to read probe configuration data, and can allow you to set vertical offset at the probe tip, for probes that have offset capability.
Page 130 This allows you to use the probe's larger dynamic range. For example, the dynamic range of the TDS 820 is 2 V peak to peak (1 V peak to peak for Option 1D). It has an additional offset capability of ±2 V (±1 V for Option 1D).
Page 131 -10 V 10X Probe Figure 3 42: TDS 820 Vertical Scale and Probe Attenuation Factor If the 10X probe includes the probe tip offset function and its offset capabili ties are ±10 V, you can move this 20 V window up or down an additional 10 volts, allowing you to look at signals as high as 0 V to 20 V peak to peak, or as low as -20 V to -0 V peak to peak (see Figure 3 43).
Page 132 To avoid damaging the digitizing oscilloscope, the signal you wish to look at divided by the probe attenuation factor must be less than or equal to the ±6 V maximum input to the TDS 820 (±3 V for Option 1D instruments).
Page 133: Probe Selection
Probe Selection The probes available for your digitizing oscilloscope are useful for a wide variety of tasks. However, for special measurement situations you some times need different probes. This section helps you select the right probe for the job. The following section discusses the importance of ground lead inductance for measuring signals accurately.
Page 134 To select the probe by application, use Table 3 5. There are five types of probes: passive, active, current, optical, and time to voltage probes. 3 65 TDS 820 User Manual...
Page 135 Zo probes are useful for measurements up to 40 V. NOTE These voltages are much higher than you can measure with the TDS 820, which is damaged by input voltages greater than 6 V peak to peak (3 V peak to peak for Option 1D instruments). Active Voltage Probes Active voltage probes, sometimes called FET"...
Page 136: Current Probes
Probe Selection NOTE This dynamic range is greater than that provided by the TDS 820, whose range extends from 1.25 mV to 2 V (1.25 mV to 1 V for Option 1D instruments). Two common classes of active probes are:...
Page 137 Probe Selection Use a current probe by clipping its jaws around the wire carrying the current that you want to measure. (That is not like an ammeter, which you must connect in series with the circuit.) Because current probes are non invasive, with loading typically in the mW to low W range, they are especially useful where low loading of the circuit is important.
Page 138 CT 2: 1.2 kHz to 200 MHz, 50 W input Needs SMA to BNC adapter. Time to Voltage Converter TVC 501 Time delay, pulse width and period measurements Manual probe scaling required Probe does not use TDS 800 probe interface. 3 69 TDS 820 User Manual...
Page 139 Probe Selection Another way to classify probes is by application. Different applications demand different probes. Use Table 3 5 to select a probe for your applica tion. Table 3 5: Probes by Application Telecommu Industrial Consumer/ High Energy Certification, nications & Electronics Computer Pulsed Power/...
Page 140: Remote Communication
Besides the base protocols, Tektronix has defined codes and formats for messages to travel over GPIB. Each device that follows these codes and formats, such as the TDS 820, supports standard commands. Use of instru ments that support these commands can greatly simplify development of GPIB systems.
Page 141 Figure 3 47: Typical GPIB Network Configuration Cables You must use an IEEE Std 488.1 1987 GPIB cable (available from Tektronix) to connect two GPIB devices. Connector A 24 pin GPIB connector is located on the oscilloscope rear panel. The connector has a D type shell and conforms to IEEE Std 488.1 1987.
Page 142 To set up remote communications, you must physically cable your oscillo scope to the controller and correctly set your oscilloscope parameters. Plug an IEEE Std 488.2 1987 GPIB cable (available as Tektronix part number 012 0991 00) into the GPIB connector on your oscilloscope rear panel and into the GPIB port on your controller (see Figure 3 49).
Page 143 Remote Communication The GPIB Configuration Menu Figure 3 50: Utility Menu For More See Hardcopy, on page 3 26. Information See TDS 820 Programmer Manual. See the TDS Family Option 13 Instruction Manual (Option 13 equipped instruments only). 3 74 Reference...
Page 144: Saving And Recalling Setups
2. Choose one of the ten storage locations from the side menu To Setup 1, To Setup 2, ... (see Figure 3 51). Now the current setup is stored in that location. Figure 3 51: Save/Recall Setup Menu 3 75 TDS 820 User Manual...
Page 145: Example 4: Saving Setups 1
Saving and Recalling Setups Recalling a Setup To recall a setup, press SETUP Recall Saved Setup (main) (Recall Setup 1, Recall Setup 2 ... (side). Recalling a setup will not change the menu that is currently displayed. If you recall a setup labeled factory in the side menu, you will recall the factory setup.
Page 146: Saving And Recalling Waveforms
This feature finds use where this digitizing oscilloscope is used to gather security sensitive data, such as is done for research or development projects. See Deleting All Setups and Waveforms" on page 3 76. 3 77 TDS 820 User Manual...
Page 147: Recalling A Waveform
Saving and Recalling Waveforms Figure 3 52: Save Waveform Menu Deleting All Waveforms and Setups The simultaneous removal of all stored waveforms and setups using the feature called Tek Secure is described under Saving and Recalling Setups. See Deleting All Setups and Waveforms" on page 3 76. Recalling a Waveform To recall a waveform: Press MORE...
Page 148 Saving and Recalling Waveforms Figure 3 53: More Menu For More See Selecting Channels, on page 3 80. Information 3 79 TDS 820 User Manual...
Page 149: Selecting Channels
Selecting Channels The selected channel is the channel that the digitizing oscilloscope applies all waveform specific activities to (such as measurements or vertical scale and position). Channel Readout The channel readout shows the selected channel in inverse video in the lower left corner of the display (see Figure 3 54).
Page 150 Trigger menu. Removing Waveforms From the Display The WAVEFORM OFF button turns OFF the display of the selected channel waveform. It will also remove from the display any automated measurements being made on that waveform. 3 81 TDS 820 User Manual...
Page 151 Selecting Channels When you turn off a waveform, the digitizing oscilloscope automatically selects the next highest priority waveform. Figure 3 56 shows how the oscilloscope prioritizes waveforms. 1. CH1 2. CH2 3. MATH1 4. MATH2 5. MATH3 6. REF1 7. REF2 8.
Page 152 Selecting Channels 3 83 TDS 820 User Manual...
Page 153: Status
Status The Status menu lets you see information about the oscilloscope state. Operation To operate the Status menu: Press SHIFT STATUS System, Trigger, Waveforms, or I/O (side). The Status menu is unusual because it only has a side (vertical) menu. There are no choices along the main (horizontal) axis.
Page 154: Triggering
When finished, the trigger circuitry returns to normal operation. You can also set the level to 50% in the Trigger menu under the main menu item Level. 3 85 TDS 820 User Manual...
Page 155 Triggering Readouts The digitizing oscilloscope has display readouts and status lights dedicated to monitoring the trigger circuitry. Trigger Status Lights There are two status lights in the Trigger control area (see Figure 3 59) indicating the state of the trigger circuitry. The lights are labeled TRIG'D and READY.
Page 156 Triggering Trigger Level and Trigger Slope Figure 3 60: Example Trigger Readouts Location of Trigger Position Relative to the Display and Waveform Record Figure 3 61: Record View Readout Showing Trigger Position 3 87 TDS 820 User Manual...
Page 157 Triggering Trigger Level Indicators In addition to the numerical readouts of trigger level, there are also graphic indicators of trigger level that you can optionally display. These indicators are the long trigger level bar, and the short trigger level bar. Figure 3 62 shows the short style trigger level bar.
Page 158 Knobs in the upper right corner, the general purpose knob speeds up significantly. Slope To select the slope that the trigger will occur on: Press TRIGGER MENU Slope (main). Alternatives for slope are rising edge and falling edge. 3 89 TDS 820 User Manual...
Page 159 Triggering Mode To select the trigger mode: Press TRIGGER MENU Mode (main) Auto or Normal (side) (see Figure 3 64). In Auto mode the oscilloscope acquires a waveform after 50 ms has elapsed even if a trigger does not occur. In Normal mode the oscilloscope acquires a waveform only if there are valid triggers.
Page 160 The maximum possible trigger holdoff is 2 s. 3 91 TDS 820 User Manual...
Page 161 Triggering Figure 3 66: Trigger Menu Holdoff The actual holdoff time is visible below the Actual Holdoff side menu item. This menu item is dimmed because you cannot set the actual holdoff direct ly. The oscilloscope calculates Actual Holdoff from the requested holdoff and the other time base parameters mentioned above.
Page 162: Vertical Control
If you want the POSITION knob to move faster, press SHIFT. When the light above the SHIFT button is on and the display says Coarse Knobs in the upper right corner, the POSITION knob speeds up significantly. 3 93 TDS 820 User Manual...
Page 163 Vertical Control Vertical Readouts The Vertical readout at the lower part of the display shows each displayed channel (the selected channel is in inverse video), and its volts per division setting (see Figure 3 68). Selected Channel and Vertical Scale Figure 3 68: Vertical Readouts Vertical Menu The Vertical menu lets you select the offset for the selected waveform.
Page 164 NOTE Autoset may change vertical offset to position the waveform ap propriately. When offset is not set to 0 V, the ground reference indicator points to ground plus the offset, and not to ground. 3 95 TDS 820 User Manual...
Page 165 Vertical Control Fine Scale Press VERTICAL MENU Fine Scale (main) to make fine adjustments to the vertical scale using the general purpose knob or the keypad. The side menu item shows the setting of the Fine Scale parameter. That readout and the display's vertical readout will show any changes to the volts per division.
Page 166: Waveform Math
Figure 3 70: More Menu Math1, Math2, and Math3 1. Press MORE Math1, Math2, or Math3 (main) to select the waveform that you want to display or change (Figure 3 70). 3 97 TDS 820 User Manual...
Page 167 Waveform Math NOTE If your digitizing oscilloscope contains Option 2F, Advanced DSP Math, the menu item FFT will be at the same brightness as the menu items Single Wfm Math and Dual Wfm Math; otherwise, FFT will be dimmed. See the TDS Family Option 2F Instruction Manual for information on FFTs and other advanced math wave forms.
Page 168 For More If your oscilloscope contains option 2F, you can also create integrated, differentiated, and Fast Fourier Transform waveforms. If your oscilloscope Information contains the option, see the TDS Family Option 2F Instruction Manual. 3 99 TDS 820 User Manual...
Page 169: Zoom
Zoom At times, you may want to expand or compress a waveform on the display without changing the acquisition parameters. You can do that with the zoom feature. Zoom and When you zoom in on a waveform on the display, you expand a portion of it. The digitizing oscilloscope must show more points for that portion than it Interpolation has acquired.
Page 170 (Figure 3 74). (Waveforms displayed from an input channel are live; math and reference waveforms are not live.) All all waveforms displayed (channels, math, and/or reference) can be magnified and positioned horizontally at the same time. 3 101 TDS 820 User Manual...
Page 171 Zoom Only the selected waveform (the top one) changes size Figure 3 73: Zoom Mode with Horizontal Lock Set to None All displayed input channels change size Figure 3 74: Zoom Mode with Horizontal Lock Set to Live 3 102 Reference...
Page 172 Zoom Horizontal Position Tracking Horizontal Position Zoom Horizontal Gain Press ZOOM Off (side) to return to normal (non zoom) operation. For Further See Acquisition, on page 2 17. Information See Display Modes, on page 3 14. 3 103 TDS 820 User Manual...
Page 173 Zoom 3 104 Reference...
Page 175: Appendix A: Options And Accessories
Options available for the digitizing oscilloscope are described below. Options A1-A5: International Power Cords Besides the standard North American, 110 V, 60 Hz power cord, Tektronix ships any of five alternate power cord configurations with the oscilloscope when ordered by the customer.
Page 176 Appendix A: Options and Accessories Option 1D: Delete Delay Lines and Trigger Pickoff With its delay lines removed, the TDS 820 features a higher bandwidth and slightly reduced noise. However, it cannot display any pretrigger information, nor can either input channel be used as the trigger source.
Page 177 Appendix A: Options and Accessories Option 1S: SIU 800 Static Isolation Unit With this option, Tektronix ships two SIU 800 Static Isolation Units. The SIU 800 protects the sampler from damage due to static discharge from circuit boards and cables.
Page 178: Accessory Probes
Tables 3 4 and 3 5, on pages 3 69 and 3 70, describe optional accessory probes that you can use with your digitizing oscilloscope. Accessory Software The following optional accessories are Tektronix software products recom mended for use with your digitizing oscilloscope: Table A 4: Accessory Software...
Page 179: Appendix B: Specifications
General Product Tektronix TDS 800 Digitizing Oscilloscopes are portable, two channel instru ments suitable for use in a variety of test and measurement applications and Description systems. Key features include:...
Page 180 Appendix B: Specifications Appendices...
Page 181: Nominal Traits
50 W nominal Ranges, Sensitivity 1 mV/div - 100 mV/div for Option 1D 2 mV/div - 200 mV/div for the delay line version of the TDS 820 Ranges, Offset, All Channels ±1.00 V at all volts per division settings for Option 1D ±2.00 V at all volts per division settings for the delay line version of...
Page 182 External Trigger 0.5 mV increments CH 1 or CH 2 Trigger 2 mV increments (for the delay line ver sion of the TDS 820 only) Internal Clock Out Square wave out into 50 W: -0.175 V to 0.100 V low level 0.850 V to 1.100 V high level...
Page 183 Either of two fuses may be used: a 0.25I 1.25I (UL 198.6, 3AG): 6 A FAST, 250 V, or a 5 mm 20 mm, (IEC 127): 5 A (T), 250 V. Each fuse type requires its own fuse cap. TDS 820 User Manual...
Page 184 Forced air circulation with no air filter Construction Material Chassis parts constructed of aluminum alloy; front panel constructed of plastic laminate; circuit boards constructed of glass laminate. Cabinet is aluminum and is clad in Tektronix Blue vinyl material. Finish Type Tektronix Blue vinyl clad aluminum cabinet...
Page 185: Performance Conditions
TDS 820 Range, Dynamic 1 V peak to peak AC 2 V peak to peak AC for the delay line version of the TDS 820 Input Resistance W ±0.5 W W ±1 W for the delay line version of the TDS 820 Accuracy, DC Gain ±0.7% ±0.005% (T...
Page 186 ))(offset - position Volts per division) +4 mV+(T )(0.2 mV/_C) (after vertical calibration) for the delay line version of the TDS 820 is the ambient temperature at which offset gain was adjusted. is the ambient temperature. T is the ambient temperature when a vertical compensation was performed.
Page 187 Accuracy = 30 ps + 0.001(10 ns + 1.5 ns) + 30 ps 0.457 = 20 + 11.5 +13.7 = 55.2 ps time intervals <500 ps measured at (time per division X the number of divisions) 500 ps. TDS 820 User Manual...
Page 188 CH 1 and CH 2 increasing to 150 mV peak to peak at 1.0 GHz for the delay line version of the TDS 820 Jitter, Trigger Delay 3 ps rms + 30 parts per million (ppm) of the selected delay...
Page 189 FCC Rules and Regulations,47 CFR Part 15, Subpart B, Class A Electrostatic Discharge Up to 8 kV with no change to control settings or impairment of nor mal operation Up to 15 kV with no damage that prevents recovery of normal op eration B-11 TDS 820 User Manual...
Page 190 Appendix B: Specifications B-12 Appendices...
Page 191 1.1:1 from DC to 6 GHz 1.3:1 from 6 GHz to 8 GHz 1.3:1 from DC to 6 GHz for the delay line version of the TDS 820 Crosstalk, Sine or Square Wave Input 1000:1 from DC to 8 GHz...
Page 192 Appendix B: Specifications Table B 14: Typical Characteristics Time Base System Name Description View Time, Pretrigger 1.5 ns for the delay line version of the TDS 820 Table B 15: Typical Characteristics Triggering System Name Description Pulse Width, Minimum Trigger External 0.25 ns...
Page 193 CAT II Local level mains (wall sockets). Equipment at this level includes appliances, portable tools, and similar products. Equipment is usually cord connected. CAT I Secondary (signal level) or battery operated circuits of electronic equipment. B 15 TDS 820 User Manual...
Page 194 Appendix B: Specifications B 16 Appendices...
Page 195: Appendix C: Algorithms
Appendix C: Algorithms The Tektronix TDS Series Digitizing Oscilloscope can take 27 automatic measurements. By knowing how the instrument makes these calculations, you may better understand how to use your instrument and how to interpret your results. Measurement The TDS Series Digitizing Oscilloscope uses a variety of variables in its calculations.
Page 196 Appendix C: Algorithms The oscilloscope calculates the histogram based High and Low values as follows: 3. It makes a histogram of the record with one bin for each of 256 vertical levels. 4. It splits the histogram into two sections at the halfway point between Min and Max (also called Mid).
Page 197 (or the gated region) of the opposite polarity of MCross1. This is MCross2. 3. Continuing from MCross2, find the next MidRefCrossing in the waveform record (or the gated region of the same polarity as MCross1. This is MCross3. TDS 820 User Manual...
Page 198 Appendix C: Algorithms MCross1 MCross3 (StartCycle) (EndCycle) MCross2 MidRef + (Hysteresis x Amplitude) MidRef MidRef - (Hysteresis x Amplitude) Figure C 1: MCross Calculations MCross1Polarity is the polarity of first crossing (no default). It can be rising or falling. StartCycle is the starting time for cycle measurements.
Page 199: Burst Width
For details of the integration algorithm, see page C 13. Cycle Mean 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. TDS 820 User Manual...
Page 200: Fall Time
Appendix C: Algorithms EndCycle Waveform(t)dt StartCycle CycleMean= (EndCycle * StartCycle) SampleInterval For details of the integration algorithm, see page C 13. Cycle RMS The true Root Mean Square voltage over one cycle. If StartCycle = EndCycle then CycleRMS = Waveform[Start]. Otherwise, EndCycle (Waveform(t))
Page 201 100% (highest) voltage reference value. (See High, Low" earlier in this section) Using the min max measurement technique: High = Max 0% (lowest) voltage reference value calculated. (See High, Low" earlier in this section) Using the min max measurement technique: TDS 820 User Manual...
Page 202 Appendix C: Algorithms Low = Min Maximum Amplitude (voltage) measurement. The maximum voltage. Typically the most positive peak voltage. Examine all Waveform[ ] samples from Start to End inclusive and set Max equal to the greatest magnitude Waveform[ ] value found. Mean The arithmetic mean for one waveform.
Page 203: Negative Duty Cycle
If MCross1Polarity = `-' then NegativeWidth = (MCross2 - MCross1) else NegativeWidth = (MCross3 - MCross2) Peak to Peak Amplitude measurement. The absolute difference between the maximum and minimum amplitude. PeaktoPeak = Max - Min TDS 820 User Manual...
Page 204 Appendix C: Algorithms Period Timing measurement. Time taken for one complete signal cycle. The recip rocal of frequency. Measured in seconds. Period = MCross3 - MCross1 Phase Timing measurement. The amount of phase shift, expressed in degrees of the target waveform cycle, between the MidRef crossings of two different waveforms.
Page 205: Positive Duty Cycle
Positive Width 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) C 11 TDS 820 User Manual...
Page 206: Rise Time
Appendix C: Algorithms Rise Time 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 C 3 shows a rising edge with the two crossings necessary to calcu late a Rise Time measurement.
Page 207 A and B are numbers between 0.0 and RecordLength-1.0 If A and B are integers, then: (W(i)) W(i ) 1) ) (W(i ) 1)) ) W(i) dt + s where s is the sample interval. C 13 TDS 820 User Manual...
Page 208 Appendix C: Algorithms Measurements on Time measurements on envelope waveforms must be treated differently from time measurements on other waveforms, because envelope waveforms 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.
Page 209 When Snapshot displays measurements, out of range warnings are NOT available. However, if you question the validity of any measure ment in the snapshot display, you can select and display the mea surement individually and then check for a warning message. C 15 TDS 820 User Manual...
Page 210 Appendix C: Algorithms C 16 Appendices...
Page 211: Appendix D: Packaging For Shipment
The shipping carton must be constructed of cardboard with 170 kg (375 lb) test strength. 2. If you are shipping the digitizing oscilloscope to a Tektronix field office for repair, attach a tag to the digitizing oscilloscope showing the instru ment owner and address, the name of the person to contact about the instrument, the instrument type, and the serial number (see page 2 6).
Page 212 Appendix D: Packaging for Shipment Appendices...
Page 213: Appendix E: Factory Initialization Settings
Cursor function Cursor mode Independent Cursor time units Seconds Display clock No Change Display format Display graticule type Full Display intensity - contrast 150% Display intensity - text Display intensity - waveform Display intensity - overall TDS 820 User Manual...
Page 214 Appendix E: Factory Initialization Settings Table E 1: Factory Initialization Defaults (Cont.) Control Changed by Factory Init to Display interpolation filter Sin(x)/x Display style Dots Display style Vectors Display trigger bar style Short Display trigger T" Display variable persistence 500 ms External Attenuation 1X and 0 dB Graphics - line display...
Page 215 15 ms Trigger level 0.0 V Trigger mode Auto Trigger slope Rising Trigger source External Input Vertical offset (all channels) Vertical position (all channels) 0 divisions. Vertical volts per division. (all 100 mV per division. channels) TDS 820 User Manual...
Page 216 Appendix E: Factory Initialization Settings Table E 1: Factory Initialization Defaults (Cont.) Control Changed by Factory Init to Zoom horizontal (all channels) 1.0X Zoom horizontal lock Live Zoom horizontal position 50% = 0.5 (the middle of the display) (all channels) Zoom state Zoom vertical (all channels) 1.0X...
Page 218 10X probe will attenuate, or reduce, the input voltage of a signal by a factor of 10. Values <1 represent gain rather than attenuation. Attenuation is also sometimes expressed in decibels. The relation ship between decibels and the attenuation ratio is: dB + 20 log Glossary 1 TDS 820 User Manual...
Page 219 Burst width A timing measurement of the duration of a burst. Channel One type of input used for signal acquisition. The TDS 820 has two channels. Channel Reference Indicator The indicator on the left side of the display that points to the position around which the waveform contracts or expands when vertical scale is changed.
Page 220 GPIB is also known as an IEEE 488 bus. It transfers data with eight parallel data lines, five control lines, and three handshake lines. Glossary 3 TDS 820 User Manual...
Page 221 Glossary Graticule A grid on the display screen that creates the horizontal and vertical axes. You can use it to visually measure waveform parameters. Hardcopy An electronic copy of the display in a format usable by a printer or plotter. High The value used as 100% in automated measurements (whenever high ref, mid ref, and low ref values are needed as in fall time and...
Page 222 Normal acquisition mode The oscilloscope creates a record point during each acquisition interval. The waveform record is displayed without averaging, envel oping, or other processing. This is the default mode of the acquisi tion. Glossary 5 TDS 820 User Manual...
Page 223 Glossary Normal trigger mode A mode on which the oscilloscope does not acquire waveform data unless a valid trigger event occurs. It waits for a valid trigger event before acquiring waveform data. Oscilloscope An instrument for making a graph of two factors. These are typically voltage versus time.
Page 224 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. Glossary 7 TDS 820 User Manual...
Page 225 Glossary Slope The direction at a point on a waveform. You can calculate the direc tion 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.
Page 227 Readout, 3 2 UTILITY, 3 21, 3 26, 3 73 Active cursor, Glossary 1 VERTICAL MENU, 1 16, 3 94 WAVEFORM OFF, 1 18, 3 19, 3 81 Active voltage probes, 3 66 3 67 Index 1 TDS 820 User Manual...
Page 228 Index ZOOM, 3 100 Mode, 2 27 Independent, 2 27 2 28 Buttons Tracking, 2 28 CH1, CH2 ..., 3 80 Paired, 2 27, 3 8 Channel selection, 1 15, 3 80 Readouts, 3 10 Main menu, 2 4 Speed, 3 13 Side menu, 2 4 Vertical bar, 2 27, 3 8 CURSOR button, 3 12...
Page 229 Saved waveform status, 3 77 GPIB, 2 6, 3 30 3 33, 3 71 3 74, Glossary 3 Encapsulated Postscript, 3 26 GPIB, Hardcopy menu, 3 27, 3 28 Envelope acquisition mode, 2 19, 3 3, Glossary 3 Index 3 TDS 820 User Manual...
Page 230 Index GPIB, Status menu, 3 84 Thinkjet, 3 27 TIFF, 3 27 GPIB, Utility menu, 3 73 Hardcopy, Utility menu, 3 73 Graphics, 3 21 3 25 Saving, 3 25 HELP button, 3 34 Graphics menu, 2 12, 3 21 Help system, 3 34 Close Polygon, 3 22 High, 3 48, Glossary 4...
Page 231 Maximum, 3 48, Glossary 5 ZOOM, 2 24 Maximum Sample Rate, Trigger menu, 3 92 Mean, 3 48, Glossary 5 MEASURE button, 3 51 Measure Delay menu, 3 55 Create Measrmnt, 3 56 Landscape, Hardcopy menu, 3 27 Index 5 TDS 820 User Manual...
Page 232 Index Delay To, 3 55 Width, 1 21, Glossary 5, Glossary 6 Edges, 3 56 Measurements, 2 25 2 28, 3 47 3 59 Measure Delay To, 3 55 Algorithms, C 1 C 16 OK Create Measurement, 3 56 Automated, 1 20, 2 25 Measure Delay To, Measure Delay menu, 3 55 Cursor, 2 26, 3 8 Gated, 3 52, Glossary 3...
Page 233 Differential active, 3 67 P6206 probe, 3 60 Fixtured active, 3 67 Packaging, D 1 Optional, A 2 Paired cursor, 2 27, 3 8 Passive voltage, 3 66 removed, A 2 Paired, Cursor menu, 3 12 Index 7 TDS 820 User Manual...
Page 234 Index Selecting, 3 64 3 70 Remove Measrmnt, Measure menu, 3 52, 3 57 Time to voltage converter, 3 68 Requested Holdoff, Trigger menu, 3 92 Type, 3 68 Reset Zoom Factors, Zoom menu, 3 103 Propagation delay, 3 48 Ring Bell if Condition Met, Acquire menu, 3 44 Rise time, 1 21, 3 50, Glossary 7 Rising edge, Trigger menu, 3 89...
Page 235 Start up, 1 3 Tracking, Cursor menu, 3 12 Static Isolation Unit, A 3 TRIG'D light, 3 86 Status menu, 3 84 Trigger, 2 13 2 16, 3 85, Glossary 8 Firmware version, 3 84 Index 9 TDS 820 User Manual...
Page 236 Index Autoset adjustments, 3 6 Configure, 3 26, 3 73 External, 2 14 GPIB, 3 73 Holdoff, 2 14 Hardcopy, 3 73 Internal clock, 2 14 Hardcopy (Talk Only), 3 26 Level, 2 13, 2 15, Glossary 8 I/O, 3 26, 3 73 Mode, 2 14 Off Bus, 3 73 Readout, 3 86, 3 87...
Page 237 Width, 1 21, Glossary 5, Glossary 6 Zoom menu Horizontal Lock, 3 101 On, 3 100 Reset Zoom Factors, 3 103 Zoom Off, 3 103 Zoom Off, Zoom menu, 3 103 XY format, 3 18 3 20, Glossary 8 Index 11 TDS 820 User Manual...
Page 238 Index Index 12 Index...

Tektronix TDS 820 User Manual

Quick Links

Related Manuals for Tektronix TDS 820

Summary of Contents for Tektronix TDS 820

Table of Contents