User Manual TDS 500C, TDS 600B & TDS 700C Digitizing Oscilloscopes 070-9869-00 This document applies for 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.
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.
Table of Contents General Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi xiii Related Manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Default Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Model References . . . . . . . . . . . . . . .
Table of Contents Triggering on Pulses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Communications Triggering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Delayed Triggering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–89 3–103 3–106 Measuring Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–113 Taking Automated Measurements . . .
Table of Contents List of Figures Figure 1–1: Rear Panel Controls Used in Start Up . . . . . . . . . . . . . . . Figure 1–2: ON/STBY Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–7 1–8 Figure 2–1: Connecting a Probe for the Examples (P6245 shown) . . Figure 2–2: SETUP Button Location . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2–3: The Setup Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2–4: Trigger Controls . . . . . . . . . . .
Table of Contents Figure 3–14: Equivalent-Time Sampling . . . . . . . . . . . . . . . . . . . . . . . Figure 3–15: How the Acquisition Modes Work . . . . . . . . . . . . . . . . . Figure 3–16: Acquisition Menu and Readout . . . . . . . . . . . . . . . . . . . . Figure 3–17: Acquire Menu — Stop After . . . . . . . . . . . . . . . . . . . . . . Figure 3–18: Aliasing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 3–19: Display Menu — Style . . . . . . . . . . . . . . .
Table of Contents Figure 3–51: Delayed Triggerable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 3–52: How the Delayed Triggers Work . . . . . . . . . . . . . . . . . . . Figure 3–53: Delayed Trigger Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 3–54: Histogram, Graticule, Cursor and Automated Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 3–55: Measurement Readouts with Statistics . . . . . . . . . . . . . .
Table of Contents vi Figure 3–87: Initial Help Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 3–88: Comparing a Waveform to a Limit Template . . . . . . . . Figure 3–89: Acquire Menu — Create Limit Test Template . . . . . . . . Figure 3–90: More Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 3–91: Dual Waveform Math Main and Side Menus . . . . . . . . Figure 3–92: System Response to an Impulse . . . . . . . . . . . . . . . . . . . .
Table of Contents List of Tables Table 1–1: Key Features and differences of models . . . . . . . . . . . . . . Table 1–2: Fuse and fuse cap part numbers . . . . . . . . . . . . . . . . . . . . 1–2 1–7 Table 3–1: Autoset defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 3–2: How interleaving affects sample rate . . . . . . . . . . . . . . . . . Table 3–3: Additional resolution bits . . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents viii TDS 500C, TDS 600B, & TDS 700C User Manual
General Safety Summary 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. To Avoid Fire or Personal Injury Use Proper Power Cord. Use only the power cord specified for this product and certified for the country of use. Connect and Disconnect Properly.
General Safety Summary 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. Symbols and Terms 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.
Preface This is the User Manual for the TDS 500C, TDS 600B, & TDS 700C Digitizing Oscilloscopes. The chapter Getting Started briefly describes the TDS Oscilloscope, prepares you to install it, and tells you how to put it into service. The chapter Operating Basics covers basic principles of the operation of the oscilloscope. The operating interface illustrations and the tutorial examples rapidly help you understand how your oscilloscope operates.
Preface Default Model This manual documents the TDS 500C, TDS 600B, & TDS 700C Digitizing Oscilloscopes. Take special note of the following conventions: Some TDS models have two auxiliary channels called AUX 1 and AUX 2, instead of CH 3 and CH 4. References to these channels default to CH 3 and CH 4; if your oscilloscope is one of these models, read AUX 1 and AUX 2 respectively for all references to CH 3 and CH 4 in this manual.
Preface Names also appear in the same case (initial capitals or all uppercase) in the manual as is used on the oscilloscope front panel and menus. Front panel names are all upper case letters, for example, VERTICAL MENU and CH 1. Instruction steps are numbered. The number is omitted if there is only one step.
Preface xiv TDS 500C, TDS 600B, & TDS 700C User Manual
Getting Started
Product Description The Tektronix TDS Oscilloscope is a superb tool for acquiring, displaying, and measuring waveforms.
Product Description Differences by Model Table 1–1 lists some key TDS features and relates them to the different TDS models that this manual covers. Table 1–1: Key Features and differences of models Feature 520C 540C 620B No. of channels 2+21 4 2 + 21 1 GS/s 2 GS/s Digitizing rate, max. No. of Channels. @ maximum rate 1 680B 4 2 + 21 2.
Product Description Product Specification The product specification is found in the technical reference TDS 500C, TDS 600B, & TDS 700C Technical Reference (Performance Verification and Specifications) that is shipped as a standard accessory with the TDS Oscilloscope.
Product Description 1–4 TDS 500C, TDS 600B, & TDS 700C User Manual
Start Up Before you use the TDS Oscilloscope, ensure that it is properly installed and powered on. Preparation 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. Signal Path Compensation Be sure you compensate your oscilloscope for the surrounding temperature.
Start Up CAUTION. Using the P6243 or P6245 Active Probe to measure signals greater than ±40 volts may damage the probe. Input Coupling Be sure to choose the proper input coupling and impedance for the probe or other cabling you use to couple signals to your oscilloscope. You should read Input Impedance Considerations on page 3–7 for information needed to ensure proper coupling of your input signals.
Start Up Power Connector Principal Power Switch 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 Front Cover Removal Power On Fuse Fuse part number Fuse cap part number 0.25 inch × 1.25 inch (UL 198.
Start Up ON/STBY Button 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. Self Test The oscilloscope automatically performs power-up tests each time it is turned on.
Operating Basics
Overview This chapter describes the basic concepts of operating the TDS Oscilloscope. Understanding the basic concepts of your oscilloscope will help you use it much more effectively. The first section, Operating Interface Maps, quickly shows you how the oscilloscope controls are organized and where you can read about them. It also illustrates the general procedures for operating the menu system.
Overview 2–2 TDS 500C, TDS 600B, & TDS 700C User Manual
Operating Interface Maps This section contains illustrations, or maps, of the display, the front and rear panels, and the menu system of the TDS Oscilloscope. These maps will help you understand and operate the oscilloscope. This section also contains a visual guide to using the menu system.
Operating Interface Maps Front Panel Map — Right Side Measurement System, page 3–114 Cursor Measurements, page 3–126 Saving and Recalling Waveforms, page 3–154 File System, page 3–160 Hardcopy, page 3–164 File System, page 3–160 Acquisition Modes, page 3–29 Cursor Measurements, page 3–126 Autoset, page 3–8 InstaVu, page 3–55 (TDS 500C & TDS 700C models only) Help, page 3–181 Status, page 3–179 Saving and Recalling Setups, page 3–151 Color, page 3–44 Display Settings, page 3–38 Remote Communication,
Operating Interface Maps Rear Panel Map Principal Power Switch, page 1–7 Fuse, page 1–6 Centronics Connector Serial Number RS-232 Connector Power Connector, page 1–6 GPIB Connector, page 3–174 Rear Panel Connectors VGA Output Security Bracket SIGNAL OUTPUT – (Provides Analog Signal Output from CH3 – or AX1 – @ 10 mV/div) AUX TRIGGER INPUT – (Provides Auxiliary Trigger Signal Input) MAIN TRIGGER OUTPUT – (Provides Main Trigger (TTL) Output) DELAYED TRIGGER OUTPUT – (Provides Delayed Trigger (TTL)
Operating Interface Maps Display Map The acquisition status, page 3–33 Indicates position of vertical bar cursors in the waveform record, page 3–130 The acquisition record icon Trigger position (T), page 3–71 Shows what part of the waveform record is displayed, page 3–18 The value entered with the general purpose knob or keypad.
Operating Interface Maps To Operate a Menu 1 Press front-panel menu button. (Press SHIFT first if button label is blue.) 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.
Operating Interface Maps To Operate a Pop-Up Menu Press to display pop-up menus. Press it again to make selection. Press here to remove menus from screen. Alternatively, press SHIFT first to make selection in the opposite direction. A pop-up selection changes the other main menu titles.
Tutorial This section quickly makes you acquainted with some of the fundamental operations required to use the TDS Oscilloscope to take measurements. Start this tutorial by doing Setting Up for the Examples on this page. Setting Up for the Examples Perform the following tasks to connect input signals to the TDS Oscilloscope, to reset it, and to become acquainted with its display screen. Once completed, these tasks ready the oscilloscope for use in the examples that follow.
Tutorial Signal Gnd Figure 2–1: Connecting a Probe for the Examples (P6245 shown) Reset the Oscilloscope Do the following steps to reset the oscilloscope to a known factory default state before doing the examples. (You can reset the oscilloscope anytime you begin a new task and need to “start fresh” with known default settings.) 1. Press the save/recall SETUP button to display the Setup menu. (See Figure 2–2.
Tutorial SETUP Button Figure 2–2: SETUP Button Location The oscilloscope displays main menus along the bottom of the screen. Figure 2–3 shows the Setup main menu. OK Confirm Factory Init Menu Item and Button Recall Factory Setup Menu Item and Button Figure 2–3: The Setup Menu 2. Press the button directly below the Recall Factory Setup menu item. 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.
Tutorial 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). Note that a clock icon appears on screen. The oscilloscope displays this icon when performing operations that take longer than several seconds. 4. Press SET LEVEL TO 50% (see Figure 2–4) to be sure the oscilloscope triggers on the input signal.
Tutorial The trigger readout shows that the oscilloscope is triggering on channel 1 (Ch1) on a rising edge, and that the trigger level is about 200–300 mV. The time base readout shows that the main time base is set to a horizontal scale of 500 s/div. The channel readout indicates that channel 1 (Ch1) is displayed with DC coupling. (In AC coupling, ~ appears after the volts/div readout.) The oscilloscope always displays channel 1 at reset.
Tutorial Adjust the Waveform Display The display shows the probe compensation signal. It is a 1 kHz square wave of approximately 0.5 V amplitude. Figure 2–6 shows the main VERTICAL and HORIZONTAL sections of the front panel. Each has SCALE and POSITION knobs. Do the following steps to adjust the size and placement of the waveform using the front-panel knobs: 1. Turn the vertical SCALE knob clockwise. Observe the change in the displayed waveform and the channel readout at the bottom of the display.
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 display and then to autoset the display: 1.
Tutorial AUTOSET Button Figure 2–8: AUTOSET Button Location Figure 2–9 shows the display after pressing AUTOSET. If necessary, you can adjust the waveform now by using the knobs discussed earlier in this example.
Tutorial NOTE. If you are using a passive probe, such as the P6139A probe, the corners on your displayed signal may look rounded or pointed. (See Figure 2–10.) If so, then you may need to compensate your probe. See To Compensate Passive Probes on page 3–6. Figure 2–10: Display Signals Requiring Probe Compensation Example 2: Displaying Multiple Waveforms The TDS Oscilloscope can display up to four channels, three math waveforms, and four reference waveforms at one time.
Tutorial 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. 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 ➞ Recall Factory Setup (main) ➞ OK Confirm Factory Init (side). 3.
Tutorial There are two channel indicators at the left edge of the graticule. Right now, they overlap. 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. 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.
Tutorial Side Menu Title Ch2 Reference Indicator Figure 2–12: The Vertical Main Menu and Coupling Side Menu Assign Controls to Another Channel Pressing a channel (CH) button sets the vertical controls to that channel. It also 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.
Tutorial Side Menu Title Figure 2–13: The Menus After Changing Channels Remove a Waveform Pressing the WAVEFORM OFF button removes the waveform for the currently selected channel. If the waveform you want to remove is not already selected, select that channel using the channel (CH) button. 1. Press WAVEFORM OFF (under the vertical SCALE knob). 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.
Tutorial Example 3: Taking Automated Measurements The TDS Oscilloscope can measure many waveform parameters automatically and read out the results on screen. Do the following tasks to discover how to set up the oscilloscope to measure waveforms automatically. (For information on additional measurement features, see Display Measurement Statistics on page 3–125, Displaying Histograms on page 3–133, and Mask Testing on page 3–136.
Tutorial 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 a measurement on another channel, select that channel, and then select the measurement.) Figure 2–14: Measure Main Menu and Select Measurement Side Menu 8. Press Positive Width (side) ➞ –more– (side) ➞ Rise Time (side) ➞ Positive Duty Cycle (side).
Tutorial Remove Measurement Readouts Use the Measure menu to remove waveforms you no longer want. To remove a measurement individually (you can also remove them, as a group), do the following step: 1. TDS 600B: Press MEASURE ➞ Remove Measrmnt (main) ➞ Measurement 1, Measurement 2, and Measurement 4 (side) to remove those measurements. Leave the rise time measurement displayed. 2.
Tutorial To examine the current values, press Level Setup (main) ➞ 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: 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. The upper right corner of the screen shows the readout High Ref: 90%.
Tutorial General Purpose Knob Setting and Readout General Purpose Knob Icon Highlighted Menu Item with Boxed Readout Value 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 ( ).
Tutorial 1. Press Low Ref (side). 2. On the numeric keypad, press the 2, the 0, and the ENTER ( ) buttons, which sets the low measurement reference to 20%. Observe that the rise-time value has changed. 3. Press Remove Measrmnt (main) ➞ All Measurements (side). That returns the display to its original state. Displaying a Snapshot of Automated Measurements You have seen how to display up to four individual automated measurements on screen.
Tutorial Figure 2–17: Snapshot of Channel 1 Example 4: Saving Setups The TDS Oscilloscope can save its controls settings and recall them later to quickly re-establish a setup. It provides ten storage locations to store up to ten setups. It also provides a file system, so that you can also save setups to a floppy disk. Do the following procedures to learn how to save, and then recall, a setup. NOTE.
Tutorial Save a Setup First, you need to create an instrument setup you want to save. Perform the following steps to create and save a setup that is complex enough that you might prefer not to go through all these steps each time you want that display: 1. If you are not continuing from the previous example, follow the instructions on page 2–9 under the heading Setting Up for the Examples. 2. Press SETUP ➞ Recall Factory Setup (main) ➞ OK Confirm Factory Init (side). 3. Press AUTOSET. 4.
Tutorial Figure 2–18: Save/Recall Setup Menu 8. 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. 9.
Tutorial Recall a Setup To recall the setup, press SAVE/RECALL SETUP ➞ Recall Saved Setup (main) ➞ 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 ➞ Recall Factory Setup (main) ➞ OK Confirm Factory Init (side).
Tutorial 2–32 TDS 500C, TDS 600B, & TDS 700C User Manual
Reference
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 fundamental tasks of acquiring, stably displaying, and taking measurements on waveforms: Acquiring and Displaying Waveforms Triggering on Waveforms 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.
Overview Acquiring and Displaying Waveforms Coupling Waveforms to the Oscilloscope . . . . . . . . . . . . . . . . . . . . . . . . . Setting up Automatically: Autoset and Reset . . . . . . . . . . . . . . . . . . . . . . Selecting Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scaling and Positioning Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Choosing an Acquisition Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overview Determining Status and Accessing Help Displaying Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Displaying the Banner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Displaying Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–179 3–181 3–181 Using Features for Advanced Applications Limit Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overview 3–4 TDS 500C, TDS 600B, & TDS 700C User Manual
Acquiring and Displaying Waveforms To use the TDS Oscilloscope to measure or monitor waveforms, you need to know how to acquire, select, and display those waveforms properly.
Acquiring and Displaying Waveforms The remaining TDS 500C, TDS 600B, and TDS 700C oscilloscopes ship with general-purpose probes — either the P6139A or the P6243, depending on the oscilloscope model. The standard-accessory probes and quantities shipped for these oscilloscopes are listed in Standard Accessories on page A–4. 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.
Acquiring and Displaying Waveforms 5. TDS 500C and 700C models only: Press SHIFT ACQUIRE MENU ➞ Mode (main) ➞ Hi Res (side). 6. TDS 600B models only: Press SHIFT ACQUIRE MENU ➞ Mode (main) ➞ Average (side). Use the keypad to set Averages to 5. 7. Adjust the probe until you see a square wave with a perfectly flat top on the display. Figure 3–2 shows where the adjustment is located.
Acquiring and Displaying Waveforms The oscilloscope switches to 50 W and disables AC coupling (and switches coupling to DC if AC is selected) if you connect an active probe, such as the P6245 probe. Such probes also reduce the maximum volts/div to 10 V as just described. This behavior results in 50 W, nonAC coupling, which is appropriate for such probes (probes with a level 2 interface do not display W in the readout). NOTE.
Acquiring and Displaying Waveforms To Autoset the Oscilloscope 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.
Acquiring and Displaying Waveforms Table 3–1: Autoset defaults (Cont.
Acquiring and Displaying Waveforms To Reset the Oscilloscope Do the following steps to reset the oscilloscope to its factory default settings: 1. Press the Save/Recall SETUP button to display the Setup menu (see Figure 3–3). 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.
Acquiring and Displaying Waveforms Channel Reference Indicator Channel Readout Figure 3–3: The Channel Readout To Select and Remove Waveforms 3–12 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.
Acquiring and Displaying Waveforms 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.
Acquiring and Displaying Waveforms To Find More Information To read about selecting reference waveforms, see Saving and Recalling Waveforms on page 3–154. To read about selecting (and creating) math waveforms, see Waveform Math on page 3–188. Scaling and Positioning Waveforms The TDS Oscilloscope allows you to scale (change the vertical or horizontal size) and position (move up, down, left, or right) waveforms on screen for best display.
Acquiring and Displaying Waveforms Acquisition View Record View Channel Reference Icon Original Position Positioned Vertically Original Scale Scaled Vertically Positioned Horizontally Scaled Horizontally Figure 3–5: Scaling and Positioning To Change Vertical Scale and Position The TDS Oscilloscope permits you to change vertical scale and position quickly from the front panel using dedicated control knobs. To change the vertical scale and position: 1. Turn the vertical SCALE knob.
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.
Acquiring and Displaying Waveforms To Change Vertical Parameters To select the coupling, bandwidth, and offset for the selected waveform, use the Vertical menu (Figure 3–6). This menu also lets you numerically change the position or scale instead of using the vertical knobs. To make such changes, do the following procedures: Coupling.
Acquiring and Displaying Waveforms Fine Scale. To make fine adjustments to the vertical scale, press VERTICAL MENU ➞ 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 ➞ 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. Offset.
Acquiring and Displaying Waveforms Check the Time Base readout at the lower right of the display to see the time/division settings and the time base (main or delayed) being referred to. (See Figure 3–7. Also see Figure 3–5 on page 3–15.) Since all live waveforms use the same time base, the oscilloscope only displays one time base and time/division setting for all the active channels.
Acquiring and Displaying Waveforms 2. If you want the POSITION knob to move faster, press the SHIFT button. When the light above the shift button is on and the display says Coarse Knobs in the upper right corner, the POSITION knob positions waveforms more quickly. Figure 3–8: Horizontal Controls When you select a channel, the horizontal SCALE knob scales all channel waveforms displayed at the same time. If you select a math or reference waveform, the knob scales only the selected waveform.
Acquiring and Displaying Waveforms 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.
Acquiring and Displaying Waveforms 2. To fit an acquired waveform (or with Extended Acquisition On, an acquisition) to the visible screen, regardless of record length, press HORIZONTAL MENU ➞ 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.
Acquiring and Displaying Waveforms NOTE. To function properly, Extended acquisition mode forces some oscilloscope modes and settings to new values. Also, measurements, gating, math, and cursors are restricted to the current waveform record.
Acquiring and Displaying Waveforms Wfm Len displays the length of the waveform record. The settings for Record Length in the Horizontal menu and for Extended Acquisition mode (on or off) determine the length. Acq Duration displays the time spanned by the acquisition data. Waveform Record Start displays/selects the percentage of the acquisition data that is before the waveform record of the selected channel and any locked live channels.
Acquiring and Displaying Waveforms 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 2–17. To learn how to use delay with waveforms, see Delayed Triggering on page 3–106. To learn how to magnify waveforms, see Zooming on Waveforms, on page 3–49.
Acquiring and Displaying Waveforms The oscilloscope uses the samples it takes (see Figure 3–13) 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 3–12).
Acquiring and Displaying Waveforms Equivalent-Time Sampling A TDS 500C or TDS 700C model oscilloscope (the TDS 600B models use only real time sampling) uses equivalent time sampling to extend its sample rate over its real-time maximum sampling rate, but only under two conditions: You must have turned equivalent-time on in the Acquisition menu.
Acquiring and Displaying Waveforms Interpolation Your oscilloscope can interpolate between the samples it acquires. Like for equivalent time sampling, it does so only when it cannot obtain all the real samples it needs to fill up its waveform record. For instance, setting the horizontal SCALE to progressively faster acquisition rates leaves progressively shorter time periods for the waveform record.
Acquiring and Displaying Waveforms Interleaving A TDS 500C or TDS 700C Oscilloscope can interleave its channels to attain higher digitizing rates without equivalent time sampling or interpolating. The oscilloscope applies the digitizing resources of unused channels (that is, channels that are turned off) to sample those that are in use (turned on). Table 3–2 lists how interleaving more than one digitizer to sample a channel extends the maximum digitizing rate.
Acquiring and Displaying Waveforms Figure 3–15 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.
Acquiring and Displaying Waveforms Single Waveform Acquisition Samples Acquired in Four Acquisition Intervals Interval 1 2 3 Acquisition Mode 4 Displayed Record Points Interval 1 2 3 Waveform Drawn on CRT 4 Sample Uses first sample in interval Use for fastest acquisition rate. This is the default mode. Peak Detect Uses highest and lowest samples in two intervals Use to reveal aliasing and for glitch detection. Provides the benefits of enveloping with the speed of a single acquisition.
Acquiring and Displaying Waveforms Hi Res Mode. TDS 500C and 700C models only: Hi Res mode averages all samples taken during an acquisition interval to create a record point. The average results in a higher-resolution, lower-bandwidth waveform. A key advantage of Hi Res is its potential for increasing resolution regardless of the input signal. Table 3–3 and the equations shown below illustrate how you can obtain up to 15 significant bits with Hi res mode.
Acquiring and Displaying Waveforms Checking the Acquisition Readout 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 3–16.) The state “Run:” shows the sample rate and acquisition mode. The state “Stop:”shows the number of acquisitions acquired since the last stop or major change.
Acquiring and Displaying Waveforms NOTE. TDS 500C and 700C models only: Selecting Hi Res mode in the Acquire menu automatically reduces long record-length settings to prevent overflow of acquisition memory. Because Hi Res mode uses twice the acquisition memory used by other acquisition modes, allowing selection of the longer horizontal record lengths with Hi Res mode would cause the oscilloscope to run out of memory.
Acquiring and Displaying Waveforms Check Table 3–4 below to determine the time base setting(s) at which the switch from real-time sampling (RT) to equivalent time sampling or interpolation (ETI) occurs for your model.
Acquiring and Displaying Waveforms Figure 3–17: Acquire Menu — Stop After 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 oscilloscope will resume taking acquisitions. Press Single Acquisition Sequence (side).
Acquiring and Displaying Waveforms 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.
Acquiring and Displaying Waveforms Methods to Check and Eliminate. To quickly check for aliasing, slowly increase the horizontal scale (time per division setting). If the shape of the displayed waveform changes drastically or becomes stable at a faster time base setting, your waveform was probably aliased. To avoid aliasing, be sure to sample the input signal at a rate more than twice as fast as the highest frequency component.
Acquiring and Displaying Waveforms Change Display Settings To bring up the Display menu: Press DISPLAY ➞ Settings (main) ➞ 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 3–44.
Acquiring and Displaying Waveforms Figure 3–19: Display Menu — Style NOTE. TDS 500C and TDS 700C models only: See Using InstaVu Acquisition Mode, on page 3–55, to see how Style setup differs for InstaVu mode. Adjust Intensity Intensity lets you set text/graticule and waveform intensity (brightness) levels. To set the intensity: Press DISPLAY ➞ Intensity (main) ➞ Text/Grat or Waveform (side). Enter the intensity percentage values with the keypad or the general purpose knob.
Acquiring and Displaying Waveforms 1. TDS 600B: Press DISPLAY ➞ Readout Options (main). TDS 500C and TDS 700C Models: Press DISPLAY ➞ Mode (main) ➞ Normal (pop-up) ➞ Format/RO (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.
Acquiring and Displaying Waveforms 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 3–168.) 4. Press Display Date/Time (side) to turn it on or off. Push Clear Menu to see the current date and time. Select Interpolation Filter The display filter types are sin(x)/x interpolation and linear interpolation.
Acquiring and Displaying Waveforms NOTE. Selecting either NTSC or PAL graticules automatically changes the vertical scale, position settings, coupling, and sets to zero any vertical offset of any channel displayed. These settings are not restored after switching to other graticule types. Therefore, you might want to recall the factory setup or other stored setup after selecting a different graticule. Select the Format The oscilloscope displays waveforms in either of two formats: YT and XY.
Acquiring and Displaying Waveforms 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.
Acquiring and Displaying Waveforms Figure 3–21: Display Menu — Setting Choose a Palette 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. If you are using a persistence display and want to vary the color of each point depending on its persistence, choose Persistence Palettes.
Acquiring and Displaying Waveforms NOTE. Use at higher room temperatures or with higher intensity display formats, such as the white fields in the Hardcopy Preview palette, can temporarily degrade display quality. You can select the Hardcopy Preview palette when using certain color hardcopy formats. The default colors in the this palette comprise a white background and fully saturated primary colors which generally produce the best result.
Acquiring and Displaying Waveforms ScrTxt Figure 3–22: Display Menu — Palette Colors Set Math Waveform Color To define math waveform colors: 1. Choose to define math waveform colors by selecting the main menu Map Math item. 2. Select one of the three math waveforms by pressing Math in the side menu. 3. If you want to assign the selected math waveform to a specific color, press Color and cycle through the choices. 4.
Acquiring and Displaying Waveforms 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.
Acquiring and Displaying Waveforms 2. Select the object(s) you want to restore by pressing Reset Current Palette To Factory, Reset All Palettes To Factory or Reset All Mappings To Factory in the side menu. Figure 3–24: Display Menu — Restore Colors Zooming on Waveforms The TDS Oscilloscope can expand or compress (zoom in or out) on a waveform without changing the acquisition parameters (sample rate, record length, and so on).
Acquiring and Displaying Waveforms Using with Waveforms To help you use zoom effectively, consider how it operates on waveforms. When zooming vertically, the oscilloscope expands or contracts the selected waveform only. Also, the oscilloscope only positions the selected waveform when in Zoom. When zooming horizontally, Zoom expands either the selected waveform, all live waveforms, or all live and reference waveforms, depending on the setting for Horizontal Lock in the Zoom menu.
Acquiring and Displaying Waveforms Zoom a Waveform 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 ➞ Mode (main) ➞ ON (side). The ZOOM front-panel button should light up. Toggle Dual Zoom to OFF in the side menu. 3.
Acquiring and Displaying Waveforms Only the selected waveform (the top one) changes size. Figure 3–25: Zoom Mode with Horizontal Lock Set to None Set Interpolation Reset Zoom To change the interpolation method used, press DISPLAY ➞ Settings (main) ➞ Display (pop-up) ➞ Filter (main) ➞ Sin(x)/x Interpolation or Linear Interpolation (side). To reset all zoom factors to their defaults, do the following step: Press ZOOM ➞ Reset (main) ➞ Reset Live Factors or Reset All Factors (side).
Acquiring and Displaying Waveforms 2. To scale or position the unmagnified waveform, press Selected Graticule (main) ➞ Lower (side). Use the vertical and horizontal knobs to scale and position the unmagnified waveform in the box. Note that as you scale or move the unmagnified waveform relative to the box, the oscilloscope alters the magnified display accordingly to include only the waveform portion within the box. 3.
Acquiring and Displaying Waveforms Dual Zoom a Waveform To select Dual Zoom, press ZOOM ➞ Mode (main) ➞ Dual Zoom (side) to toggle it to ON. (See Figure 3–27.) 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.
Acquiring and Displaying Waveforms Selected Graticule Zoomed Waveform Edges Zoom Boxes Unzoomed Waveform Figure 3–27: Dual Zoom — Shown Dual Window (Preview) Mode Using InstaVu Acquisition Mode The TDS 500C and 700C Oscilloscopes can use InstaVu acquisition mode to reduce the dead time between waveform updates that normally occur when digitizing storage oscilloscopes (DSOs) acquire waveforms.
Acquiring and Displaying Waveforms InstaVu mode increases the waveform capture rate to up to 400,000 waveforms per second (maximum waveform rate depends on oscilloscope model), updating the waveform array many times between displays. This very fast frame rate greatly increases the probability that runts, glitches, and other short term changes will accumulate in waveform memory. The oscilloscope then displays the waveform at the normal display rate using variable or infinite persistence.
Acquiring and Displaying Waveforms Normal DSO Mode 1st Acquired Waveform Record Next Acquired Waveform Record Dead Time Next Acquired Waveform Record Dead Time Dead Time Waveform Memory Waveform Memory Waveform Memory Display Updated Display Updated Display InstaVu Mode 1st Set of Acquired Waveform Records Next Set of Acquired Waveform Records Next Set of Acquired Waveform Records Waveform Memory Bit Map Waveform Memory Bit Map Waveform Memory Bit Map Variable Persistence Display Updated
Acquiring and Displaying Waveforms To Set the InstaVu Style To change the InstaVu display style, do the following steps: 1. Press DISPLAY ➞ Mode (main) ➞ InstaVu (pop-up) ➞ Style (main). 2. Select between Vectors and Dots in the side menu. (Dots display is the factory default setting.) 3. Select between Infinite Persistence and Variable Persistence in the side menu. (Variable Persistence is the factory default setting.) 4.
Acquiring and Displaying Waveforms If you select any of these modes before or while InstaVu is on, they will remain selected in their respective menus, but the oscilloscope will ignore them. It will put the modes into effect when you turn InstaVu off. If the oscilloscope setup is not as you expect when you turn InstaVu off, this may be because the oscilloscope quit ignoring these InstaVu incompatible modes. InstaVu mode disallows selection of Math waveforms.
Acquiring and Displaying Waveforms If you are using the FastFrame mode, you can jump to the desired frame. To use FastFrame, do the following steps: 1. Press HORIZONTAL MENU ➞ FastFrame Setup (main) ➞ FastFrame (side) to toggle on or off the use of FastFrame (see Figure 3–31). Figure 3–31: Horizontal Menu — FastFrame Setup 2. Press Frame Length or Frame Count (side) and use the general purpose knob to enter FastFrame parameters.
Acquiring and Displaying Waveforms If you shift the waveform right or left with the front-panel HORIZONTAL POSITION knob, the window next to the side-menu Frame button will indicate the frame number of the waveform at the center of the screen. FastFrame Operating Characteristics. Consider the following operating characteristics when using FastFrame: Envelope, Average, and Hi Res form the envelope or average following the last frame of the concatenated record.
Acquiring and Displaying Waveforms 3–62 TDS 500C, TDS 600B, & TDS 700C User Manual
Triggering on Waveforms To use the TDS Oscilloscope to measure or monitor waveforms, you need to know how to trigger a stable display of those waveforms.
Triggering on Waveforms Triggered Waveform Untriggered Waveforms Figure 3–32: Triggered Versus Untriggered Displays The Trigger Event Trigger Sources 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.
Triggering on Waveforms Trigger Types 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 3–72. A brief definition of each type follows: Edge is the “basic” trigger. You can use it with both analog and digital test circuits.
Triggering on Waveforms 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.
Triggering on Waveforms Acquisition Interval Acquisition Interval Trigger Level Indicates Trigger Points Holdoff Holdoff Holdoff Triggers are not recognized during holdoff time. Figure 3–33: Trigger Holdoff Time Ensures Valid Triggering Trigger Coupling Trigger Position Trigger coupling determines what part of the signal is passed to the trigger circuit.
Triggering on Waveforms Slope and Level The slope control determines whether the oscilloscope finds the trigger point on the rising or the falling edge of a signal. (See Figure 3–34.) 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 3–34.
Triggering on Waveforms Trigger Status Lights Figure 3–35: TRIGGER Controls and Status Lights To Set to 50% 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.
Triggering on Waveforms To Single Trigger To trigger on the next valid trigger event and then stop, press SHIFT FORCE TRIG. Now press the RUN/STOP button each time you want to initiate the single sequence of acquisitions. To leave Single Trig mode, press SHIFT ACQUIRE MENU ➞ Stop After (main) ➞ RUN/STOP Button Only (side). See the description under Stop After on page 3–35 for further discussion of single sequence acquisitions.
Triggering on Waveforms Trigger Readout. To quickly determine the settings of some key trigger parameters, check the Trigger readout at the bottom of the display. (See Figure 3–36.) The readouts differ for edge, logic, and pulse triggers. Main Time Base Time/Div Main Time Base Main Trigger Source = Ch 1 Main Trigger Slope = Rising Edge Main Trigger Level Figure 3–36: Example Trigger Readouts — Edge Trigger Selected Record View.
Triggering on Waveforms Trigger Position Relative to the Display and Waveform Record Trigger Point Indicator Indicating the Trigger Position on the Waveform Record Trigger Bar Indicating the Trigger Level on the Waveform Record Figure 3–37: Record View, Trigger Position, and Trigger Level Bar Readouts Trigger Menu Each trigger type (edge, logic, and pulse) has its own main trigger menu, which is described as each type is discussed in this section.
Triggering on Waveforms Main Time Base Time/Div Main Trigger Source = Ch 1 Main Time Base Main Trigger Slope = Rising Edge Main Trigger Level Figure 3–38: Edge Trigger Readouts To Select Edge Triggering Use the edge trigger menu to select edge triggering and to perform the procedures for source, coupling, slope, trigger level, mode, and holdoff that follow. To bring up the Edge Trigger menu, press TRIGGER MENU ➞ Type (main) ➞ Edge (pop-up). (See Figure 3–39.
Triggering on Waveforms To Select a Source To select which source you want for the trigger: Press TRIGGER MENU ➞ Type (main) ➞ Edge (pop-up) ➞ Source (main) ➞ Ch1, Ch2, Ch3, Ch4, AC Line, or DC Aux (side). To Specify Coupling To select the coupling you want, press TRIGGER MENU ➞ Type (main) ➞ Edge (pop-up) ➞ Coupling (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.
Triggering on Waveforms To Set Mode & Holdoff You can change the holdoff time and select the trigger mode using this menu item. See Trigger Modes and Trigger Holdoff beginning on page 3–65 for a description of these features. To set mode and holdoff, do the following steps: 1. Press the TRIGGER MENU ➞ Mode & Holdoff (main) ➞ Auto or Normal (side). The modes operate as follows: In Auto mode the oscilloscope acquires a waveform after a specific time has elapsed even if a trigger does not occur.
Triggering on Waveforms 2. Select the rising or falling edge from the side menu. To Set Level Press the TRIGGER MENU ➞ Type (main) ➞ Edge (pop-up) ➞ Level (main) ➞ Level, Set to TTL, Set to ECL, or Set to 50% (side). Level lets you enter the trigger level using the general purpose knob or the keypad. Set to TTL fixes the trigger level at +1.4 V. Set to ECL fixes the trigger level at –1.3 V. NOTE.
Triggering on Waveforms The Boolean logic function — select from AND, NAND, OR, and NOR 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.
Triggering on Waveforms 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 3–6 are met.
Triggering on Waveforms 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.
Triggering on Waveforms TS = Setup Time TH = Hold Time Setup/Hold Violation Zone = TS + TH TS + TH must be +2 ns Setup/Hold Violation Zone +TS +TH Clock Level Clock Signal Setup/Hold Violation Zone –TS +TH Clock Level Clock Signal Setup/Hold Violation Zone –TH +TS Clock Level Clock Signal Positive TS; Negative TH Negative TS; Positive TH Figure 3–40: Violation Zones for Setup/Hold Triggering 3–80 TDS 500C, TDS 600B, & TDS 700C User Manual
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 Figure 3–41: 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.
Triggering on Waveforms Figure 3–42: Logic Trigger Menu To Define Pattern Inputs. To set the logic state for each of the input channels (Ch1, Ch2, ...): 1. Press TRIGGER MENU ➞ Type (main) ➞ Logic (pop-up) ➞ Class (main) ➞ Pattern (pop-up) ➞ Define Inputs (main) ➞ 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 3–42). To Set Thresholds. To set the logic threshold for each channel: 1.
Triggering on Waveforms To Define the Logic. To choose the logic function you want applied to the input channels (see page 3–77 for definitions of the logic functions for both pattern and state triggers): Press TRIGGER MENU ➞ Type (main) ➞ Logic (pop-up) ➞ Class (main) ➞ Pattern (pop-up) ➞ Define Logic (main) ➞ AND, OR, NAND, or NOR (side). Set Trigger When.
Triggering on Waveforms Note the position of the trigger indicator in Figure 3–43. 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: It waits for the logic condition to become TRUE. It starts timing and waits for the logic function to become FALSE.
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 3–76 through 3–78 describe how state triggers work). To use state triggering, do the following procedures. Select State Triggering. Press TRIGGER MENU ➞ Type (main) ➞ Logic (pop-up) ➞ Class (main) ➞ State (pop-up). Define Inputs. To set the logic state for each of the input channels (Ch1, Ch2, ...): 1.
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 & Holdoff on page 3–75. To learn more about trigger mode and holdoff, see the descriptions Trigger Modes and Trigger Holdoff on page 3–65.
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 ➞ Type (main) ➞ Logic (pop-up) ➞ Class (main) ➞ Setup/Hold (pop-up) ➞ Levels (main) ➞ Clock Level or Data Level (side). 2. Turn the general purpose knob or use the keypad to set values for the clock level and for the data level you select.
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. Figure 3–44: Triggering on a Setup/Hold Time Violation In most cases, you will enter positive values for both setup and hold time.
Triggering on Waveforms Triggering on Pulses The TDS Oscilloscope 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.
Triggering on Waveforms Trigger Class = Runt Figure 3–45: Pulse Trigger Readouts Table 3–7: Pulse trigger definitions Name 3–90 Definition Glitch positive Triggering occurs if the oscilloscope detects positive spike widths less than the specified glitch time. Glitch negative Triggering occurs if the oscilloscope detects negative spike widths less than the specified glitch time.
Triggering on Waveforms Table 3–7: Pulse trigger definitions (cont.) Name To Trigger on a Glitch 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.
Triggering on Waveforms Figure 3–46: Main Trigger Menu — Glitch Class Select the Source. To specify which channel becomes the pulse trigger source: Press TRIGGER MENU ➞ Type (main) ➞ Pulse (pop-up) ➞ Source (main) ➞ Ch1, Ch2, Ch3, or Ch4 (side). The source selected becomes the trigger source for all four trigger classes. Select the Polarity & Width. To specify polarity (positive, negative, or either) and width of the glitch, do the following steps: 1.
Triggering on Waveforms Set to Accept or Reject Glitch. To specify whether to trigger on glitches or ignore glitches, press TRIGGER MENU ➞ Type (main) ➞ Pulse (pop-up) ➞ Class (main) ➞ Glitch (pop-up) ➞ 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.
Triggering on Waveforms Select the Source. To specify which channel becomes the pulse trigger source: Press TRIGGER MENU ➞ Type (main) ➞ Pulse (pop-up) ➞ 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 ➞ Type (main) ➞ Pulse (pop-up) ➞ Class (main) ➞ Runt (pop-up) ➞ Polarity (main) ➞ Positive, Negative, or Either (side).
Triggering on Waveforms Selected trigger bar at upper threshold. Unselected trigger bar at lower threshold. Runt Pulse Crosses First Threshold Only, Recrosses First Threshold Level, and Triggers Acquisition Figure 3–47: Main Trigger Menu — Runt Class Note the position of the trigger indicator in Figure 3–47. Triggering occurs at the point the pulse returns over the first (lower) threshold going negative without crossing the second threshold level (upper).
Triggering on Waveforms 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 & Holdoff on page 3–75. To learn more about trigger mode and holdoff, see Trigger Modes and Trigger Holdoff on page 3–65. Trigger Based on Pulse Width When you select the pulse class Width, the oscilloscope will trigger on a pulse narrower (or wider) than some specified range of time (defined by the upper limit and lower limit).
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 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 .
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.
Triggering on Waveforms 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 ➞ Type (main) ➞ Pulse (pop-up) ➞ Class (main) ➞ Slew Rate (pop-up) ➞ Trigger When (main) ➞ Trigger if Faster Than or Trigger if Slower Than (side). (See Figure 3–48.) NOTE.
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 Figure 3–48: Main Trigger Menu — Slew Rate Class 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).
Triggering on Waveforms The Trigger When side menu indicates the oscilloscope will trigger on pulses with slew rates slower than the slew rate setting. Since the pulse edge slews at 20 mV/ns, which is faster than the slew rate setting of 16 mV/ns, the oscilloscope triggers. The trigger point indicator shows where the oscilloscope triggers.
Triggering on Waveforms 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 ➞ Type (main) ➞ Pulse (pop-up) ➞ Class (main) ➞ Timeout (pop-up) ➞ Time (main) 2. Turn the general purpose knob or use the keypad to set values for the timeout time. Set the Level .
Triggering on Waveforms Communications Triggering The TDS Oscilloscope can trigger on communication signals (option 2C only). Table 3–8 lists the available standards, codes, and bit rates. This section describes how to use Comm triggering — how to select the Source, Code, bit rate, telecom Standard, Pulse Form, Level or Threshold, and Mode and Holdoff. NOTE. To function properly, Comm triggers force some oscilloscope modes and settings to new values.
Triggering on Waveforms Table 3–8: Comm triggers (cont.) To Select Comm Triggering Standard Name Code1 Bit Rate STS-1 AMI 51.84 Mb/s STS-3 CMI 155.52 Mb/s FC133 NRZ 132.8 Mb/s FC266 NRZ 265.6 Mb/s FC531 NRZ 531.2 Mb/s FC1063 NRZ 1.0625 Mb/s D2 NRZ 143.18 Mb/s D1 NRZ 270 Mb/s FDDI NRZ 125 Mb/s 1 AMI = Alternate Mark Inversion. CMI = Code Mark Inversion. NRZ = Non-return to Zero 2 These Telecom DS0 standards are automatically selected from the Mask Menu.
Triggering on Waveforms Figure 3–49: Main Trigger Menu — Comm Type To Select a Communications Standard To select the standard and bit rate of the communication signal that triggering will occur on: 1. Press TRIGGER MENU ➞ Type (main) ➞ Comm (pop-up) ➞ Standard (main). 2. Select an standard from the side menu. Only standards for the selected Code are displayed. See Table 3–8 on page 3–103 for a list of the available standards and their bit rates.
Triggering on Waveforms Table 3–9: Communications pulse forms To Set Level or Threshold AMI CMI NRZ Isolated +1 Plus One Eye Diagram Isolated –1 Minus One Rise Eye Diagram Zero Fall Eye Diagram Pattern 0-7 Press the TRIGGER MENU ➞ Type (main) ➞ Comm (pop-up) ➞ Level or Threshold (main) ➞ High, Low, Level, Set to TTL, Set to ECL, or Set to 50% (side).Only selections for the selected Code are displayed. High lets you enter the high threshold using the general purpose knob or the keypad.
Triggering on 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 3–50.
Triggering on Waveforms NOTE. Due to hardware limitations, the delayed time base cannot be made triggerable when the main trigger type is Logic, any class, or when the main trigger type is Pulse with Runt or Slew Rate classes selected. For these settings, the oscilloscope will force the delayed time base to be in Runs After mode. To Run After Delay You use the Horizontal menu to select and define either delayed runs after main or delayed triggerable.
Triggering on Waveforms Posttrigger Record Pretrigger Record Delayed Runs After Main Delayed Trigger Waveform Record Main Trigger Point Main Trigger Source Time Delay (From Horiz Menu) Start Posttrigger Acquisition Delayed Triggerable By Events Delayed Trigger Waveform Record Main Trigger Point Main Trigger Source Delayed Trigger Source Waiting for nth Event (Where n=5) Start Posttrigger Acquisition (Trigger on nth Delayed Trigger Event) Delayed Triggerable By Time Delayed Trigger Waveform Record
Triggering on Waveforms 4. If Type is set to Pulse, press Class (main) and change it to either Glitch or Width as fits your application. Runt and Slew Rate pulse classes are incompatible with Delayed Triggerable. 5. Press HORIZONTAL MENU ➞ Time Base (main) ➞ Delayed Only (side) ➞ 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.
Triggering on Waveforms Figure 3–53: 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) ➞ Main Trigger, DC, or Noise Rej (side) to define how the input signal will be coupled to the delayed trigger.
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 trigger level to 50% of the peak-to-peak value of the delayed trigger source signal. NOTE.
Measuring Waveforms To make the best use of the TDS Oscilloscope when taking measurements, you need to know how to use the five types, or classes, of measurements it can take.
Measuring Waveforms Taking Automated Measurements The TDS Oscilloscope 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.
Measuring Waveforms Table 3–10: Measurement definitions (cont.) Name Definition Cycle RMS 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 MidRef crossings of two different traces or the gated region of the traces. Fall Time Timing measurement.
Measuring Waveforms Table 3–10: Measurement definitions (cont.) Name Definition Phase Timing measurement. The amount one waveform leads or lags another in time. Expressed in degrees, where 360 comprise one waveform cycle. Period Timing measurement. Time it takes for the first complete signal cycle to happen in the waveform or gated region. The reciprocal of frequency. Measured in seconds. Positive Duty Cycle Timing measurement of the first cycle in the waveform or gated region.
Measuring Waveforms Measurement Readout Area Figure 3–55: 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 3–56): 1. TDS 600B: Press MEASURE ➞ Select Measrmnt (main). 2. TDS 500C and TDS 700C: Press MEASURE ➞ Measure (pop-up) ➞ Select Measrmnt (main). 3.
Measuring Waveforms Figure 3–56: Measure Menu Remove Measurements Be careful 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. TDS 600B: Press MEASURE ➞ Remove Measrmnt (main). 2.
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. TDS 600B: Press MEASURE ➞ Gating (main) ➞ Gate with V Bar Cursors (side). (See Figure 3–57.) 2. TDS 500C and TDS 700C: Press MEASURE ➞ Measure (pop-up) ➞ Gating (main) ➞ Gate with V Bar Cursors (side). (See Figure 3–57.
Measuring Waveforms 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.
Measuring Waveforms 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 3–58. 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.
Measuring Waveforms Take a Delay Measurement 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. TDS 600B: Press MEASURE ➞ Select Measrmnt (main) ➞ Delay (side) ➞ Delay To (main) ➞ Measure Delay to. 2. TDS 500C and TDS 700C: Press MEASURE ➞ Measure (pop-up) ➞ Select Measrmnt (main) ➞ Delay (side) ➞ Delay To (main) ➞ Measure Delay to. 3.
Measuring Waveforms 4. TDS 600B: Press MEASURE ➞ Select Measrmnt (main) ➞ Delay (side) ➞ Edges (main). 5. TDS 500C and TDS 700C: Press MEASURE ➞ Measure (pop-up) ➞ Select Measrmnt (main) ➞ Delay (side) ➞ 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: The selection you choose defines which edges you want the delayed measurement to be made between.
Measuring Waveforms To use Snapshot, obtain a stable display of the waveform to be measured (pressing AUTOSET may help). Then do the following steps: 1. TDS 600B: Press MEASURE ➞ SNAPSHOT (main). 2. TDS 500C and TDS 700C: Press MEASURE ➞ Measure (pop-up) ➞ SNAPSHOT (main). 3. 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. 4. Push Remove Measrmnt.
Measuring Waveforms Consider the following rules when taking a snapshot: Display Measurement Statistics (TDS 500C and TDS 700C Only) Be sure to display the waveform properly before taking a snapshot. Snapshot does not warn you if a waveform is improperly scaled (clipped, low signal amplitude, low resolution, etc.). To vary the source for taking a snapshot, simply select another channel, math, or ref memory waveform and then execute snapshot again.
Measuring Waveforms To display measurement statistics, obtain a stable display of the waveform to be measured. Then do the following steps: 1. Press MEASURE ➞ Measure (pop-up) ➞ Statistics (main) ➞ Statistics Min/Max or Statistics Mean/StdDev (side). Statistics Min/Max — Displays the minimum and maximum statistics for measurements. Statistics Mean/StdDev — Displays the mean and standard deviation statistics for measurements. 2.
Measuring Waveforms Cursor Types Horizontal Bar Cursors There are three cursor types: horizontal bar, vertical bar, and paired (see Figure 3–61). Vertical Bar Cursors Paired Cursors Figure 3–61: 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 3–61.
Measuring Waveforms In tracking mode, you normally move both cursors in tandem using the general purpose knob. The two cursors remain a fixed distance (time or voltage) from each other. Press SELECT to temporarily suspend cursor tracking. You can then use the general purpose knob to adjust the distance of the solid cursor relative to the dashed cursor. A second push toggles the cursors back to tracking.
Measuring Waveforms Paired. The value after one D shows the voltage difference between the two Xs; the other D 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 3–64.) TDS 500C and TDS 700C Models Only: In FastFrame mode, the D shows the time difference between the two cursors only if both cursors are in the same frame.
Measuring Waveforms Position of Vertical Bar Cursors (Useful for Locating Cursors Outside the Display) Cursor Readout (Paired) Non-selected Cursor (Dashed Vertical Bar) Selected Cursor (Solid Vertical Bar) Figure 3–64: Paired Cursor Menu and Readouts Set Mode and Adjust the Cursors To select the cursor mode and adjust the cursors in either mode, do the following steps: 1.
Measuring Waveforms 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. Select Cursor Speed To change the cursors speed, press SHIFT before turning the general purpose knob.
Measuring Waveforms To find information on cursor units with video waveforms, see the TDS Family Option 05 Video Trigger Interface, if your oscilloscope is equipped with the video trigger option. Taking Graticule Measurements The TDS Oscilloscope provides a graticule for measuring the difference (either in time or amplitude) between two points on a waveform record. Graticule measurements provide you with quick, visual estimates.
Measuring Waveforms Measure Waveform Time 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 S/division, then you can easily calculate the waveform period as: 5 divisions × 50 S/division = 250 s, or 4 kHz.
Measuring Waveforms Reset Histogram Counting Display a Histogram 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. 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.
Measuring Waveforms Histogram Measurement List The TDS Oscilloscope provides you with 10 histogram measurements. Table 3–11 lists brief definitions of the measurements. Table 3–11: Measurement definitions Name Definition Mean The average of all acquired points within (or on) the histogram box. Median Half of all acquired points within (or on) the histogram box are less than and half are greater than this value.
Measuring Waveforms 2. Press MEASURE ➞ Histogram (pop-up) ➞ Histogram Measrmnt (main). 3. Select a measurement from the side menu (see Table 3–11 on page 3–135). Remove Measurements The Remove Measrmnt selection provides the same functions as in the Measure menu. See Remove Measurements on page 3–118. Mask Testing (Option 2C Only) The digitizing oscilloscope can perform mask testing. You can select a standard mask or create and select a user mask. NOTE.
Measuring Waveforms Figure 3–66: Mask menu NOTE. If you select Manual, some controls are automatically adjusted; if you select Auto, a complete Autoset is performed. To control whether an autoset is performed when a standard mask is selected, press MEASURE ➞ Measure (main) ➞ Masks (pop-up) ➞ Mask Options (main). Then toggle Std Mask Autoset (side) to Auto or Manual. NOTE. If you select OFF, offset is not adjusted when the DS–0, E1, E2, E3, or T1.102 standards are selected.
Measuring Waveforms To enable the optical reference receiver (option 3C and 4C) required by some optical standards that require a Bessel–Thompson response, press MEASURE ➞ Measure (main) ➞ Masks (pop-up) ➞ Mask Options (main). Then toggle Filter (side) to Enable. To determine the calibration status of the communication filter, press SHIFT ➞ UTILITY ➞ System (main) ➞ Cal (pop-up). Then read the calibration status from the Comm Filter menu.
Measuring Waveforms 3. You create or edit a mask by moving a cross-hair cursor on the display and adding or deleting points as required. To move the cursor, turn the general purpose knob. To change the cursor direction, press SELECT. 4. To add a point to the mask, move the cursor to the location and press Add Point (side). 5. To delete a point from the mask, move the cursor to the point and press Delete Point (side). 6. To delete all points from the mask, press Delete All Points (side). 7.
Measuring Waveforms These points form the top of the mask Top/bottom dividing line (not displayed) Left-most point Right-most point These points form the bottom of the mask Figure 3–67: Creating a User Mask 3–140 To create a mask with a concave side, create several masks to cover the same area. Masks are saved with setups, so you can save sets of masks by defining them, and then storing the instrument setup.
Measuring Waveforms Table 3–12: Standard masks SONET SDH ITU-T T1.102 Fibre channel Video Miscellaneous None None None None None None OC1/STM0 51.84 Mb/s DS–0 Sgl Single 64.4 kb/s DS1 1.544 Mb/s FC133 Optical 132.8 Mb/s 4fsc NTSC FDDI Halt 125 Mb/s “D2” 143.18 Mb/s OC3/STM1 155.52 Mb/s DS-0 Dbl Double 64 kb/s DS1A 2.048 Mb/s FC266 Optical 265.6 Mb/s 4:2:2 “D1” 270 Mb/s OC12/STM4 622.08 Mb/s DS-0 Data Data Contra 64 kb/s DS1C 3.152 Mb/s FC531 Optical 531.
Measuring Waveforms Signal Path Compensation The TDS Oscilloscope lets you compensate the internal signal path used to acquire the waveforms you measure. SPC optimizes the oscilloscope capability to make accurate measurements based on the ambient temperature. Run an SPC anytime you wish to ensure that the measurements you make are made with the most accuracy possible. You should also run an SPC if the temperature has changed more than 5 C since the last SPC was performed. NOTE.
Measuring Waveforms Figure 3–68: Performing a Signal Path Compensation Channel/Probe Deskew 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.
Measuring Waveforms 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. 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.
Measuring Waveforms 2. Power on the digitizing oscilloscope and allow a 20 minute warm-up before doing this procedure. 3. Press SHIFT UTILITY ➞ System (main) ➞ 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 3–142), and then continue with this procedure. 5. Press the front-panel button corresponding to the input channel on which you installed the probe. 6.
Measuring Waveforms Figure 3–69: Probe Cal Menu and Gain Compensation Display 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 10). If gain compensation did not complete successfully, you may get the message “Compensation Error.
Measuring Waveforms 15. Note the compensation error amount. Skip to step 20. 16. Disconnect the probe from any signal you may have connected it to. Leave the probe installed on its channel. 17. Press OK Compensate Offset (side). 18. Wait for offset compensation to complete (one to three minutes). When offset compensation completes, the following occurs: The clock icon will disappear. If offset compensation did not complete successfully, you may get the message “Compensation Error.
Measuring Waveforms 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.
Measuring Waveforms Figure 3–70: Re-use Probe Calibration Data Menu NOTE. If the Re-use Probe Calibration data menu is displayed, do not select OK Use Existing Data if the probe currently installed is not of the same impedance stored for the Probe Cal. For example, if the last Probe Cal stored for a channel was done with a passive 50 probe installed, do not install a passive 1 M probe and select OK Use Existing Data if the menu appears.
Measuring Waveforms Table 3–13: Probe cal status Type probe connected2 Probe be Cal’d? al 1 U e action User a i Simple interface3 TEKPROBE interface4 No Doesn’t Matter Initialized Initialized Yes Power off Initialized (probe data is retained) Initialized (probe data is retained) Yes Power on Can not detect different probe: Display Re-use Probe Calibration Data menu Cal’d Probe: Pass Different probe: Initialized Different probe: Initialized Yes Disconnect Probe Initialized Initializ
Saving Waveforms and Setups The TDS Oscilloscope can save and recall the waveforms you measure and the setups you use to measure them. It can also output or save a copy of its display screen.
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.
Saving Waveforms and Setups NOTE. Upon power on, the oscilloscope creates the “wild card” file, marked in the file utilities menu by the name TEK?????.SET and by a wild card icon as shown 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 TEK00001.SET, the second in TEK00002.SET, and so on.
Saving Waveforms and Setups Executing Tek Secure accomplishes the following tasks: To Run the File Utilities To Find More Information Replaces all waveforms in reference memories with zero sample values. Replaces the current front panel setup and all setups stored in setup memory with the factory setup. Calculates the checksums of all waveform memory and setup memory locations to verify successful completion of setup and waveform erasure.
Saving Waveforms and Setups 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 3–72), 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.
Saving Waveforms and Setups NOTE. Using this procedure to save an extended acquisition only saves the waveform. In this case, if the trigger position is shown at 0% or 100%, the actual position may be outside the saved waveform. 4. To store a waveform to disk, press To File (side). Then use the general purpose knob to select the exact file from the resulting scrollbar list. Finally, press Save To Selected File (side) to complete the operation. NOTE.
Saving Waveforms and Setups To Change Format To select the format that the oscilloscope uses to save waveforms to a disk: TDS 600B: Press save/recall WAVEFORM ➞ Save Format (main) ➞ Internal, MathCad, or Spreadsheet (side). TDS 500C and TDS700C: Press save/recall WAVEFORM ➞ Normal or Extended (pop-up) ➞ Save Format (main) ➞ Internal, MathCad, or Spreadsheet (side). MathCad and Spreadsheet are only available in the Normal waveform menu. Internal creates files (.WFM or .
Saving Waveforms and Setups To Delete All Waveforms and Setups To Display a Saved Waveform To remove all stored reference waveforms and setups, use the feature called Tek Secure. See To Delete All Setups and Waveforms on page 3–153. To display a waveform in internal reference memory: Press MORE ➞ Ref1, Ref2, Ref3, or Ref4 (main). (See Figure 3–73.) Note that in Figure 3–73, the main menu items Ref2, Ref3, and Ref4 appear shaded while Ref1 does not.
Saving Waveforms and Setups TDS 500C or TDS 700C: Press SAVE/RECALL WAVEFORM ➞ Normal (pop-up) ➞ Recall Wfm To Ref (main) ➞ Recall From File (side). Then use the general purpose knob to select the exact file from the resulting scrollbar list. Only files with .WFM extensions are displayed. Finally, press To Ref1, To Ref2, To Ref3, or To Ref4 (side) to complete the operation.
Saving Waveforms and Setups Consider the following operating characteristics when using autosave. To Run the File Utilities 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. Autosave saves each live waveform into the reference memory that corresponds to the channel (CH 1 to Ref1, CH 2 to Ref2, and so on). Autosave, when executing, erases all four reference memories.
Saving Waveforms and Setups 3. Press File Utilities in the main menu to bring up the File Utilities side menu. (See Figure 3–74.) 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 1 Mbyte or more). To convert the amount to bytes, you simply multiply the Kbytes amount times 1024. Thus, the 690 Kbytes shown in Figure 3–74 = 690 Kbytes x 1024 bytes/Kbyte = 706,560 bytes.
Saving Waveforms and Setups To Delete 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.
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 to Selected Directory. To copy all files, select the *.* entry. The oscilloscope copies all directories recursively.
Saving Waveforms and Setups To Set Overwrite Lock 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 (“?”).
Saving Waveforms and Setups Supported Formats The oscilloscope prints hardcopies of its display in many formats, which allows you to choose from a wide variety of hardcopy devices. It also makes it easier for you to place oscilloscope screen copies into a desktop publishing system.
Saving Waveforms and Setups 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.
Saving Waveforms and Setups Set Hardcopy Parameters. To specify the hardcopy format, layout, and type of port using the hardcopy menu, do the following steps: 1. Press SHIFT ➞ HARDCOPY MENU to bring up the Hardcopy menu. 2. Press Format (main) ➞ 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 Plt, EPS Color Plt, Interleaf, or HPGL (side).
Saving Waveforms and Setups 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 ➞ Settings (main) ➞ Display (pop-up) ➞ Readout Options (main) ➞ Display Date and Time (side) to toggle the setting to On. 2. If you want to set the date and time, skip steps 3 and 4 and continue with step 1 of Set the Date and Time below. Then redo this procedure. 3.
Saving Waveforms and Setups Set the Date and Time. You might need to set the date and time of the oscilloscope. To set those parameters, do the following steps: 1. Press SHIFT ➞ UTILITY ➞ Config (pop-up) ➞ Set Date & Time (main) ➞ Year, Day Month, Hour, or Minute (side). 2. 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 23rd of June.) 3.
Saving Waveforms and Setups 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.
Saving Waveforms and Setups 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 Save to a Disk 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 3–166. 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.
Saving Waveforms and Setups To Print Using a Controller To make your hardcopies, use the procedures that follow. Connect to a Hardcopy Device. To connect a controller with two ports between the oscilloscope and the hardcopy device, connect from the oscilloscope GPIB connector (rear panel) to the controller GPIB port and from the controller RS-232 or Centronics port to the hardcopy device. (See Figure 3–80.) Use the GPIB port to remotely request and receive a hardcopy from the oscilloscope.
Saving Waveforms and Setups NOTE. If you defined another name, use it instead of “DEV1”. Also, remember that the device address of the oscilloscope as set with the IBCONF.EXE program should match the address set in the oscilloscope Utility menu (typically, use “1”). 4. Type: IBWRT “HARDCOPY START” NOTE. Be sure the oscilloscope Utility menu is set to Talk/Listen and not Hardcopy (Talk Only) or you will get an error message at this step.
Saving Waveforms and Setups Communicating with Remote Instruments The TDS Oscilloscope can connect into a system environment, so that you can control it remotely or exchange measurement or waveform data between it and a computer. This subsection explains how to prepare and setup the oscilloscope for control and operation over the IEEE Std 488.2-1987 (GPIB) interface.
Saving Waveforms and Setups Turn on at least two-thirds of the device loads present when you use your network. Include only one cable path between devices on your network. (See Figure 3–81.) Do not create loop configurations. GPIB Device GPIB Device GPIB Device GPIB Device GPIB Device GPIB Device GPIB Device Figure 3–81: Typical GPIB Network Configuration Obtain the Proper Interconnect Cabling. To connect the oscilloscope to a GPIB network, obtain at least one GPIB cable.
Saving Waveforms and Setups Figure 3–82: Stacking GPIB Connectors To Set Up for Remote Operation 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 3–83.
Saving Waveforms and Setups Configure the GPIB Port. You must set two important GPIB parameters: mode and address. To set those parameters: Press SHIFT ➞ UTILITY ➞ System (main) ➞ I/O (pop-up) ➞ Port (main) ➞ GPIB (pop-up) ➞ Configure (main) ➞ Talk/Listen Address, Hardcopy (Talk Only), or Off Bus (side). (See Figure 3–84.) Talk/Listen Address configures the port for controller-based system operation. Use the general purpose knob or the keypad to define the address.
Saving Waveforms and Setups To Find More Information See Printing a Hardcopy, on page 3–164. See the TDS Programmer Manual disk.
Determining Status and Accessing Help The TDS Oscilloscope can display the status of its internal systems. It also provides an on-line help system.
Determining Status and Accessing Help Firmware Version Figure 3–85: Status Menu — System 3–180 TDS 500C, TDS 600B, & TDS 700C User Manual
Determining Status and Accessing Help Displaying the Banner To display the banner (lists firmware version, options, copyright, and patents): Press SHIFT STATUS ➞ Banner (main). (See Figure 3–86.) Figure 3–86: Banner Display Displaying Help To use the on-line help system: Press HELP to provide on-screen information on any front panel button, knob or menu item. (See Figure 3–87.
Determining Status and Accessing Help Figure 3–87: Initial Help Screen When you press that button, the instrument changes mode to support on-line help. Press HELP again to return to regular operating mode. Whenever the oscilloscope is in help mode, pressing any button (except HELP or SHIFT), turning any knob, or pressing any menu item displays help text on the screen that discusses that control. The menu selections that were displayed when HELP was first pressed remain on the screen.
Using Features for Advanced Applications The TDS Oscilloscope provides powerful features for testing and digitally processing the waveforms you acquire.
Using Features for Advanced Applications Figure 3–88: Comparing a Waveform to a Limit Template To do the tasks just listed, do the following procedures: To Create Limit Test Template To use an incoming or stored waveform to create the limit test template, first you 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.
Using Features for Advanced Applications Figure 3–89: Acquire Menu — Create Limit Test Template 4. Press ±V Limit (side). Enter the vertical (voltage) tolerance value using the general purpose knob or keypad. 5. Press ±H Limit (side). Enter the horizontal (time) tolerance value using the general purpose knob or keypad. Tolerance values are expressed in fractions of a major division.
Using Features for Advanced Applications 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 3–39.
Using Features for Advanced Applications 2. Ensure that the side button corresponding to the desired action reads ON. 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 3–164 for details.
Using Features for Advanced Applications Multiple Waveform Comparisons 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: You should set Horizontal Lock to None in the Zoom side menu (push ZOOM and press (repeatedly) Horizontal Lock to None).
Using Features for Advanced Applications To Use Single Wfm Math To perform waveform math, use the More menu (Figure 3–90). The More menu allows you to display, define, and manipulate three math waveforms; the following steps explain how to create a math waveform based on a single source waveform: 1. Press MORE ➞ Math1, Math2, or Math3 (main) ➞ Change Math waveform definition (side) ➞ Single Wfm Math (main). 2.
Using Features for Advanced Applications To Use Dual Wfm Math To create a math waveform that requires two waveform sources, do the following steps: 1. Press MORE ➞ Math1, Math2, or Math3 (main) ➞ Change Math waveform definition (side) ➞ Dual Wfm Math (main). 2. To define the first source waveform, press Set 1st Source to (side) repeatedly to cycle it to the desired channel or reference waveform. 3.
Using Features for Advanced Applications To Average a Math Waveform You can also select whether or not you wish to average a certain math waveform; to do so, perform the following steps: 1. Press MORE ➞ Math1, Math2, or Math3 (main) to select the math waveform to be averaged. 2. Press Average (side) and enter a value with the general purpose knob or the keypad. Any math operations you select for the waveform are performed on an average of multiple acquisitions. 3.
Using Features for Advanced Applications The FFT computes and displays the frequency content of a waveform you acquire as an FFT math waveform.
Using Features for Advanced Applications Normal Waveform of an Impulse Response FFT Waveform of the Magnitude Response FFT Waveform of the Phase Response Figure 3–92: System Response to an Impulse To Create an FFT To obtain an FFT of your 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).
Using Features for Advanced Applications Figure 3–93: 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 .
Using Features for Advanced Applications 8. Press Set FFT Window to (side) repeatedly to choose from the following window types: Rectangular — Best type of window for resolving frequencies that are very close to the same value but worst for accurately measuring the amplitude of those frequencies. Best type for measuring the frequency spectrum of nonrepetitive signals and measuring frequency components near DC.
Using Features for Advanced Applications Figure 3–94: FFT Math Waveform in Math1 To Take Cursor Measurements of an FFT Once you have displayed an FFT math waveform, use cursors to measure its frequency amplitude or phase angle. 1. Be sure MORE is selected in the channel selection buttons and that the FFT math waveform is selected in the More main menu. 2. Press CURSOR ➞ Mode (main) ➞ Independent (side) ➞ Function (main) ➞ H Bars (side). 3.
Using Features for Advanced Applications Figure 3–95 shows the cursor measurement of a frequency magnitude on an FFT. The @: readout reads 0 dB because it is aligned with the 1 VRMS level. The D: 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.
Using Features for Advanced Applications 9. Read the frequency difference between the cursors from the : 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) ➞ Paired (side). 11.
Using Features for Advanced Applications Waveform Record — the complete waveform record acquired from an input channel and displayed from the same channel or a reference memory. The length of this time domain record is user-specified from the Horizontal menu. The waveform record is not a DSP Math waveform. FFT Time Domain Record — that part of the waveform record input to the FFT. This time domain record waveform becomes the FFT math waveform after it’s transformed.
Using Features for Advanced Applications FFTs Transform Time Records to Frequency Records. The FFT time domain record just described is input for the FFT. Figure 3–97 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.
Using Features for Advanced Applications Offset, Position, and Scale The following topics contain information to help you display your FFT properly. Adjust for a Non-Clipped Display. To properly display your FFT waveform, scale the source waveform so it is not clipped. 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).
Using Features for Advanced Applications 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. Acquisition Mode 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.
Using Features for Advanced Applications Whether Zoom is on or off, you can press Reset (main) ➞ Reset Live Factors or Reset All Factors (side) to return the zoomed FFT waveform to no magnification. Zoom always uses either sin(x)/x or linear interpolation when expanding displayed waveforms. To select the interpolation method: press DISPLAY ➞ Setting (main) ➞ Display (pop-up) ➞ Filter (main) ➞ Sin(x)/x or Linear (side).
Using Features for Advanced Applications Filter the input to bandwidth limit it to frequencies below that of the Nyquist frequency. 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.
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: 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.
Using Features for Advanced Applications 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.
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 Time Domain Record Xs FFT Window FFT Time Domain Record After Windowing FFT FFT Frequency Domain Record Figure 3–99: Windowing the FFT Time Domain Record Selecting a Window.
Using Features for Advanced Applications In step 8 (page 3–195) 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.
Using Features for Advanced Applications 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.
Using Features for Advanced Applications FFT Window Type Bandpass Filter –3 dB Bandwidth Highest Side Lobe 0 dB -20 Rectangular Window 0.89 –13 dB 1.28 –43 dB 1.28 –32 dB 1.28 –94 dB -40 -50 0 dB -20 -40 Hamming Window -60 0 dB -20 -40 -60 Hanning Window -80 0 dB -20 -40 Blackman-Harris Window -60 -80 -100 -101 Figure 3–100: FFT Windows and Bandpass Characteristics Waveform Differentiation The Advanced DSP Math capabilities of the TDS Oscilloscope include waveform differentiation.
Using Features for Advanced Applications The math waveform, derived from the sampled waveform, is computed based on the following equation: Y n + (X (n)1) * X n) 1 T 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).
Using Features for Advanced Applications Derivative Math Waveform Source Waveform Figure 3–101: Derivative Math Waveform To Take Automated Measurements 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.
Using Features for Advanced Applications Figure 3–102: 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: 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).
Using Features for Advanced Applications Because of the method the oscilloscope uses to scale the source waveform before differentiating that waveform, the derivative math waveform may be too large vertically to fit on screen — even if the source waveform is only a few divisions on screen. You can use Zoom to reduce the size of the waveform on screen (see Using Zoom that follows), but if your waveform is clipped before zooming, it will still be clipped after it is zoomed.
Using Features for Advanced Applications Whether zoom is on or off, you can press Reset (main) ➞ Reset Live Factors or Reset All Factors (side) to return the zoomed derivative waveform to no magnification. Waveform Integration The Advanced DSP Math capabilities of the TDS Oscilloscope include waveform integration. This capability allows you to display an integral math waveform that is an integrated version of the acquired waveform.
Using Features for Advanced Applications To Create a Integral Math Waveform To obtain an integral math waveform, do the following steps: 1. Connect the waveform to the desired channel input and select that channel. 2. Adjust the vertical and horizontal scales and trigger the display (or press AUTOSET). 3. Press MORE ➞ Math1, Math2, or Math3 (main) ➞ Change Math waveform definition (side) ➞ Single Wfm Math (main). 4. Press Set Single Source to (side).
Using Features for Advanced Applications Integral Math Waveform Source Waveform Figure 3–103: Integral Math Waveform To Take Cursor Measurements Once you have displayed your integrated math waveform, use cursors to measure its voltage over time. 1. Be sure MORE is selected (lighted) in the channel selection buttons and that the integrated math waveform is selected in the More main menu. 2. Press CURSOR ➞ Mode (main) ➞ Independent (side) ➞ Function (main) ➞ H Bars (side). 3.
Using Features for Advanced Applications Integral Math Waveform Source Waveform Figure 3–104: H Bars Cursors Measure an Integral Math Waveform 7. Press Function (main) ➞ 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. 8. Press SELECT to select the alternate cursor. 9. Align the alternate cursor to another point of interest on the math waveform. 10.
Using Features for Advanced Applications 13. Read the following values from the cursor readouts: To Take Automated Measurements Offset, Position, and Scale DC Offset Read the integrated voltage over time between the Xs of both paired cursors in volt-seconds from the : readout. Read the integrated voltage over time between the X of the selected cursor and the reference indicator of the math waveform from the @: readout.
Using Features for Advanced Applications You may be able to avoid saturating your integral waveform if you choose a shorter record length. (Press HORIZONTAL MENU ➞ Record Length (main).) Reducing the sample rate (use the HORIZONTAL SCALE knob) with the source channel selected might also prevent clipping. You can also select AC coupling in the vertical menu of the source waveform or otherwise DC filter it before applying it to the oscilloscope input.
Appendices
Appendix A: Options and Accessories This appendix describes the various options as well as the standard and optional accessories that are available for the TDS Oscilloscope.
Appendix A: Options and Accessories Table A–1: Options (cont.) Option # Label Description 1M 130,000 record length Extend record length from 50,000 samples standard as follows: TDS 520C and TDS 724C: To 250,000 samples on one channel and 130,000 on two channels TDS 540C, TDS 754C, & TDS 784C: To 500,000 samples on one channel, 250,000 on two channels, and 130,000 samples on three or four channels (Option is only available for the models listed above.
Appendix A: Options and Accessories Table A–1: Options (cont.) Option # Label Description 2D Two probes Delete two standard probes normally shipped with the oscilloscope (Option applies only to TDS 520C, TDS 620B, and TDS 724C models.) 2F Advanced DSP math Add advanced DSP math features such as FFT, integration, and differentiation. (Option applies only to TDS 520C and TDS 540C models.) 3I and 3P Color printer Tektronix Phaser 140, 360 dpi, inkjet, color printer.
Appendix A: Options and Accessories Table A–2: Standard Accessories (Cont.
Appendix A: Options and Accessories Accessory Probes The following optional accessory probes are recommended for use with your oscilloscope: P6701B Optical-to-Electrical Analog Converter: 500 to 950 nm (DC to 1 GHz, 1 V/mW) P6703B Optical-to-Electrical Analog Converter: 1100 to 1700 nm (DC to 1 GHz, 1 V/mW) P6723 Optical Logic Probe: 1310 to 1550 nm (20 to 650 Mb/s, –8 to –28 dBm AFTDS Differential Signal Adapter AMT75 75 W to 50 W Adapter P6243 Active, high speed digital voltage pr
Appendix A: Options and Accessories A–6 P5100 High Voltage Passive probe, 2.5 kV, DC to 250 MHz P5205 High Voltage differential probe, 1.3 kV (differential), DC to 100 MHz ADA 400A differential preamp, switchable gain AM 503S — DC/AC 50 MHz Current measurement system, AC/DC. Supplied with A6302 Current Probe AM503S Option 05: DC/AC 100 MHz Current measurement system. Supplied with A6312 Current Probe AM 503S Option 03: DC/AC 100 A Current measurement system, AC/DC.
Appendix A: Options and Accessories Accessory Software The optional accessories listed in Table A–4 are Tektronix software products recommended for use with your oscilloscope.
Appendix A: Options and Accessories A–8 TDS 500C, TDS 600B, & TDS 700C User Manual
Appendix B: Algorithms The TDS Oscilloscope can take 25 automatic measurements. By knowing how it makes these calculations, you may better understand how to use your oscilloscope and how to interpret your results. Measurement Variables The oscilloscope uses a variety of variables in its calculations. These include: High, Low is the value used as the 100% level in measurements such as fall time and rise time.
Appendix B: Algorithms 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 and values as follows: 1. It makes a histogram of the record with one bin for each digitizing level (256 total). 2.
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.
Appendix B: Algorithms MCross Calculations MCross1, MCross2, and MCross3 — refer to the first, second, and third 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, could be a positive or negative crossing, but if is a positive crossing, will be a negative crossing.
Appendix B: Algorithms StartCycle — is the starting time for cycle measurements. It is a floating-point number with values between 0.0 and ( – 1.0), inclusive. = EndCycle — is the ending time for cycle measurements. It is a floating-point number with values between 0.0 and ( – 1.0), inclusive. = Waveform[<0.0 ... RecordLength–1.0>] — holds the acquired data.
Appendix B: Algorithms Measurement Algorithms The automated measurements are defined and calculated as follows: Amplitude Area = – The arithmetic area for one waveform. Remember that one waveform is not necessarily equal to one cycle. For cyclical data you may prefer to use the cycle area rather than the arithmetic area. if = then return the (interpolated) value at .
Appendix B: Algorithms Burst Width Timing measurement. The duration of a burst. 1. Find on the waveform. This is . 2. Find the last (begin the search at and search toward ). This is . This could be a different value from . 3. Compute = – Cycle Mean Amplitude (voltage) measurement. The mean over one waveform cycle. For non-cyclical data, you might prefer to use the Mean measurement.
Appendix B: Algorithms Delay Timing measurement. The amount of time between the and 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. = the time from one crossing on the source waveform to the crossing on the second waveform.
Appendix B: Algorithms Fall Time THF TLF High HighRef LowRef Low Figure B–2: Fall Time 3. From , continue the search, looking for a crossing of . Update if subsequent crossings are found. When a crossing is found, it becomes . (Use linear interpolation if necessary.) 4. = – Frequency Timing measurement. The reciprocal of the period. Measured in Hertz (Hz) where 1 Hz = 1 cycle per second. If = 0 or is otherwise bad, return an error.
Appendix B: Algorithms Low 0% (lowest) voltage reference value calculated. (See High, Low on page B–1.) Using the min-max measurement technique: = Maximum Amplitude (voltage) measurement. The maximum voltage. Typically the most positive peak voltage. Examine all samples from to inclusive, and set equal to the greatest magnitude value found. Mean The arithmetic mean for one waveform. Remember that one waveform is not necessarily equal to one cycle.
Appendix B: Algorithms Negative Duty Cycle 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. NegativeDutyCycle = Negative Overshoot NegativeWidth Period 100% Amplitude (voltage) measurement. NegativeOvershoot = Low * Min Amplitude 100% Note that this value should never be negative (unless High or Low are set out-of-range).
Appendix B: Algorithms Period Timing measurement. Time taken for one complete signal cycle. The reciprocal of frequency. Measured in seconds. = – Phase Timing measurement. The amount of phase shift, expressed in degrees of the target waveform cycle, between the crossings of two different waveforms. Waveforms measured should be of the same frequency or one waveform should be a harmonic of the other.
Appendix B: Algorithms Positive Duty Cycle 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. PositiveDutyCycle = PositiveWidth Period Positive Overshoot 100% Amplitude (voltage) measurement. PositiveOvershoot = Max * High Amplitude 100% Note that this value should never be negative. Positive Width Timing measurement.
Appendix B: Algorithms 3. From , continue the search, looking for a crossing of . Update if subsequent crossings are found. If a crossing is found, it becomes the high rise time or . (Use linear interpolation if necessary.) 4. = – Rise Time TLR THR High HighRef LowRef Low Figure B–3: Rise Time RMS: Amplitude (voltage) measurement. The true Root Mean Square voltage. If = then = the (interpolated) value at .
Appendix B: Algorithms Integration Algorithm The integration algorithm used by the oscilloscope is as follows: ŕ W(t)dt B is approximated by ŕ W(t)dt where: A B ^ A W(t) is the sampled waveform ^ ( )is the continuous function obtained by linear interpolation of W(t) A and B are numbers between 0.0 and –1.0 If A and B are integers, then: ŕ W(t)dt + s B ^ A ) 1) ȍ W(i) ) W(i 2 B*1 i+A where s is the sample interval.
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 to until the sample min and max pair DO NOT straddle .
Appendix B: Algorithms 2. If the pair > , use the minima, else use maxima. If all pairs straddle , 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 If some samples in the waveform are missing or off-scale, the measurements will linearly interpolate between known samples to make an “appropriate” guess as to the sample value.
Appendix B: Algorithms B–18 TDS 500C, TDS 600B, & TDS 700C User Manual
Appendix C: Packaging for Shipment If you ship the TDS Oscilloscope, pack it in the original shipping carton and packing material. If the original packing material is not available, package the instrument as follows: 1. Obtain a corrugated cardboard shipping carton with inside dimensions at least 15 cm (6 in) taller, wider, and deeper than the oscilloscope. The shipping carton must be constructed of cardboard with 170 kg (375 pound) test strength. 2.
Appendix C: Packaging for Shipment C–2 TDS 500C, TDS 600B, & TDS 700C User Manual
Appendix D: Probe Selection The TDS Oscilloscope can use a variety of Tektronix probes for taking different kinds of measurements. To help you decide what type of probe you need, this section introduces the five major types of probes: passive, active, current, optical, and time-to-voltage probes. See Appendix A: Options and Accessories for a list of the optional probes available; see your Tektronix Products Catalog for more information about a given probe. NOTE.
Appendix E: Probe Selection However, their 8 pF to 12 pF (over 60 pF for 1X) capacitive loading can distort timing and phase measurements.
Appendix E: Probe Selection Figure D–1: Typical High Voltage Probes Active Voltage Probes Active voltage probes, sometimes called “FET” probes, use active circuit elements such as transistors. There are three classes of active probes: High speed active Differential active 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.
Appendix E: Probe Selection High Speed Active Probes Active probes offer low input capacitance (1 to 2 pF typical) while maintaining the higher input resistance of passive probes (10 kW to 10 MW). Like ZO probes, active probes are useful for making accurate timing and phase measurements. However, they do not degrade the amplitude accuracy. Active probes typically have a dynamic range of ±8 to ±15 V.
Appendix E: Probe Selection 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 W range, they are especially useful where low loading of the circuit is important.
Appendix E: Probe Selection 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. NOTE.
Appendix E: Inspection and Cleaning Inspect for dirt and damage on and clean the exterior of the TDS Oscilloscope. 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 maintenance is just before oscilloscope adjustment.
Appendix E: 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 could cause personal injury or lead to further damage to the oscilloscope.
Appendix F: Programmer Disk The TDS Family Programmer 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 program runs on a PC-compatible system with Microsoft Windows or Windows 95. (See Figure F–1).
Appendix F: Programmer Disk F–2 TDS 500C, TDS 600B, & TDS 700C User Manual
Glossary
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. AC coupling A type of signal transmission that blocks the DC component of a signal but uses the dynamic (AC) component. Useful for observing an AC signal that is normally riding on a DC signal. Accuracy The closeness of the indicated value to the true value.
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.
Glossary 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 that points to the position around which the waveform contracts or expands when vertical scale is changed. This position is ground when offset is set to 0 V; otherwise, it is ground plus offset.
Glossary Digitizing The process of converting a continuous analog signal such as a waveform to a set of discrete numbers representing the amplitude of the signal at specific points in time. Digitizing is composed of two steps: sampling and quantizing. Display system The part of the oscilloscope that shows waveforms, measurements, menu items, status, and other parameters.
Glossary 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.
Glossary High The value used as 100% in automated measurements (whenever high ref, mid ref, and low ref values are needed as in fall time and rise time measurements). 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 Interleaving TDS 500B and TDS 700A Models Only: A method by which these oscilloscopes attain higher digitizing speeds. The oscilloscope applies the digitizing resources of unused channels (that is, channels that are turned off) to sample those that are in use (turned on). Table 3–2 on page 3–29 lists acquisition rates vs. number of channels that are on. Knob A rotary control.
Glossary 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.
Glossary 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.
Glossary 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.
Glossary 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.
Glossary 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.
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 (moveable) 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. XY format A display format that compares the voltage level of two waveform records point by point.
Glossary Glossary–14 TDS 500C, TDS 600B, & TDS 700C User Manual
Index
Index Numbers 1/seconds (Hz), Cursor menu, 3–131 2 + 2 channel operation, xiv, 1–1, 1–2, Glossary–1 20 MHz, Vertical menu, 3–17 250 MHz, Vertical menu, 3–17 A AC coupling, Glossary–1 AC line voltage, trigger input, 3–64 AC, Main Trigger menu, 3–74 Accept Glitch, Main Trigger menu, 3–93 Accessories, A–1 Optional, A–4–A–8 Probes, A–5 Software, A–7 Standard, A–3, A–7 Accuracy, Glossary–1 Acquire menu, 3–33 Average, 3–33 Average mode, 3–184 Compare Ch1 to, 3–186 Compare Ch2 to, 3–186 Compare Ch3 to, 3–186 Comp
Index Average acquisition mode, 3–30, 3–61, Glossary–2 Average mode, Acquire menu, 3–184 Average, Acquire menu, 3–33 Average, More menu, 3–191 B Buttons CH1, CH2 ...
Index Color, 3–44 How to set, 3–44 Color Deskjet, 3–165 Color Matches Contents, Color menu, 3–47, 3–48 Color menu, 3–44 Bold, 3–45 Change Colors, 3–46 Collision Contrast, 3–48 Color, 3–46, 3–47, 3–48 Color Matches Contents, 3–47, 3–48 Hardcopy, 3–45 Hue, 3–46 Lightness, 3–46 Map Math, 3–47 Map Reference, 3–47 Math, 3–47 Monochrome, 3–45 Normal, 3–45 Options, 3–48 Palette, 3–45 Persistence Palette, 3–45 Ref, 3–48 Reset All Mappings To Factory, 3–49 Reset All Palettes To Factory, 3–49 Reset Current Palette T
Index D Data Source, Main Trigger menu, 3–86 Date/Time On hardcopies, 3–168 To set, 3–169 DC coupling, Glossary–3 DC offset, 3–201 for DC correction of FFTs, 3–201 with math waveforms, 3–201, 3–219 DC, Main Trigger menu, 3–74 Default Model(s), xiv Define Inputs, Main Trigger menu, 3–82, 3–85, 3–87 Define Logic, Main Trigger menu, 3–83, 3–85 Delay by Events, Delayed Trigger menu, 3–110 Delay by Time, Delayed Trigger menu, 3–110 Delay by, Delayed Trigger menu, 3–110 Delay measurement, 3–122, Glossary–3 Delay
Index YT, 3–43 Display, Display menu, 3–39 Display, Status menu, 3–179 Dots, 3–39 Dots style, Display menu, 3–186 Dots, Display menu, 3–39 DPU411–II, Hardcopy menu, 3–167 DPU412, Hardcopy menu, 3–167 Drives, File Utilities menu, 3–164 Dual Wfm Math, More menu, 3–190 Dual Window Zoom, 3–52 Dual Zoom, Zoom menu, 3–54 Dual Zoom Offset, Zoom menu, 3–54 Duty cycle, 2–23, Glossary–8, Glossary–9 E Edge trigger, 3–65, 3–72, Glossary–4 How to set up, 3–73 Readout, 3–72 Edge, Main Trigger menu, 3–72, 3–73 Edges, Me
Index Frame Length, Horizontal menu, 3–60 Frame, Display menu, 3–42 Frame, Horizontal menu, 3–60 Frequency, 2–22, 3–115, Glossary–4 Front Cover removal, 1–7 Front panel, 2–4 Full, Display menu, 3–42 Full, Vertical menu, 3–17 Function, Cursor menu, 3–129, 3–130 Fuse, 1–6, 2–5 H Bars, Cursor menu, 3–129, 3–130 H Limit, Acquire menu, 3–185 Hamming window, 3–195 Hanning window, 3–195 Hard Disk, Option HD, A–1 Hardcopy, 3–164, Glossary–5 How to print (controller), 3–172 How to print (no controller), 3–169 How
Index Histograms, 3–133 HistoMasks, Status menu, 3–179 Hits in Box, 3–135 Holdoff, trigger, 3–66, Glossary–6 Horiz Pos, Horizontal menu, 3–22 Horiz Scale, Horizontal menu, 3–22 Horizontal Bar cursors, 3–127, Glossary–6 Control, 3–19–3–62 Menu, 3–68 Position, 3–19 Readouts, 3–18 Scale, 3–19 SCALE knob, 2–14 System, 2–14 Horizontal menu, 3–108 Delayed Only, 3–108 Delayed Runs After Main, 3–22, 3–108 Delayed Scale, 3–22 Delayed Triggerable, 3–22, 3–110 Extended acquisition length, 3–22 FastFrame, 3–60 FastFra
Index Level, Telecom Trigger menu, 3–106 Level, Trigger, 3–68 LF Rej, Main Trigger menu, 3–74 Lightness, Color menu, 3–46 Limit Test Condition Met, Acquire menu, 3–187 Limit Test Setup, Acquire menu, 3–186, 3–187 Limit Test Sources, Acquire menu, 3–186 Limit Test, Acquire menu, 3–187 Limit Testing, Incompatible with InstaVu, 3–58 Limit testing, 3–183 Linear interpolation, 3–28, 3–42, Glossary–6 Linear interpolation, Display menu, 3–42 Logic trigger, 3–65, 3–78 Definitions, 3–78 Pattern, 3–77, Glossary–7 Re
Index Math1/2/3, More menu, 3–191 Maximum, 3–115, Glossary–7 Mean, 3–115, 3–135, Glossary–8 Mean +– 1 StdDev, 3–135 Mean +– 2 StdDev, 3–135 Mean +– 3 StdDev, 3–135 Mean dBm, 3–116, B–10 MEASURE button, 3–117, 3–135 Measure Delay menu Create Measrmnt, 3–123 Delay To, 3–122 Edges, 3–123 Measure Delay To, 3–122 OK Create Measurement, 3–123 Measure Delay To, Measure Delay menu, 3–122 Measure menu, 3–117, 3–124 Gating, 3–119 High Ref, 3–121 High-Low Setup, 3–120 Histogram, 3–120 Low Ref, 3–121 Mid Ref, 3–121 Mi
Index Measure, 3–117, 3–124 More, 3–158, 3–189, 3–193, 3–211 Operation, 2–7 Pop-up, 2–8, Glossary–9 Save/Recall, 3–152 Save/Recall Acquisition, 3–156, 3–159 Save/Recall Waveform, 3–155 Setup, 2–10, 3–11 Status, 3–179 Utility, 3–166 Mid Ref, Measure menu, 3–121 Mid2 Ref, Measure menu, 3–121 Min-Max, Measure menu, 3–120 Minimum, 3–115, Glossary–8 Mode & Holdoff, Main Trigger menu, 3–75 Model number location, 2–3 Models, Manual references to, xiv Models, key features and differences, 1–2 Monochrome, Color men
Index P P6205 Active Probe, 1–5 P6701A/B with calibration, A–2 P6703A/B with calibration, A–2 Packaging, C–1 Paired cursor, 3–127 PAL, Display menu, 3–42 Palette, Color menu, 3–45 Palette, Hardcopy menu, 3–167 Passive voltage probes, D–1 Pattern trigger, 3–76 How to setup, 3–81 PCX, 3–165 PCX Color, Hardcopy menu, 3–167 PCX, Hardcopy menu, 3–167 Peak detect acquisition mode, 3–30, Glossary–9 Peak Detect, Acquire menu, 3–33 Peak Hits, 3–135 Peak to peak, 3–115, Glossary–9 Period, 3–116, Glossary–9 Persisten
Index Edge trigger, 3–72 General purpose knob, 2–6 Logic trigger, 3–79 Measurement, 3–116, 3–117 Record view, 2–6 Snapshot, 3–123 Time base, 2–6 Trigger, 2–6, 3–71 Trigger Level Bar, 3–40 Trigger Point, 3–40 Readout, Cursor, Paired, 3–212 Readout, cursor H-Bars, 3–196, 3–212, 3–217 Paired cursors, 3–198, 3–219 V-Bars, 3–198, 3–212, 3–218 Readout, Display menu, 3–41, 3–43 Real time sampling, 3–26 Real-time sampling, Glossary–10 Rear panel, 2–5 Recall, Setups, 3–151 Recall Factory Setup, Save/Recall Setup me
Index user status, 3–152 Save/Recall WAVEFORM button, 3–155, 3–160 Save/Recall Waveform menu, 3–155 active status, 3–155 Autosave, 3–159 Delete Refs, 3–157 empty status, 3–155 File Utilities, 3–160 Ref1, Ref2, Ref3, Ref4, File, 3–158 Save Acq, 3–156 Save Format, 3–157 Save Waveform, 3–155 Saving Acquisitions, 3–154 Waveforms, 3–154 Saving and recalling acquisitions, 3–154 Saving and recalling setups, 2–28, 3–151 Saving and recalling waveforms, 3–154 Saving Waveforms and Setups, 3–151 Scale, vertical, 3–201
Index Histo/Masks, 3–179 I/O, 3–179 System, 3–179 Trigger, 3–179 Waveforms, 3–179 StdDev, 3–135 Stop After Limit Test Condition Met, Acquire menu, 3–187 Stop After, Acquire menu, 3–35, 3–187 Style, Display menu, 3–39 Switch, principal power, 1–7, 2–5 System, Status menu, 3–179 System, Utility menu, 3–166 T Talk/Listen Address, Utility menu, 3–177 Tek Secure, 3–153, Glossary–12 Tek Secure Erase Memory, Utility menu, 3–153 Telecom Standard, Telecom Trigger menu, 3–105 Telecom trigger, 3–103 How to set up, 3
Index Triggering on Waveforms, 3–63 Triggering, Auto mode, Incompatible with InstaVu, 3–58 True for less than, Main Trigger menu, 3–83 True for more than, Main Trigger menu, 3–83 Type Logic, Main Trigger menu Logic, 3–81, 3–85, 3–86 Pulse, 3–97 Type Pulse, Main Trigger menu, 3–91 Type, Main Trigger menu, 3–72, 3–73, 3–96, 3–101 Pulse, 3–93 U Undershoot, Glossary–8 user, Saved setup status, 3–152 UTILITY button, 3–142, 3–166, 3–176 Utility Menu OK Erase Ref & Panel Memory, 3–153 Tek Secure Erase Memory, 3–
Index How to set up, 3–96–3–112 Width, Main Trigger menu, 3–92, 3–96 Window, 3–206 Blackman-Harris, 3–195, 3–207, 3–210 characteristics of, 3–208 Hamming, 3–195, 3–207, 3–210 Hanning, 3–195, 3–207, 3–210 rectangular, 3–195, 3–207, 3–210 rectangular vs.
