Tektronix TDS 540, TDS 520 User Manual

User Manual

TDS 520 & 540
Digitizing Oscilloscopes

070-8317-01

This document supports Version 2 firmware.

Please check for change information at the rear
of this manual.

First Printing: March 1992
Last Revised: November 1992

Copyright E Tektronix, Inc. 1991, 1992. All rights reserved.
T ektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes

that in all previously published material. Specifications and price change privileges reserved.
Printed in the U.S.A.
T ektronix, Inc., P.O. Box 1000, Wilsonville, OR 97070–1000
TEKTRONIX and TEK are registered trademarks of T ektronix, Inc.

Microsoft is a registered trademark of Microsoft Corporation
IBM is a registered trademark of International Business Machines
GPIB-PCII and GPIB-PCIIA are registered trademarks of National Instruments Corporation
Epson is a registered trademark of Epson America, Inc.
Interleaf is a trademark of Interleaf, Inc.
PostScript is a registered trademark of Adobe Systems Incorporated

WARRANTY

T ektronix warrants that the products that it manufactures and sells will be free from defects in materials and
workmanship for a period of three (3) years from the date of shipment. If a product proves defective during this
warranty period, T ektronix, at its option, either will repair the defective product without charge for parts and labor,
or will provide a replacement in exchange for the defective product.

In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration
of the warranty period and make suitable arrangements for the performance of service. Customer shall be
responsible for packaging and shipping the defective product to the service center designated by T ektronix, with
shipping charges prepaid. Tektronix shall pay for the return of the product to Customer if the shipment is to a
location within the country in which the T ektronix service center is located. Customer shall be responsible for
paying all shipping charges, duties, taxes, and any other charges for products returned to any other locations.

This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate
maintenance and care. T ektronix shall not be obligated to furnish service under this warranty a) to repair damage
resulting from attempts by personnel other than T ektronix representatives to install, repair or service the product;
b) to repair damage resulting from improper use or connection to incompatible equipment; c) to repair any
damage or malfunction caused by the use of non-T ektronix supplies; or d) to service a product that has been
modified or integrated with other products when the effect of such modification or integration increases the time
or difficulty of servicing the product.

THIS WARRANTY IS GIVEN BY TEKTRONIX IN LIEU OF ANY OTHER WARRANTIES, EXPRESS
OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. TEKTRONIX’
RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND
EXCLUSIVE REMEDY PROVIDED TO THE CUST OMER FOR BREACH OF THIS WARRANTY.
TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT , SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR
THE VENDOR HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.

This apparatus has been designed and tested in accordance with IEC Publication 348, Safety Requirements for
Electronic Measuring Apparatus, and has been supplied in a safe condition. This manual contains some
information and warnings which have to be followed by the user to ensure safe operation and to retain the
apparatus in safe condition.

The apparatus has been designed for indoor use. It may occasionally be subjected to temperatures between +5_ C
and –10_ C without degradation of its safety.

Welcome

This is the User Manual for the TDS 520 and TDS 540 Digitizing Oscillo­scopes.

Related Manuals

If you are a new user, try the
operation of your digitizing oscilloscope.

Concepts

The
scope. These articles help you understand why your instrument works the
way it does.

Use the
for a complete list of tasks covered in that section.

Appendices

The
tion, and other useful information.

The following documents are related to the use or service of the digitizing
oscilloscope.

H

The
070-8318-03) describes using a computer to control the digitizing oscillo­scope through the GPIB interface.

H

The
gives you a quick overview of how to operate your digitizing oscilloscope.

H

The
070-8582-00) describes use of the Advanced DSP Math option (for TDS
oscilloscopes equipped with that option only).

section covers basic principles of the operation of the oscillo-

In Detail

TDS Family Programmer Manual

TDS 520 & 540 Reference

TDS Family Option 2F Instruction Manual

section to learn how to perform specific tasks. See page 3-1

provide an option and accessories listing, product specifica-

Tutorial

section to become familiar with the

(Tektronix part number

(Tektronix part number 070-8316-01)

(Tektronix part number

TDS 520 & TDS 540 User Manual

H

H

H

TDS Family Option 13 Instruction Manual

The
070-8567-00) describes using the optional Centronicsr and RS-232
interfaces for obtaining hardcopy (for TDS oscilloscopes equipped with
that option only).

TDS 520

The
070-8603-00) tells how to verify the performance of the digitizing oscillo­scope.

TDS 520 Service Manual

The

TDS 540 Service Manual

the
maintaining and servicing your digitizing oscilloscope to the module level.

&

TDS 540 Performance Verification

(Tektronix part number 070-8312-01) and

(070-8314-01) provide information for

(Tektronix part number

(Tektronix part number

i

Conventions

In the

Tutorial

contain steps of instructions for you to perform. To keep those instructions
clear and consistent, this manual uses the following conventions:

H

Names of front panel controls and menu labels appear in boldface print.

H

Names also appear in the same case (initial capitals, all uppercase, etc.)
in the manual as is used on the oscilloscope front panel and menus. Front
panel names are all upper case letters, for example, VERTICAL MENU,
CH 1, etc.

H

Instruction steps are numbered. The number is omitted if there is only
one step.

H

When steps require that you make a sequence of selections using front
panel controls and menu buttons, an arrow ( ➞

between a front panel button and a menu, or between menus. Also,
whether a name is a main menu or side menu item is clearly indicated:

Press VERTICAL MENU ➞ Coupling (main) ➞ DC (side) ➞ Band-
width (main) ➞ 100 MHz (side).

Using the convention just described results in instructions that are graphi­cally intuitive and simplifies procedures. For example, the instruction just
given replaces these five steps:

1. Press the front panel button VERTICAL MENU.

and

In Detail

sections, you will find various procedures which

) marks each transition

2. Press the main menu button Coupling.

3. Press the side-menu button DC.

4. Press the main menu button Bandwidth

5. Press the side menu button 100 MHz

H

Sometimes you may have to make a selection from a popup menu: Press
TRIGGER MENU ➞ Type (main) ➞ Edge (popup). In this example, you
repeatedly press the main menu button Type until Edge is highlighted in
the pop-up menu.

ii

Welcome

T utorial

Contents

Product Description v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Safety vi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Start Up viii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overview 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Example 1: Displaying a Waveform 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . .

Example 2: Multiple Waveforms 1-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Example 3: Automated Measurements 1-12. . . . . . . . . . . . . . . . . . . . . . . .

Example 4: Saving Setups 1-18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Concepts

In Detail

Overview 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Triggering 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Acquisition 2-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Scaling and Positioning Waveforms 2-13. . . . . . . . . . . . . . . . . . . . . . . . . .

Measurements 2-17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overview 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

At a Glance 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Acquisition Modes 3-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Autoset 3-18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cursor Measurements 3-20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Delayed Triggering 3-25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Display Modes 3-31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TDS 520 & TDS 540 User Manual

Edge Triggering 3-36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Hardcopy 3-40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

iii

Help 3-48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Horizontal Control 3-49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Limit Testing 3-53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Logic Triggering 3-58. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Measurement System 3-66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Probe Accessories 3-77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Probe Cal 3-84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Probe Compensation 3-90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Probe Selection 3-92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Pulse Triggering 3-99. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Remote Communication 3-106. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Saving and Recalling Setups 3-110. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Saving and Recalling Waveforms 3-112. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Selecting Channels 3-115. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Signal Path Compensation 3-117. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Appendices

Glossary & Index

Status 3-119. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Triggering 3-120. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Vertical Control 3-124. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Waveform Math 3-127. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Zoom 3-130. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Appendix A: Options and Accessories A-1. . . . . . . . . . . . . . . . . . . . . . . .

Appendix B: Specification A-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Appendix C: Algorithms A-25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Appendix D: Packaging for Shipment A-39. . . . . . . . . . . . . . . . . . . . . . . . .

Appendix E: Factory Initialization Settings A-41. . . . . . . . . . . . . . . . . . . .

Change Information

i

Contents

Product Description

Your Tektronix digitizing oscilloscope is a superb tool for acquiring, displaying,
and measuring waveforms. Its performance addresses the needs of both
benchtop lab and portable applications with the following features:

H

500 MHz maximum analog bandwidth.

H

1 Gigasample/second maximum digitizing rate (TDS 540);
500 Megasamples/second maximum digitizing rate (TDS 520).

H

Four-channel acquisition—the TDS 540 offers four full-featured channels;
the TDS 520 offers two full-featured channels and two channels with
limited vertical scale selections: 100 mV, 1 V, and 10 V.

H

Waveform Math—Invert a single waveform and add, subtract, and multiply
two waveforms. On instruments equipped with option 2F, integrate or
differentiate a single waveform or perform an FFT (fast fourier transform)
on a waveform to display its magnitude or phase versus its frequency.

H

Eight-bit digitizers.

H

Up to 15,000-point record length per channel (50,000-point optional).

H

Full GPIB software programmability. GPIB hardcopy output. On instru­ments equipped with option 13, hardcopy output using the RS-232 or
Centronics ports.

H

Complete measurement and documentation capability.

H

Intuitive graphic icon operation blended with the familiarity of traditional
horizontal and vertical knobs.

H

On-line help at the touch of a button.

TDS 520 & TDS 540 User Manual

v

Safety

Please take a moment to review these safety precautions. They are provided
for your protection and to prevent damage to the digitizing oscilloscope. This
safety information applies to all operators and service personnel.

Symbols and Terms

These two terms appear in manuals:

H

statements identify conditions or practices that could result in

damage to the equipment or other property.

H

statements identify conditions or practices that could result in

personal injury or loss of life.

These two terms appear on equipment:

CAUTION

H

indicates a personal injury hazard not immediately accessible
as one reads the marking or a hazard to property including the equipment
itself.

H

DANGER

indicates a personal injury hazard immediately accessible as

one reads the marking.

This symbol appears in manuals:

vi

Static-Sensitive Devices

These symbols appear on equipment:

DANGER

High Voltage

Protective

ground (earth)

terminal

ATTENTION

Refer to

manual

Safety

Safety

Specific Precautions

Observe all of these precautions to ensure your personal safety and to pre­vent damage to either the digitizing oscilloscope or equipment connected to it.

Power Source

The digitizing oscilloscope is intended to operate from a power source that will
not apply more than 250 V
either supply conductor and ground. A protective ground connection, through
the grounding conductor in the power cord, is essential for safe system
operation.

between the supply conductors or between

rms

Grounding the Digitizing Oscilloscope

The digitizing oscilloscope is grounded through the power cord. To avoid
electric shock, plug the power cord into a properly wired receptacle where
earth ground has been verified by a qualified service person. Do this before
making connections to the input or output terminals of the digitizing oscillo­scope.

Without the protective ground connection, all parts of the digitizing oscillo­scope are potential shock hazards. This includes knobs and controls that may
appear to be insulators.

Use the Proper Power Cord

Use only the power cord and connector specified for your product. Use only a
power cord that is in good condition.

Use the Proper Fuse

To avoid fire hazard, use only the fuse specified in the parts list for your
product, matched by type, voltage rating, and current rating.

Do Not Remove Covers or Panels

To avoid personal injury, do not operate the digitizing oscilloscope without the
panels or covers.

Electric Overload

Never apply a voltage to a connector on the digitizing oscilloscope that is
outside the voltage range specified for that connector.

Do Not Operate in Explosive Atmospheres

The digitizing oscilloscope provides no explosion protection from static dis­charges or arcing components. Do not operate the digitizing oscilloscope in
an atmosphere of explosive gases.

TDS 520 & TDS 540 User Manual

vii

Start Up

Before you use the digitizing oscilloscope, ensure that it is properly installed
and powered on.

Operation

To properly install and power on the digitizing oscilloscope, do the following:

Installation

1. Be sure you have the appropriate operating environment. Specifications
for temperature, relative humidity, altitude, vibrations, and emissions are
included in

2. Leave space for cooling. Do this by verifying that the air intake and ex­haust holes on the sides of the cabinet (where the fan operates) are free
of any airflow obstructions. Leave at least 2 inches (5.1 cm) free on each
side.

Appendix B: Specification

WARNING

To avoid electrical shock, be sure that the power cord is discon­nected before checking the fuse.

3. Check the fuse to be sure it is the proper type and rating (Figure i). You
can use either of two fuses. Each fuse requires its own cap (see Table i).
The digitizing oscilloscope is shipped with the UL approved fuse installed.

at the rear of this manual.

viii

4. Check that you have the proper electrical connections. The digitizing
oscilloscope requires 90 to 250 VAC
63 Hz, and may require up to 300 W.

5. Connect the proper power cord from the rear-panel power connector
(Figure i) to the power system.

, continuous range, 47 Hz to

rms

Start Up

Power Connector

Principal Power Switch

Fuse

Start Up

Figure i: Rear Panel Controls Used in Start Up

Table i: Fuse and Fuse Cap Part Numbers

Fuse

.25 inch  1.25 inch (UL 198.6, 3AG):

Fuse Part
Number

Fuse Cap Part
Number

159–0013–00 200–2264–00

6 A FAST, 250 V.
5 mm  20 mm (IEC 127): 5 A (T),

159–0210–00 200–2265–00

250 V.

Power On

1. Check that the rear-panel principal power switch is on (Figure i). The
principal power switch controls all AC power to the instrument.

2. If the oscilloscope is not powered on (the screen is blank), push the
front-panel ON/STBY button to toggle it on (Figure ii).

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 digitizing oscilloscope is installed, you can leave the principal
power switch on and use the ON/STBY button as the power switch.

TDS 520 & TDS 540 User Manual

ix

ON/STBY Button

Figure ii: ON/STBY Button

Self Test

The digitizing oscilloscope automatically performs power-on tests each time it
is turned on. It will come up with a display screen that states whether or not it
passed self test. (If the self test passed, the status display screen will be
removed after a few seconds.)

Check the self test results.
If the self test fails, call your local Tektronix Service Center. Depending on the

type of failure, you may still be able to use the oscilloscope before it is serv­iced.

Before You Begin

x

Power Off

Press the ON/STBY switch to turn off the oscilloscope.

Now that you have set up your oscilloscope for operation, you should know
about two features that help to ensure maximum accuracy for your most
critical measurements,

Signal Path Compensation (SPC)

the current ambient temperature, helping to ensure maximum possible accu­racy for your most critical measurements. See
page 3-117 for a description of and operating information on this key feature.

Signal Path Compensation

lets you compensate your oscilloscope for

and

Probe Cal.

Signal Path Compensation

Start Up

on

Start Up

Probe Cal

lets you compensate any channel of your oscilloscope for the effect
of the probe on gain accuracy and offset accuracy. Like SPC, Probe Cal helps
ensure maximum possible accuracy for your most critical measurements. See

Probe Cal

on page 3-84 for a description of and operating information on this

feature.

TDS 520 & TDS 540 User Manual

xi

xii

Start Up

Tutorial

Overview

This section contains four examples that show you how to operate the basic
functions of the digitizing oscilloscope. Use the
on page 3-2) to help you locate the correct knobs, buttons, and menus.

At a Glance

section (starting

Setting Up for the
Examples

Example 1

H

and adjust waveforms, and use the autoset function.

Example 2

H

Example 3

H

Example 4

H

setups.

Before you perform these examples, read
decide to skip this tutorial, use the
about the digitizing oscilloscope arrangement and specific functions.

All the examples use the same setup. Once you perform this setup, you do
not have to change the signal connections for any of the other examples.

Remove all probes and signal inputs from the input BNC connectors along the
lower right of the front panel. Then, using one of the probes supplied with the
digitizing oscilloscope, connect from the CH 1 connector to the PROBE
COMPENSATION connectors (Figure 1-1).

teaches you how to reset the digitizing oscilloscope, display

explains how to add, control, and delete multiple waveforms.
introduces you to the automated measurement system.

discusses saving and recalling the digitizing oscilloscope

Conventions

Concepts

and

on page ii. If you

In Detail

sections to learn

TDS 620 & 640 User Manual

Figure 1-1: Connecting a Probe for the Examples

1Ć1

Example 1: Displaying a Waveform

In this first example you learn about resetting the digitizing oscilloscope,
displaying and adjusting a waveform, and using the autoset function.

Resetting the
Digitizing
Oscilloscope

SETUP Button

All examples in the tutorial begin by resetting the digitizing oscilloscope to a
known factory default state. Reset the oscilloscope when 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 (Fig-

ure 1-2).

Figure 1-2: SETUP Button Location

The digitizing oscilloscope displays
screen. Figure 1-3 shows the Setup main menu.

main menus

along the bottom of the

1Ć2

OK Confirm Factory Init

Menu Item and Button

Recall Factory Setup

Menu Item and Button

Figure 1-3: The Displayed Setup Menu

Section Name (Nm:Sect)

Example 1: Displaying a Waveform

2. Press the button directly below the Recall Factory Setup menu item.

The display shows

side menus

along the right side of the screen. The

buttons to select these side menu items are to the right of the side menu.
Because an accidental instrument reset could destroy a setup that took a

long time to create, the digitizing oscilloscope asks you to verify the
Recall Factory Setup selection (see Figure 1-3).

3. Press the button to the right of the OK Confirm Factory Init side menu

item.

NOTE

This manual uses the following notation to represent the sequence
of selections you made in steps 1, 2 and 3:

UP ➞ 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 1-4) to be sure the oscilloscope

triggers on the input signal.

Press save/recall SET-

TDS 620 & 640 User Manual

SET LEVEL TO 50% Button

Figure 1-4: Trigger Controls

1Ć3

Example 1: Displaying a Waveform

Display Elements

Figure 1-5 shows the display that results from the instrument reset. There are
several important points to observe:

H

trigger level bar

The

shows that the waveform is triggered at a level near

50% of its amplitude (from step 4).

H

trigger position indicator

The

shows that the trigger position of the wave-

form is located at the horizontal center of the graticule.

H

channel reference indicator

The

shows the vertical position of channel 1
with no input signal. This indicator points to the ground level for the
channel when its vertical offset is set to 0 V in the vertical menu; when

not

vertical offset is

H

trigger readout

The

set to 0 V, it points to the vertical offset level.

shows that the digitizing oscilloscope is triggering on
channel 1 (Ch1) on a rising edge, and that the trigger level is about
200-300 mV.

H

time base readout

The

shows that the main time base is set to a horizon-

tal scale of 500ms/div.

H

channel readout

The

indicates that channel 1 (Ch1) is displayed with DC
coupling. (In AC coupling, ~ appears after the volts/div readout.) The
digitizing oscilloscope always displays channel 1 at reset.

Trigger Level

Bar

Trigger Position

Indicator

Channel Reference

Indicator

Trigger Readout

Time Base Readout

Channel Readout

Running: 100kS/s Sample

Figure 1-5: The Display After Factory Initialization

Right now, the channel, time base, and trigger readouts appear in the grati­cule area because a menu is displayed. You can press the CLEAR MENU
button at any time to remove any menus and to move the readouts below the
graticule.

1Ć4

Section Name (Nm:Sect)

Example 1: Displaying a Waveform

Adjusting the
Waveform Display

The display shows the probe compensation signal. It is a 1 kHz square wave
of approximately 0.5 V amplitude. You can adjust the size and placement of
the waveform using the front-panel knobs.

Figure 1-6 shows the main VERTICAL and HORIZONTAL sections of the
front panel. Each has SCALE and POSITION 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.

Using Autoset

Figure 1-6: The VERTICAL and HORIZONT AL Controls

2. Turn the vertical POSITION knob first one direction, then the other.
Observe the change in the displayed waveform. Then return the wave­form to the center of the graticule.

3. Turn the horizontal SCALE knob one click clockwise. Observe the time
base readout at the bottom of the display. The time base should be set to
200ms/div now, and you should see two complete waveform cycles on
the display.

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.

When you reset the digitizing oscilloscope, you see a clear, stable display of
the probe compensation waveform. That is because the probe compensation
signal happens to display well at the default settings of the digitizing oscillo­scope.

TDS 620 & 640 User Manual

1Ć5

Example 1: Displaying a Waveform

1. To create an unstable display, slowly turn the trigger MAIN LEVEL knob
(see Figure 1-7) first one direction, then the other. Observe what happens
when you move the trigger level above the highest part of the displayed
waveform. Leave the trigger level in that untriggered state.

2. Press AUTOSET (see Figure 1-8) and observe the stable waveform
display.

MAIN LEVEL Knob

Figure 1-7: TRIGGER Controls

AUTOSET Button

Figure 1-8: AUTOSET Button Location

Figure 1-9 shows the display after pressing AUTOSET. If necessary, you can
adjust the waveform now by using the knobs discussed earlier in this exam­ple.

1Ć6

Section Name (Nm:Sect)

Example 1: Displaying a Waveform

Figure 1-9: The Display After Pressing Autoset

NOTE

If the corners on your displayed signal look rounded or pointed (see
Figure 1-10), then you may need to compensate your probe. The

Probe Compensation

Figure 1-10: Display Signals Requiring Probe Compensation

section on page 3-90 explains how to do that.

TDS 620 & 640 User Manual

1Ć7

Example 2: Multiple Waveforms

In this example you learn how to display and control more than one waveform
at a time.

Adding a Waveform

The VERTICAL section of the front panel contains the channel selection
buttons. On the TDS 640 Digitizing Oscilloscope, these are CH 1, CH 2,

CH 3, CH 4, and MORE (Figure 1-11); on the TDS 620, they are CH 1, CH 2,
AUX 1, AUX 2, and MORE.

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Figure 1-11: The Channel Buttons and Lights (TDS 540 Shown)

Each of the channel (CH) buttons has a light above its label. Right now, the
CH 1 light is on. That light indicates that the vertical controls are set to adjust

channel 1.
The following steps adds a waveform to the display.

1. If you are not continuing from the previous example, follow the instruc­tions on page 1-1 under the heading “Setting Up for the Examples.”

Section Name (Nm:Sect)

Example 2: Multiple Waveforms

2. Press SETUP ➞ Recall Factory Setup (main) ➞ OK Confirm Factory
Init (side).

3. Press AUTOSET.

4. Press CH 2.
The display shows a second waveform, which represents the signal on

channel 2. Since there is nothing connected to the CH 2 input connector,

this waveform is a flat line.
There are several other important things to observe:

H

The channel readout on the display now shows the settings for both
Ch1 and Ch2.

H

There are two channel indicators at the left edge of the graticule.
Right now, they overlap.

H

The light next to 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.

H

The trigger readout still indicates that the trigger is detecting trigger
events on Ch1. The trigger source is not changed simply by adding a
channel. (You can change the trigger source by using the TRIGGER
MENU button to display the trigger menu.)

5. Turn the vertical POSITION knob clockwise to move the channel 2 wave-

form up on the graticule. You will notice that the channel reference indica­tor for channel 2 moves with the waveform.

6. Press VERTICAL MENU ➞ Coupling (main).

The VERTICAL MENU button displays a menu that gives you control
over many vertical channel parameters (Figure 1-12). Although there can
be more than one channel displayed, the vertical menu and buttons only
adjust the selected channel.

Each menu item in the Vertical menu displays a side menu. Right now,
the Coupling item in the main menu is highlighted, which means that the
side menu shows the coupling choices. At the top of the side menu, the
menu title shows the channel affected by the menu choices. That always
matches the lighted channel button.

7. Press W (side) to toggle the selection to 50 W. That changes the input

coupling of channel 2 from 1 MW to 50 W. The channel readout for chan­nel 2 (near the bottom of the graticule) now shows an W indicator.

TDS 620 & 640 User Manual

1Ć9

Example 2: Multiple Waveforms

Ch2 Reference Indicator

Side Menu Title

Running: 100kS/s Sample

Changing Controls
to Another Channel

Figure 1-12: The Vertical Main Menu and Coupling Side Menu

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.

1. Press CH 1.
Observe that now the side menu title shows Ch1 (Figure 1-13), and that

the light above CH 1 is lighted. The highlighted menu item in the side
menu has changed from the 50W channel 2 setting to the 1MW imped­ance setting of channel 1.

2. Press CH 2 ➞ W (side) to toggle the selection to 1MW. That returns the
coupling impedance of channel 2 to its initial state.

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Section Name (Nm:Sect)

Side Menu Title

Example 2: Multiple Waveforms

Running: 100kS/s Sample

Removing a
Waveform

Figure 1-13: The Menus After Changing Channels

Pressing the WAVEFORM OFF button removes the waveform for the current-
ly selected channel. If the waveform you want to remove is not already se­lected, select that channel using the channel (CH) button.

1. Press W AVEFORM OFF (under the vertical SCALE knob).
Since the CH 2 light was on when you pressed the WAVEFORM OFF

button, the channel 2 waveform was removed.
The channel (CH) lights now indicate channel 1. Channel 1 has become

the selected channel. When you remove the last waveform, all the CH
lights are turned off.

2. Press W AVEFORM OFF again to remove the channel 1 waveform.

TDS 620 & 640 User Manual

1Ć11

Example 3: Automated Measurements

In this example you learn how to use the automated measurement system to
get numeric readouts of important waveform characteristics.

Displaying
Automated
Measurements

To use the automated measurement system, you must have a stable display
of your signal. Also, the waveform must have all the segments necessary for
the measurement you want. For example, a rise time measurement requires
at least one rising edge, and a frequency measurement needs at least one
complete cycle.

1. If you are not continuing from the previous example, follow the instruc­tions on page 1-1 under the heading “Setting Up for the Examples.”

2. Press SETUP ➞ Recall Factory Setup (main) ➞ OK Confirm Factory
Init (side).

3. Press AUTOSET.

4. Press MEASURE to display the Measure main menu (see Figure 1-14).

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Figure 1-14: Measure Main Menu and Select Measurement Side Menu

Section Name (Nm:Sect)