Tektronix 2467 Instrument Interfacing Guide

Tektronyx

24XSAl2467 Option 10

Instrument Interfacing Guide

70-6282-00

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TEK . INTER-OFFICE COMlvllJNlCATlON

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Sohn Martin

94-540

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Juno 25, 1991

Frank Gray, SO-PAT

FWW

M3KC.T

GIDEP permit request

In response to

Government Tektronix operator, Tektronix, Inc. hereby grant6 such permission for distribution

of

such documents to any

in the Metrology Data Interchange Data Base that copyright notice and ownership statement exactly a-& it appears

in the original, together with the Legend "Reproduded with pemieeion,a

aeon% 1[

all copies

This permission has been approved by the Intellectual

Industry

Committee of Tektronix

ded

to GIDEP to grovide’the requested permission.

the request Exchange

service and

GTDEP

of the original work include the entire

to grant permission to

Pro

ram (GPDEP) to reproduce nstruction manuals,

P

user that is a full participant

of

GIDEP provided

and

a

copy of this memo may

the

geG&dy

Group Pat&t Counsel Group Patent C&nsal v

Tektronjx

24XSAl2467 Option 10 Instrument Interfacing Guide

070-6282-00

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

First Edition: September 1986 Last Revised: February 1988

_--... -. -- ------

pending. Information in this publication supercedes that in all previously published material. Specifications and price change privileges reserved.

Printed in the U.S.A. Tektronix, Inc., P.O. Box 1000, Wilsonville, OR 97070-1000 TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

.......................................................................................................... iv

Tables Operators Safety Summary

Introduction

1

........................................................................

2 Measurement Capabilities and Ch8racteristics

Cursors.. Frequency and Time Interval.. Repetitive Time intervals Non-Repetitive Time Intervals..

Peak Amplitude.

Programming Techniques

3

4

Self-Contained Programs.. .....................................................................

Easy Programs Full-Power Programs

System

Setting GPIB System Parameters.. .......................................................

Instrument Configuration IBM PC/XT/AT Configuration

Program Considerations at Power-on.

................................................................................................. 2-l

..........................................................................

Period..

.........................................................................................

..................................................................................... 2-3

.......................................................................................

.......................................................................

.............................................................. 2-3

.............................................................................

Contigur8tion

.......................................................................

................................................................

.................................................. 4-5

Page

V

2-l 2-2 2-2

3-1

3-l 3-2

4-l 4-3 4-4

Communication Between Oscilloscope

5

Output Statements Query Commands and Responses..

Input Statements.. ..................................................................................

Setup Transfers Sending and Receiving ASCII Setups

Sending and Receiving Binary Setups. SRQ and Event Codes Interface Messages Local Lockout

Remote Enable (REN). ...........................................................................

Go To Local (GTL)

My Listen Address and My Talk Addresses

Unlisten (UNL) and Untalk (UNT). ..........................................................

Interface Clear (IFC) Device Clear (DCL).

24X5Al2467 Instrument Interfacing Guide

.................................................................................

.....................................................................................

.......................................................................... 5-5

................................................................................

(LLO)

..............................................................................

................................................................................. 5-7

............................................................................... 5-7

................................................................................

and

Controller

..................................................... 5-2

................................................... 5-4

.................................................

........................................ 5-7

5-1 5-3

5-3 5-5 56

5-6 5-7

5-7 5-8

i

Contwtta

Selected Device Clear (SDC). ................................................................ 5-8

Serial Poll Enable and Disable (SPE and SPD) .................................... 58

Command Handler ................................................................................. 5-8

Service-Request GPIB Commands

Headers ..................................................................................................

Arguments.. ............................................................................................ 5-10

Command Separator.. ............................................................................ 5-l 1

Queries

Abbreviations ......................................................................................... 5-l 1

GPIB Commends

6

................................................................................................... 5-l 1

Message Terminator.. ............................................................................ 5-l 1

Numeric Arguments

Measurement Techniques

Introduction ............................................................................................ 7-1

Trigger Settings..

Measuring Time Intervals on Repetitive Signals.. ................................. 7-2

Measuring Single-Shot Time Intervals .................................................. 7-4

Measuring Peak Voltages.. .................................................................... 7-5

Measuring Trigger Level Programming

Rise and Fall Times ............................................................. 7-6

Pege

Handler ....................................................................... 5-S

................................................................................... 5-10

5-l 0

............................................................................... 5-l 2

.................................................................................... 7-1

Compensation..

Examples.. ....................................................................... 7-10

................................................................

7-10

ii 24X%/2467 Instrument Interfacing Guide

Page

A

Appendix

Programming Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A

Tektronix 4041 Program to Send Commands to the Oscilloscope Tektronix 4041 Program to Calibrate Trigger Levels for Transition

IBM PC/XT/AT Program to Calibrate Trigger Levels

for Transition Time . . . . . . . . . . . . . . . . . . . . . .,.............,.................................. .

HP 98Xx Program to Calibrate Trigger Levels

for Transition Time . . . . . . . . . . . . . . . . . . . . . . . .

Tektronix 4041 Subroutine to Measure

Frequency, Count, and Time

IBM PC/XT/AT Subroutine to Measure Frequency,

Count, and Time

Tektronix 4041 Subroutine to Measure Peak

Voltages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

IBM PC/XT/AT Subroutine to Measure Peak

Voltages. . . . . . . . . . . .

HP 98XX Subroutine to Measure Peak Voltages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B Appendix B

Status and Error Reporting _..........._........... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Appendix C

c

Message Command

Appendix D

D

Sweep Speed Command Considerations . .._._.............................................

. . . . . . . . . . . . . . . . . . . ..*..........................

Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . , . . , , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . A-33

A-l A-l

A-2

A-9 A-18 A-28 A-29 A32

A-85

B-l

C-l

D-l

E Appendix E

GPIB Command

Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

F Appendix F

LLMessage Command Character Translations ._........,............................... F-l

24X5A/2487 Instrument Interfacing Guide

E-l

iii

Tables

Table

Functional Enhancement Options .................................................................. l-l

l-1

5-l Command or Query Byte Counts..

Numeric Argument Format for GPfB Commands

5-2 6-l Vertical Commands 6-2 Horizontal Commands.. 6-3 Trigger Commands..

Delay and Delta Commands.. ........................................................................

6-4 6-5 System Commands

GPIB Command Set for the TV Option.. ....................................................... 6-23

6-6

Counter/Timer/Trigger GPIB Commands ...................................................... 6-24

6-7

Word Recognizer GPIB Commands

6-6

GPIB Command Set for the DMM Option .................................................... 6-29

6-9 6-10 Calibration and Diagnostic Commands..

Delay Time and Delta-Delay Time ................................................................. 7-13

7-1 B-l Status Event and Error Categories

B-2 GPIB Status Codes ........................................................................................

C-l MESsage Command Character Translations..

Sweep Speecl Command Results.. ................................................................ D-2

D-l

GPIB Command Summary.. ........................................................................... E-l

E-l F-l

LLMessage? Query Character Set (Code-Sequenced).

LLMessage Command Character Set .......................................................... F-l

F-2

........................................................................................ 6-1

..................................................................................

.......................................................................................

........................................................................................

................................................................

......................................... 5-l 2

..............................................................

....................................................... 6-33

............................................................... B-2

.............................................. c-2

................................ F-2

Page

5-4

z 6-11 6-13

6-28

B-3

0

24X5Al2467 Instrument Interfacing Guide

Operators Safety Summary

The general safety information in this part of the summary is for both operating and servicing personnel. Specific warnings and cautions will be round throughout the manual where

Terms

In This Manual

CAUTION statements identify conditions or practices that could result in damage to the equipment or other property.

WARNING statements identify conditions or practices that could result in personal injury or loss of life.

As Marked on Equipment

CAUTION indicates a personal injury hazard not immediately applicable as One reads the markings, or a hazard to property, including the equipment itself.

DANGER indicates a personal injury hazard immediately applicable as one reads the marking.

Symbols

In This Manual

they

apply and do

not

appear in this summary

A

As Marked on Equipment

A

24X5A/2467 Instrument interfacing Guide

information is to be found. For maximum input voltage see Table 6-l.

DANGER-High voltage.

Protective ground (earth) terminal.

!

ATTENTION-Refer to manual.

This symbol indicates where applicable cautionary or other

!

V

Operators Safety Summary

Power Source

This product is intended to operate from a power source that does not apply more

than 250 volts rms between the supply conductors or between either supply conductor and ground. A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation.

Grounding the Product

This product is grounded through the grounding conductor of the power cord. To avoid electrical shock, plug the power cord into a properly wired receptacle before connecting to the product input or output terminals. A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation.

Danger Arising From Loss of Ground

Upon loss of the protective-ground connection, all accessible conductive parts (including knobs and controls that may appear to be insulating) can render an electric shock.

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. For detailed information on power cords and connectors see Table 1-l.

Use the Proper Fuse

To avoid fire hazard, use only a fuse of the correct type, voltage rating and current rating as specified in the parts list for your product.

Do Not Operate in Explosive Atmospheres

To avoid explosion, do not operate this product in an explosive atmosphere unless it has been specifically certified for such operation.

Do Not Remove Covers or Panels

To avoid personal injury, do not remove the product covers or panels. Do not operate the product without the covers and panels properly installed.

vi

24X5A/2467 Instrument Interfacing Guide

Introduction

The Tektronix 2445A, 2455A, 2465A, and 2467 Portable Oscilloscopes have raised measurement capability and operator efficiency far above previous standards. These qualities are enhanced by a family of Options. Options are available individually or in

Special Editions which combine them in synergistic packages.

Number

10

09/09

09

01

05

Functional Enhancement Options

Table l-l

Designation

IEEE-488 (GPIB) Interface

Counter-Timer-Trigger

w-v

Word Recognizer (WR

Digital Multimeter

@MM)

TV/Video Analysis System (TV)

Adapts the oscilloscope to measurement

systems. (Included in 2465A DV, 2465A

DM, 2465A CT.)

Measures frequency, period, or total; enhances timing accuracy; delays trigger by event count; triggers on signal combinations. (Included in 2465A DV, 2465A Dfvl, 2465A CT.)

Triggers sweep or counter on 17-bit word. (Included in 2465A DV. 2465A DM, 2465A CT.)

Measures V,. V,,. A*, A,,, resistance,

continuity, temperature, dB. averages, and changes, with 4 112 digits (included in 2465A DV, 2465A DM).

Triggers on selected video lines: clamps

‘back porch.” (Included in 2465A DV.)

Function

24X5A/2467 Instrument Interfacing Guide l-l

This Interfacing Guide shows how to use the 24X5A/2467 Oscilloscopes with Option 10 in a GPIB system. It explains the instruments’ measurement capabilities, how to set them up for GPIB operation, and how to communicate with the

oscilloscopes and their options with a system controller. Consult the instrument operators manual for basic measurement techniques.

If your instrument is configured with at least the GPIB and CTT (Options 10 and 06

or Options 10 and 09), it can measure frequency, period, time interval, peak voltages, rise and fall time, slew rate, duty factor, peak-to-peak voltage, frequency ratio, and other signal parameters automatically. The DMM adds precise measurements of lowspeed signals to the possibilities for automation.

If your tests are not suited to automation, a measurement system can interact with

an operator through the instrument. The controller sets the scope to display a

waveform and the operator positions AV or At cursors to the points of interest. The controller men logs the measurement or compares it to limits. In other applications. the operator adjusts a circuit or device by looking at an automatically displayed waveform. Cursors can indicate test limits or adjustment targets.

1-2

..x-_..- ..__ -..^.._ l.l-

24X5/\/2467 Instrument Interfacing Guide

Measurement Capabilities

and Characteris tics

cursors

For semiautomatic measurements, the cursors aid communication between the system and the operator. An operator can align the cursors with specific waveform features and the controller can assimilate the data. A controller can set the cursors to nominal starting positions, close to the actual measurement or to limit positions within which a waveform should fall.

The cursors give excellent accuracies. They eliminate graticule interpolation and they eliminate CRT geometry errors. Time measurements spanning 4 divisions or more are accurate within -+ 1.25% of reading with X10 MAG off or 2 1.75% with Xl 0 MAG on. Low-frequency voltage measurements spanning 3.2 divisions or more are accurate within + 2.25%. Always use the largest possible display of any

waveform for the best accuracy.

For intervals less than 4 ns, delta-time cursors are more accurate than the

55 ps basic accuracy of counter-based, delta-delay-time measurements.

Frequency and Period

An oscilloscope with the CTT option directly measures frequency or period of the A-trigger signal, but accurate counting requires greater signal amplitudes than stable sweep triggering requires. The highest frequency specified for counting is 150 MHz, even though sweep triggering is specified to much higher frequencies.

Two factors cause these differences. the signal, even though the sweep will trigger on marginal or very-high-frequency signals that the shaping comparator sometimes misses. Second, the shaping circuits driving the sweep and the counter may have slightly different thresholds.

To count the frequency or period of a Channel 1 or Channel 2 signal, use DC

trigger coupling and at least 1.5 divisions peak-to-peak signal amplitude, from

0.5 Hz to 50 MHz; use at least 4 divisions up to 150 MHz. Counting from Channel 3 or Channel 4 requires only half as much display amplitude.

24X5AI2467 Instrument Interfacing Guide 2-l

First, the counter must ‘see” every cycle of

--...- _.____ “,.

MesSUremen! c8p8bitities 8i?d ti8f8CteriStiCS

Time Interval

Automatic time interval measurements depend on the relationship between a waveform and the sweep generators. This relationship is established by the horizontal display, sweep delay, and trigger controls. Instruments equipped with the Counter-Timer-Trigger (Cl-T) measure actual delay time, whether the B Sweep runs immediately after delay or waits until receiving a trigger signal after delay. If the B Sweep is triggered after delay, the measurement automatically tracks varying intervals.

The counter operates with the delayed (B) sweep, in both delay-time and deltadelay-time modes. It counts time-base-clock pulses from the A-Sweep trigger event to the start of the B Sweep. In the delta-delay-time mode the B Sweep displays a pair of events that define the interval of interest and the counter determines the difference between the pair of delay times.

The time resolution you select determines how long you must wait for the instrument to complete a time interval measurement. AUTO resolution gives the

fastest measurement response, as short as 0.5 second. With 10 ps, 100 ps. or 1

ns resolution, response time depends on how long it takes to accumulate 1 ,OOO,OOO or 10,000 or 100 A Triggers, respectively. Higher signal frequencies give higher A-Trigger rates, but the minimum trigger period is

the A SECiOlV setting. Increasing HOLDOFF increases the minimum trigger

period.

about

2 ps plus 12 times

Repetitive Time Intervals

The counter measures each of the two delay-times inherent in the deltadelaytime mode; then it determines the equivalent time between the B-Trigger events by taking the difference between the pair of measured times.

Delta-delay-time mode yields the best possible accuracy for many time measurements. The difference measurement cancels delay differences between the A Trigger and the B Trigger. With delta-time, you can measure very short intervals, down to the resolution limit. However, delta-time measurements require repetitive

signals.

For the best deltadelay-time accuracy, expanded displays of the beginning and

ending of an interval must be visually superimposed. You can disregard superposition of the ends of the interval, with triggered delta-delay-time, if the transition times of the signals are short compared to the accuracy you need.

2-2 24X5A/2467 Instrument Interfacing Guide

Meesurement Cepebilities end Cherecteristics

Non-Repetitive Time Intervals

The CTT also measures non-repetitive signals and isolated intervals, by measuring delay-time. If the A Sweep triggers on one event and the B Sweep triggers on another, the counter records the time between the events. The two events could be the rising and falling edges of a single pulse. Using the delay mode, you can measure pulse widths or propagation delays as short as 70 ns. You can measure single-shot time intervals with lo-ns resolution.

Peak Amplitude

In response to a command from a GPIB system controller, the oscilloscope can measure signal peaks. The A-Trigger circuit compares trigger levels to the peaks.

The trigger levels match the signal peaks within + [3% of peak +3% of peakto-peak +O.l division +(0.5 mV X probe attenuation)]. Peak voltage accuracy is not specified for signals with transition times less than 20 ns. Fortunately, peak voltages of similar signals can be compared more accurately than the specifications indicate they can be measured. Differences between signals with similar waveforms and repetition rates can be accurately determined, even if the signal transitions are

faster than 20 ns.

If the signal period exceeds 20 ms. set SEGiDlV slower than 0.25 times the signal period. With SEC/DIV from 50 ms to 500 ms, the instrument will measure

the peaks of signals with periods up to 200 ms. If SEClDlV is 5 ms or faster, the measurement should take no more than 2 seconds, and usually takes much less. With slower sweeps, to accommodate slower signals, the measurement can take up to 20 seconds.

24X5A/2467 Instrument Interfacing Guide

2-3

Programming Techniques

Self-Contained Programs

The oscilloscopes in this series can satisfy many repetitive test and measurement requirements, without external controllers. They can store as many as 30 setups, with seven-character names, which can be grouped into multiple sequences. The setups in any of the sequences can be recalled by operating a single button on the front panel or by operating an external switch, connected to

the instrument’s rear panel.

With the CTT (Option 09 or 06), these setups can measure frequency, period, time intervals, and slew rate automatically. With some operator interaction you can measure rise and fall time, duty factor, peak voltage, and other signal parameters.

With the GPIB (Qption lo), the 30 setups can be copied from one oscilloscope to

others, using only a GPIB cable, without a controller or other external device. See

EXER 13 and EXER 14 in Section 4. See the instrument Operators manual for

complete instructions.

Easy Programs

With minimal programming, a system controller can augment the oscilloscope with conditional sequences, limit testing, data logging, and extended operator prompting, beyond the seven-character setup names. Test program generators and

executors facilitate this level of programming and relieve the test developer of

writing and debugging code. The test developer sets the instrument manually and

chooses a set of test parameters for each step in a test procedure. The controller

‘learns” the setup and the set of test parameters for future use.

Test program development and execution software from Tektronix includes EZTEK-2400-PC, for the IBM AT/XT/PC and equivalents, and EZ-TEK-2400 and EZTEST, for the Tek 4041 controller. The Tektronix GURU interface package, which adds GPIB controller capability to the IBM AT/XT/PC and equivalents, also includes a test program generator.

If you use a test program generator, you can disregard the tables of commands in this guide. Refer to ‘Setting GPIB System Parameters” to establish compatibility with your controller.

24X5A/2467 Instrument Interfacing Guide 3-1

Progremming Techniquea

Full-PO wer Programs

If you need to automate voltage measurements and indirect time measurements, you can take advantage of the versatility of the instrument command language. Automatic measurements can include rise and fall time, duty factor, peak voltage, and other signal parameters, by programming specific instrument commands.

Even if you use the full power of the instrument command language and the

controller language, most tests and measurements can be set up by operating the

instrument manually, then transferring the setup information to the controller for

future use and possible modification. See the ‘LLSET’?” query and ‘LLSET’ directive described in Table 6-5, System Commands. Sample program segments follow the command tables.

3-2

24X5Al2467 Instrument Interfacing Guide

System Configuration

Setting GPIB System Parameters

To use the oscilloscope with a GPIB controller, system compatibility must be established by setting a few key parameters. Use the oscilloscope front panel controls to select the primary address, message terminator, and talk/listen mode. These selections are accessible through ‘exerciser” routines. GPIB exercisers also can transfer the set of thirty saved setups from one instrument to one or more other instruments, without a system controller.

GP EXER 11 Program GPIB Address GP EXER 12 Program GPIB Message Terminator and Talk/Listen GP EXER 13 Receive-Setups Mode GP EXER 14 Send-Setups Mode

To operate these exercisers:

1. Enter the Diagnostic Monitor mode by pressing and holding both AV and At, then pressing Trigger SLOPE while holding AV and At. The readout will

display ‘DIAGNSTIC. PUSH A/B TRIG TO EXIT,” indicating the Diagnostic Monitor mode.

2. Repeatedly press the upper or lower Trigger MODE button to sequence through the TEST and EXER routine labels and select the one you want to

run.

3. Press the upper Trigger COUPLING button to execute the selected

Exerciser.

4. To exit an exerciser, press the lower Trigger COUPLING button.

5. To return to normal instrument operation, press A/B/TRIG (or, with the available C77, press A/B/MENU).

In the following descriptions, the lines marked with > show what is displayed in

the top row of the readout.

24X5A/2467 Instrument Interfacing Guide 4-l

System Conftgwation

QP EXER 11 Program GPIB Address for Talk and Listen

> GPIB ADDRESS nn

nn = a primary address within 0 to 31. Turn the A control to

select the appropriate address. With address 31, bus data has no

effect on the instrument and is unaffected by the instrument.

The instrument does not have secondary addressing.

GP EXER 12 Program GPIB Message Terminator and Talk/Listen

Press the upper MODE button to select EOI or LF as message terminator.

Press the upper COUPLING button to select TALWLlSTEN or LISTEN operation.

> TERMINATOR EOI MODE TALK LISTEN

The instrument accepts only the EOI bus message as the end of a string of received bytes. The instrument asserts EOI at

the end of a string of transmitted bytes. The instrument can be addressed either as a talker to send settings and readings or as a listener to receive control information.

> TERMINATOR LF MODE TALK LISTEN

The instrument accepts either the EOI bus message or an LF (line feed) character as the end of a string of received bytes. The instrument asserts CR (carriage return) then LF

with EOI at the end of a string of transmitted bytes.

> TERMINATOR EOI MODE LISTEN ONLY

The instrument will not operate as a bus talker. It will receive control information. The listen-only mode allows the instrument to share a GPIB address with another instrument that talks.

> TERMINATOR LF MODE LISTEN ONLY

4-2

24X5A12467 Instrument Interfacing Guide

System Configuration

GP EXER 13 Receive-Setups Mode

> READY TO RECEIVE SETUPS

1. Connect the instrument to another instrument of the same model and with the same options by a GPlB cable. If the instrument is a different model in the following list: 2445A, 2455A, 2465A, 2465ACT, 2465ADM. 2465ADV, and 2467, or one with a different set of options, most setups will be valid, but some will give unpredictable results.

2. Select GP EXER 14 in the other instrument.

> RECEIVING SETUPS

When the transfer is complete, the instrument will exit EXER 13 automatically.

GP EXER 14 Send-Setups Mode

Before executing this exerciser, make sure the instrument is connected to another by a GPIB cable and be sure the other instrument is in the “READY TO RECEIVE SETUPS” state initiated by GP EXER 13.

> SENDING SETUPS

When the transfer is complete, the instrument will exit

EXER 14 automatically.

Instrument Configuration

1. Select a primary address for the oscilloscope.

2. Set the scope address through the diagnostic exerciser.

NOTE

/f you are using an HP controller, the standard l/O port is 7. Add the value of the scope address to 700 and use the result as the device identifier in all calls to the scope.

24X5A/2467 Instrument Interfacing Guide REV SEP 1967 4-3

System Confh7uration

3. Select the message terminator. If you are using an HP controller, the message terminator must be set to LF. For other controllers, use EOI.

4. Select TALK/LISTEN mode, not LISTEN ONLY.

IBM PC/XT/A T Configuration

For IBM computers, using the Tektronix GURU interface or the National

Instruments IEEE-488 interface, do the following.

1. Determine whether you have a PC2 or PCPA interface board. PC2A has a clock. Be sure jumpers and switches are set correctly.

2. If you are using the National Instruments interface package, execute IBSTART, which augments the CONFIG.SYS file on the root drive by

adding a line.

DEVICE=GPIB.COM

If you are using the Tektronix GURU package, be sure the GURU diskette is in the root drive or else copy the CONFIGSYS file on the GURU diskette to the root drive, after backing up the original file.

3. Execute the tBCONF program.

l

In the GPIBO menu, be sure the correct card is selected. DMA should be

1. Set any other configuration parameters as required.

l

Choose and enter a name for the oscilloscope. Use ‘02465” if you are going to use the XTNLEV program.

l

Using the sub-menu of the device name you chose, set the primary

address to the value you selected in step 1 of Instrument Configuration.

l

Save any changes you made and exit IBCONF.

4.

Make sure a copy of the file GPIB.COM exists in the directory your computer boots up from.

5.

“Boot” the system to initialize it for GPIB operation with the defined device

address(

6.

Be sure the logged drive contains a copy of the file BIB.M, part Of the

interface package.

7.

Execute

8.

Load and execute any valid application program. Each application program

BASICA.

must incorporate at least lines 1-6 of the file DECL.BAS, part of the interface package.

4-4 24X5A/2467 Instrument Interfacing Guide

System Configurstion

Program Considerations at Power-on

If you are using the self-programming features or a test program generator, you can disregard the information in this section. At power-on, the instrument restores the setup in effect at power-off or saved setup number 1, depending on the selection made by an extended-function exerciser, described in the Operators manual. The GPIB interface enters the Local State (LOCS).

If service requests were enabled at power-off, the GPIB interface asserts

Service Request (SRQ) at power on. The normal response of a controller to SRQ

is a serial poll, but the instrument will communicate normally on the GPIB whether or not the controller responds to an SRQ. If the controller performs a serial poll, the oscilloscope responds with a status byte of 65 decimal, meaning that the instrument has just powered up.

Some controllers, such as the Tektronix 4051 and 4052 without the 405XA14

GPIB ROM pack, require a program with an SRQ handler. The program should begin by enabling this handler; otherwise, a power-on SRQ will cause the program

to halt and display the error message ‘NO SRQ ON UNIT.” Examples of SRQ

handler routines for both Tektronix 4041 and 405X series controllers are contained in the ‘SRQ and EVENT Codes’ section.

24X5A/2467 Instrument Interfacing Guide 4-5

Communication Between

Oscilloscope and Controller

GPIB controllers use high-level languages such as Pascal, C, and BASIC to define

messages and transfer them to and from the oscilloscope. Statements in these languages usually contain three parts: the input/output keyword (such as ‘PRINT” or

“read”), the GPIB logical unit designator (such as ‘08” or ‘scope”), and a character string or string variable designator (such as ‘CHl COUPLING:DC”) that forms a specific instrument command or response. The following statement in Tektronix 4041 BASIC sets CH 1 coupling to dc, if the instrument has been previously identified as logical unit #8. All program examples are given in Tek 4041 BASIC unless otherwise noted.

220 PRINT #6: "CHl COUPLINGIDC"

You may prefer to assign the oscilloscope GPIB address to a variable and use that variable in I/O statements. This can make the code more understandable and reduce effort and errors when changes are required.

320 Let scope=6

. . .

730 Print

24X5A12467 Instrument Interfacing Guide 5-l

#scope:

“CHl COUPLINGIDC"

Communicetion Between Oscilloscope 8nd Controller

Output Statements

The following examples show output statements in several controller languages. Any instrument command can take the place of “string” in the examples. Each statement assumes a prior configuration and declaration of the GPIB port and the device (oscilloscope) on the bus.

Tek 4041 BASIC:

PRINT #lOI "string"

IBM AT/XT/PC, with Tek GURU GPIB Interface and Microsoft BASIC, where WRT$ is an output string buffer:

IBM AT/XT/PC, with National GPIB/Pascal Interface and Turbo Pascal, where wrl is an output string buffer and cnt is the number of bytes to be sent:

HP 9826A BASIC:

OUTPUT

710: %tring"

Query Commands and Responses

The oscilloscope will transmit measurement or status information after a query command has been sent to the scope. Query commands are formed by immediately following a header with a question mark. The query and input operations can be specified by separate statements. In some controllers, a prompting input statement can perform both functions. For example, the following Tek 4041 statement acquires the channel 1 settings, where set$ has previously been declared an array of 100 characters.

160 Input #lO prompt %Hl? "I sets

The controller addresses the oscilloscope as a listener at primary address #lO then sends ‘CHl?” over the bus. The controller then reassigns the instrument to be a talker and inputs the characters into the target variable (set$). The set$ variable then contains the following information, for example:

CHl VOL:SO.OE-~,VARIO.O.POSIO.O,COU:FIF:

5-2 24X5At2467 Instrument Interfacing Guide

.-.... “_

Communication Between Oscilloscope and Controller

If a query includes an argument to specify a parameter, the response is shortened. For example, if the query ‘CHl? COUPLING” were sent to the oscilloscope, the response returned to the controller could be:

CHl COUrDC:

input Statements

The following examples show input statements in several controller languages.

The instrument response occupies the S$ or rd$ buffer in the examples. Each

statement assumes a prior configuration and declaration of the GPIB port and the

device (oscilloscope) on the bus. Each input must be preceded by a query to

identify the information desired.

Tek 4041 BASIC:

INPUT #lOrSS

IBM AT/XT/PC, with Tek GURU GPIB Interface and Microsoft

BASIC, where WRT$ is an output string buffer:

IBRD (SCOPE%.RDS)

IBM AT/AT/XT/PC, with National GPlBlPascal Interface and Turbo Pascal, where wrt is an output string buffer and cnt is the

number of bytes to be sent:

lbrd(scope.rd,cnt):

HP 9826A BASIC:

INPUT 71033s

Setup Transfers

Only rarely should an oscilloscope setup be defined entirely by the commands in the command tables. Initial setups normally should be copied from a manually operated instrument, then modified if necessary by a few commands. The instrument can transfer setups in tour ways. See the operators manual and the command tables for details,

1. Thirty internally stored setups can be copied directly from one instrument to another, through a GPIB cable, without a controller.

2. The current setup can be transferred to a controller in response to an LLSET? query and returned by an LLSET command. The setup is transmitted compactly, in an eight-bit binary format.

24X5A12467 Instrument Interfacing Guide

5-3

Communication Between Oscilloscope and Conlroller

3. The current setup can be transferred to a controller in response to a SET? query and returned by a SET command. The setup is described fully in ASCII characters, as defined in the command tables.

4. Thirty internally stored setups can be transferred to a GPIB controller, in eight-bit binary format, using the LOADSEQ? query. The setups can be sent to an oscilloscope with the LOADSEQ command.

Table 5-l

Command or Query Byte Counts

Command Maximum 6yte Count Maximum Byte Count

or Query with GPIB Only with All Options

LONGFORM Oif Ofl Off On

LLSET 90 92 154 156

SET

LOADSEQ

588 a45 a42

4043 4843 4043 4643

1303

Use LLSET? and LLSET to avoid wasting time and memory space, if your

controller can handle binary data.

Sending and Receiving ASCII Setups

To save a setup for future use, request a SET? string from the oscilloscope and store it in a string variable. To set the instrument up with the stored parameters, simply send the string back to the instrument.

400 Dim strS 410 Input #a prompt ‘%ETP”:s~~~! Input front

420 Dim atrs to len (strt)! M-dimension

. . .

450 Print m:atrs

5-4 24XW2467

to 1400

! Dimensloa variable

! panel setup into atrs

atr$ to actual

! string

Instrument Interfacing Guide

Communication Between Oscilloscope end Controller

Sending and Receiving Binary Setups

To obtain a Binary front-panel setup from the oscilloscope, send LLSET? and store the response either in a string variable or in a numeric array according to the capability of your controller. If the data is stored as an ASCII character string, the controller must support E-bit ASCII characters or the data will be invalid. The following 4041 example inputs the LLSET? response to a binary variable. To set the instrument up with the stored parameters, simply send the array back to the

instrument.

. . .

400 Dim bind to 200 ! Dimension array variable 410 open #BI“GPIB (PRI=~,EOM=~O~)I” 420 Input #a prompt ‘fSET?“rbin$! Input front

! pane1 setup

450 Dim bin$ to len (binj)! Re-dimension bin$

! to actual array

. . .

460 Print #8rbin$

into bin$

SRQ and Event Codes

The most recent RQS ON or RQS OFF command (see Table 6-5, System Commands) determines whether the instrument will generate the Service Request

(SRQ) message on the GPIB when either an error or a change in status occurs.

The enabling or disabling effect of the RQS command persists through power-off and power-on, so the power-on SRQ also is controlled by the RQS command. The SRQ indicator lights when the scope asserts the message on the bus.

If the controller is configured and programmed appropriately, the SRQ

interrupts the normal flow of the program. To service an interrupt, the controller

performs a Serial Poll. In response, the oscilloscope returns a Status Byte (STB), which reveals the type of event that occurred. It also drops SRQ. If the instrument has another event to report, it reasserts SRQ. The SRQ indicator extinguishes when all events are reported. If the controller does not respond to the SRQ message, the instrument continues to operate and communicate normally, even though the condition that initiated the SRQ may invalidate a measurement.

The operator can generate SRQ and the user-request event (403). The SWRQS ON; command enables or disables SRQ on closure of a switch connected to the rear-panel STEP/AUTO EXT SWITCH connector, if RQS is on. The event is included in the response to serial poll regardless of RQS. If a Tektronix probe with an Identify button is connected to a vertical input, pressing the button with RQS on also generates the SRQ and event 403.

24X5A/2467 Instrument Interfacing Guide

5-5

Communicetion Between Oscilloscope end Controller

To obtain more information about an event, the controller can send an EVENT?

query. The instrument responds with a number which indicates the specific event.

The various status bytes, events codes, and errors are defined in Appendix 6.

This program segment shows how to handle an SRQ, determine the instrument status, and display the Status Byte and the associated event code on the controller screen.

800????? ! Simple SRQ Handler 810 poll atb. dev ! poll bus. store status

820 input #dev prompt

830 print

stb; event ! print stb and event on SCI-*8ll

! byte in “stb”

“event?“:event

Interface Messages

This section describes the effects of GPli3 interface messages received by the oscilloscope from a controller. See ANSI/IEEE Std 488-1978 for detailed descriptions of interface messages and resultant interface states. These messages are encoded as single bits or as single bytes. They may be explicitly generated by the GPIB interface software in the controller or they can be composed in hexadecimal format according to the IEEE Standard. They can NOT be sent as character strings in the manner of instrument commands.

Local Lockout (LLO)

The Local Lockout message (LLO) may be received from the controller at any time, whether the instrument is addressed or not. Once the LLO message has been received, the My Listen Address (MIA) message locks out the front-panel and the Go to Local (GTL) message enables them. The LLO message disables the front-panel controls immediately if the instrument is addressed as a listener when LLO is received. If the program sends the LLO message, it should also send the GTL message to a listener-addressed device when the front panel should be active. The LOCK indicator lights when front-panel operation is suspended.

If the controller sets the Remote Enable (REN) line false or if power is cycled off and on, the effect of the LLO message is cancelled and the instrument controls

operate normally.

5-6 24X5Al2467 Instrument Interfacing Guide

controls

Communicetion Between Oscilloscope end Controller

Remote Enable (REN)

When the Remote Enable (REN) line is true and the instrument receives its listen address (MLA), the oscilloscope can receive data from the bus and the oscilloscope’s REM (remote) indicator lights.

If the REN line goes false, the instrument must receive MLA again before it can receive commands. If a command is in process when REN goes false, it continues to execute.

Go To Local (GTL)

If GTL is received, the instrument must receive MLA again before it can receive

commands. If a command is in process when GTL is received, it continues to execute.

My Listen Address and My Talk Addresses (MLA and MTA)

These messages condition the instrument to receive commands or respond to queries and serial polls, respectively. They are received when the Attention (ATN) line is true and the data on the GPIB is hexadecimal 20 or 40 plus the address defined by GP EXER 11.

Unlisten (UNL) and Untalk (UN T)

These messages, equivalent to talk and listen address decimal 31, cancel the

MLA and MTA messages, respectively.

Interface Clear (IFC)

Receiving this message is equivalent to receiving both the UNL and the UNT

messages.

24X5A/2467 Instrument Interfacing Guide 5-7

Communication Between Oscilloscope and

Controller

Device Clear @CL)

The DCL message initializes communication between the instrument and the controller. In response to DCL, the instrument clears any input and output messages as well as any unexecuted control settings. Any errors and events waiting to be reported are cleared except the power-on event. The SRO message

is cleared unless it is asserted for power-on.

Selected Device Clear (SDC)

This message performs the same function as DCL, only if the instrument has been listen addressed.

Serial Poll Enable and Disable (SPE and SPD)

The Serial Poll Enable (SPE) message causes the instrument to transmit its serial-poll status byte when it is talk-addressed. The Serial Poll Disable (SPD) message returns the instrument to normal operation.

Command Handler

A command handler establishes communication between the controller and oscilloscope, sends commands and queries to the oscilloscope, receives responses from the oscilloscope, and processes the responses as required. The following outline indicates a general sequence of command-handling functions.

1. Initialize the controller.

2. Disable the service-request handler until the program is ready to handle them.

3. Get the GPIB address of the oscilloscope.

4. Enable the service-request handler.

5. Send a command to the oscilloscope.

6. Check for a response from the oscilloscope.

7. Process any response as desired.

6 Repeat steps 5 through 7 as desired.

5-8

24X5A/2467 Instrument Interfacing Guide

Communication Between Oscilloscope and Controller

Service-Request Handler

A service-request handler processes the interrupts generated by the SRQ message on the GPIB. For example, when cursors have bean placed on points of interest on a waveform, an operator can press a switch connected to the rear panel which can cause the oscilloscope to assert SRQ. In response the controller program can verify that the switch closure caused the interrupt, then query the cursor measurement and compare the measured value to preset limits.

Events at which the oscilloscope asserts SRQ are identified in Appendix 8.

Some controllers can ignore service requests and others require a programmed response to SRQ. Most controllers ignore service requests until SRQ interrupts are

explicitly enabled.

An SRQ handler needs an interrupt-enabling statement (eg. ON SRQ statement-label) near the beginning of the program and a serial-poll subroutine with that label. The ON SRQ statement directs program control to the serial-poll subroutine whenever an SRQ interrupt occurs. The instrument maintains the identity of an event that generates an SRQ until a serial poll is executed by the interrupt-service subroutine.

The following general steps handle service requests from the oscilloscope:

1. Perform a serial poll to determine which device on the bus is requesting service. The serial poll clears an SRQ generated by the oscilloscope, unless more than one event has been identified.

2. Send an EVENT? query to the oscilloscope requesting service.

3. If the EVENT? query response is not zero, perform the appropriate response to the event.

4. Return to the main program.

24X5A12467 Instrument Interfacing Guide 5-9

Communlcetion Between Oscilloscope end Controller

GPB Commands

The GPIB commands set instrument operating states, query the operating states, and query the results of measurements. These commands are specified in mnemonics that are related to function names or front-panel control names. Commands follow the conventions established in the Tektronix Codes and Formats Standard.

Command messages consist of headers, arguments, separators, and message

terminators.

A command contains at least a header. A few commands are fully specified by

a header. For example:

INIT

Arguments

Most commands require arguments after the headers. An argument must be

separated from its header by at least one space.

DELAY l.OE03 HMODE XY

Some arguments consist of primary and secondary arguments. Primary and

secondary arguments must be separated by a colon.

CHl VOLTS:6 ATRIGGER MODE:AUTOLEVEL

Some headers allow multiple arguments, which must be separated by commas.

A colon still separates primary and secondary arguments.

CHl VOLTS:5,COUPLING:DC,POSlTlON:1.2 VMODE CHl:OFF,CH2:ON,ADD:ON

5-10

_ ..” .“I_ _..._

24X5A/2467 Instrument Interfacing Guide

Communication Between Oscilloscope and Controller

Command Separator

Multiple commands can be combined in one message by separating the

individual commands with semicolons.

CHl VOLTS:5,COUPLING:DC;VMODE ADD:ON

Queries

In a query, the question mark must immediately follow the header, with no

space.

DVOLTS? ATRIGGER? COUPLING

Message Terminator

Messages can be terminated with either EOt or LF, depending on the system

controller. The GPIB interface can be set to accept either terminator, using EXER

12, as previously explained. With EOI selected, a data byte received with EOI

asserted is recognized as the end of an input message. The instrument also asserts EOI concurrently with the last byte of an output message. With the LF setting, either an LF character or any data byte received with EOI asserted is

recognized as the end of an input message. With the LF selection, the instrument transmits a Carriage Return character followed by Line Feed (LF) with EOI asserted to terminate an output message.

Abbreviations

The defined words in headers and arguments can be entered at full length or shortened to reduce typing and bus traffic. The command tables show the essential characters of headers and arguments in upper-case characters and optional characters in lowercase. The instrument accepts either upper case or lower case characters. For example, any of the following commands are acceptable.

VMO? vmadt vmode invert VMODE INVE

24X5A/2467 Instrument Interfacing Guide 5-11

Commuflk8tion Between Osciltoscope and Controlier

Numeric Arguments

The following table depicts the formats for numeric arguments in the GPIB

command set. Both signed and unsigned numbers

numbers are interpreted

as

positive.

are

accepted but unsigned

The symbol tnrx> indicates that

only one specific format is permitted, it is represented by nrl , nr2, or nr3.

any

of the three formats is allowed. When

fable 5-2

Numeric Argument Format for GPIB Commandr

Numeric

Argument

tnrx>

bol Number Format

SYl

<ml>

tnr2> Explicit decimal point <nr3> Floating point in

Integers

scientific notation

+1,z

-3.2, +5.1, 1.2

+l.E-2, l.OE+2, l.E-2, O.O2E+3

Examples

-1, -10

5-12 24X5Al2467 Instrument Interfacing Guide

GPIB Commands

NOTE

Some commands are valid on/y with 2445A, 2455A, or 2467. These are indica ted by “(A) ” in the descriptions. The other commands are valid with the earlier 2445 and 2465

Table 6-1

Vertical Commands

CHl

CHl?

Header

Argument

Coupling:

POSition:

VARiable:

VOLls:

Coupling

POSition VARiable VOLts

Argument

AC DC FlFty GND

tnrx>

Description

Selects Channel 1 vertical parameters. Sets input coupling.

Sets position to tnrx> divisions from center. Range extends -+ 11 divisions.

Sets VoltslDiv Var to the approximate value of <nrx> in the range from 0 to

10. At tnrx> = 0, Vofts/Div is

calibrated. Sets Volts/Div deflection factor to the

value of <nrx>. If tnrx> is not a valid. calibrated VoltsiDiv for the installed probe, the next higher calibrated Volts/Div or the highest VoltslDiv is used and an error event is generated.

Query returns CHl VOL: tnr3>, VAR:<nrl>. POS:tnr3>. COU: <argument>;.

Response: CR1 COU:targument>;. Response: CHl POS:tnR or nr3>;. Response: CHl VAR: tnrl or nr2>;.

Response: CHl VOL:tnr2 or nr3>;.

PRObe

24X5A12467 instrument Interfacing Guide

CHl? PROBE must be queried explicitly; it is not included in the CHl? query response. The response string indicates the probe attenuation coding: Xl, X10, Xl00 or X1000.

6-1

GPIB Commands

Table 6-1 (cant)

Header

CH2

CH2?

CH3

CH3?

CH4 CH4?

VMOde

Argument

INVert:

INVert

BWLimit:

cl-lop:

CHI :

CH2:

Argument

ON

OFF

ON

OFF ON OFF

ON OFF

Description

Same as CHl plus INVert: argument. Turns Channel 2 inversion on or off.

This command has the same effect as VMOde INVert: <argument>. Same as Cl-H, except query also returns INV:<argument>. where argument is either ON or OFF.

Same as CHl , except Coupling and VARiable arguments are invalid and POSition range is + 4 divisions.

Same as CH3.

Selects channels to be displayed, Chop or Alternate channel-multiplexing mode, limited or full vertical bandwidth, and Channel 2 inversion. When all channels

are

off, Channel 1 is

Sets state of bandwidth limit.

Selects Chop or Alternate multiplexing. Default is Chop (ON).

Turns Channel 1 on or off.

Turns Channel 2 on or off.

displayed.

CH3:

CH4:

ADD:

INVet-t:

6-2 REV OCT 1986 24X5A/2467 Instrument Interfacing Guide

ON

OFF

ON OFF

ON Selects normal or inverted Channel 2 OFF

Turns Channel 3 on or off.

Turns Channel 4 on or off.

Turns display of sum of Channel 1 plus Channel 2 on or off.

display. Default is INV (ON).

Table 6-l (cant)

Header Argument Argument Description

GPl8 Commands

CHOp CHl CH2 CH3 CH4 ADD INVert BWLimit

Query returns current state of the vertical display: VMO CHl:targument>, CH2: <argument>. CH3: <argument>, CH4: <argument>, ADD:targument>, BWL: <argument>, INV: <argument>, CHO: <argument>.

24X5A/2467 Instrument Interfacing Guide

REV OCT 1986 6-3

GPIB Commands

Table 6-2

Horizontal Commands

Header

HORizontal

Argument

ASEcdiv:

BSEcdiv:

MAGnify:

POSition: <nrx>

Argument

tnrx>

ON

OFF

Description

Selects Horizontal display parameters.

Selects A-Sweep speed in seconds per division. Range for the 2465A and 2467 is from 5E-9 to 1.5. Range for the 2445A and 2455A is from 1 OE-9 to 1.5. If the selected speed is faster than the current B Sweep, B-SeclDiv is set equal to A-Sec/Div. The effects of

MAGnify: are independent of

ASEcdiv:.

Selects B-Sweep speed in seconds per division. Range for the 2465A and 2467 is from 5E-9 to 0.15. Range for the 2445A and 2455A is from lOE-9 to 0.15. B-

Sec/Div is updated whether B Sweep is active or not. If the

selected B-Sec/Div is slower than the current A-SeciDiv, A-SeclDiv is set equal to B-SeciDiv. The effects of MAGnify: are independent of

BSEcdiv:.

Turns Xl 0 sweep magnification on or off.

Sets the starting position of the sweep in divisions from the left

edge of the screen over the range

+ 5.46 divisions.

6-4

TRACEsep:

REV SEP 1987 24X5A/2467 Instrument Interfacing Guide

tnrxz

Offsets B Sweep from A Sweep or b-B Sweep from the B Sweep with the reference delay by the indicated amount, in the approximate range from 0 to -4 divisions.

Table 6-2 (cant)

GPIB Commnnds

Header

HORizontal?

HMOde

HMOde?

Argument

ASEcdiv BSEcdiv MAGnify

POSition

TRACEsep

ALTernate

ASWeep

BSWaep

XY

Argument

Description

Query returns the horizontal selections: HOR ASE: tnrx>, BSE:<nrS>, MAG:targument>. POS:tnrS>, TRACE:tnr2>;. String

is either ON or OFF.

Selects Horizontal display mode.

Choices are mutually exclusive.

Selects both A Sweep and B Sweep for display. This is

equivalent to pulling the SEC/DIV

knob out. Selects only the A Sweep for

display.

Selects only B Sweep for display.

If A-SeclDiv and B-SeclDiv are equal, then a settings conflict error is generated.

Selects XY mode, where Channel

1 drives the horizontal display. Query returns HMO string;, where

the string represents one of the possible Horizontal display modes.

24X5AI2467 Instrument Interfacing Guide

6-5

GPll3 Commends

Table 6-3

Trigger Commands

Header

ATRigger

MODe:

Source:

:

Coupling:

Argument

-EVeI:

Argument Description

Selects A-Trigger parameters.

AUTOBaseline AUTOLevel NORmal SGLseq

Cl-f1 CH2 CH3 CH4 LlNe VERtical

AC DC HFRej LFRej NOlserej

FLDl

CLD2 ALTernate LINES

<nrx>

Selects Mode from the list of arguments. (AUTOBaseline is

equivalent to AUTO.)

Selects Source from the argument

list.

Selects Coupling from the argument list. (Use DC for most applications.)

Only with the available TV option,

selects TV trigger mode.

Sets Trigger Level in volts with rertical channel sources or in dimensionless units with LINE source. The numeric argument is stored as a target value. Trigger eve1 is set at the target value or at I limit value defined by the trigger ;ource. The limits are + 18 times

he VoltslDiv setting for CH 1 and :H 2, f 9 times the Volts/Div jetting for CH 3 and CH 4. and k 10 for LINE. A level query eturns the value of the current

arqet

6-6 REV SEP 1967 24X5Al2467 Instrument Interfacing Guide

Table 6-3 (cant)

Header

ATRigger?

Argument

INIt

SLOpe:

BENdsa:

HOLdoff:

BENdsa

Coupling

HOLdoff LEVel

MODe SLOpe SOUrce

Argumenr

MINUS PLUS

ON OFF

<nrx >

Description

Measures signal peaks at the ATrigger source and sets trigger level at the midpoint between peaks. (A)

Selects Slope 01 the A-Trigger

signal.

Sets the B ENDS A mode ON or

OFF.

Sets

Holdoff to the value of

tnrx> in the arbitrary range from 0 to 10, with 0 representing minimum (normal) holdoff.

Query returns ATR BEN:string, COU:string, HOL:string,

LEV:tnrP>, MOD:string, SLO:string. SOU:string.

Arguments MAX, MINI, READY, and TRIGD must be requested explicitly, e.g. ATR? MINI,MAX.

MAXimum

24XSA/2467 Instrument Interfacing Guide

Query-only returns ATR MAX:cnrx>;. The value of

<nrx> represents the most positive peak voltage, measured in volts, at the A-Trigger source at the most recent operation of the INlT@50% button with the A Trigger or in response to the most recent ATRigger INIt command or the most recent Auto Level acquisition or the most recant ATRigger MODe AUTOLevel command. Normally, the ATRigger

INlt50 command should be sent just prior to

MAXimum auerv.

REV OCT 1966

an

ATRigger?

6-7

GPIB Commands

Header Argument

MINImum

READY

TRIGD

BTRigger

MODe:

Table 6-3

Argument

RUN TRIGGERAble

DRTRigger

(cant)

Description

Query-only returns ATR MINI:tnrx>;. The value of

<nrx> represents the most negative peak voltage, measured in volts, under the same conditions as ATRigger? MAXimum.

Query-only returns ATR

READY:string;. String is ON if the

single-sequence READY indicator is ON. Otherwise, string is OFF.

Query-only returns ATR TRIGD:string;. String is ON if TRIG’D indicator is illuminated. Otherwise, string is OFF.

Selects B-Trigger parameters.

Selects B-Trigger Mode.

Only with the available CTT,

conditions the instrument to direct front-panel Slope and Level controls to the B-Trigger

associated with the A REF delay. This command forces Delta

ModeTime on unless Delta

ModePertime or Delta

ModeCperfime is on. If Delta

MO& Cpertime is on, the command forces a change to Delta

ModePertime. (A)

DTRlgger

6-6 24X5A12467 Instrument Interfacing Guide

Only with the available ClT, conditions the instrument to direct front-panel Slope and Level controls to the B-Trigger associated with the A delay. This command forces Delta Mode:Time on unless Delta Mode:Pertime or Delta Mode:Cpertime is on. If Delta Mode Cpertirne is on, the command forces a change to Delta Mode:Pertime. (A)

”

Table 6-3 (cant)

G/W Commands

Header Argument

SOUroe:

Coupling:

LEVel:

Argument

ALTSlope

CHl CH2 CH3 CH4 VERtical

AC DC HFReJ LFRej NOlserej

<nrx>

Description

Only with the available C‘TT, included only for compatibility with

earlier instruments, and not

recommended for new applications; conditions the instrument to direct front-panel

Slope and Level controls to the BTrigger associated with both A delays, maintaining common levels and opposite slopes. This command forces Delta Mode:Time on unless Delta Mode: Pertime or

Delta Mode:Cpertime is on. If

Delta Mode Cpertime is on, the command forces a change to Delta

Mode:Pertime. (A)

Selects B-Trigger Source.

Selects B-Trigger Coupling. (Use DC for most applications.)

Sets Trigger Level in volts. The

numeric argument is stored as a target value. Trigger level is set at the target value or at a limit value defined by the trigger source. The limits are _+ 18 times the Volts/Div setting for CH 1 and CH 2 and +9

times the VoltslDiv setting for CH 3 and CH 4. A level query returns the value of the current target.

24X5A12467 Instrument Interfacing Guide

Measures signal peaks at the B-

Trigger source and sets trigger level at the midpoint between peaks. (A)

8-9

GPIB Commends

Table 6-3 (cant)

Header

BTRigger?

SLOpe:

DLEVel:

DSLope:

Coupling LEVel MODe SLOpe SOUrce

DLEVel

I

DSLOpe

-

Argument

MINUS PLUS

tnrx>

MINUS PLUS

Description

Selects Slope of the B-Trigger signal.

Only with the available ClT, sets

trigger level for the B Sweep controlled by the A delay setting, in the same manner as LEVel sets

trigger level for all other B-Trigger functions. (A)

Only with the available ClT, selects trigger slope for the B Sweep controlled by the A delay setting, in the same manner as SLOpe sets slope for all other BTrigger functions. (A)

Query returns ETR MOD:string, COU:string, SLO:string, SOU:string, LEV:<nrx>;.

BTRigger? query response only with the available CTT: BTR MOD: string, DSL:string, DLEV: <nrx>, COU: string, SLO:string, SOU:string, LEV:<nrx>;. (A)

610 24X5Al2467 Instrument Interfacing Guide

Table 6-4

Delay and Delia Commands

GPIB Commands

Header Argument

DELAY <nrx>

DELAY?

DELTa

MODe:

Argument

OFF CPERTime

CTlMe

Description

Sets sweep delay to tnrx> divisions in the range from -0.05 to 9.95. This command has the same effect as DTIME REF:

tnrx>. The value of -0.05 assures that the A-Trigger event is visible on the B Sweep.

Query returns the current delay

setting in divisions: DELA

tnr2>;. This response is not

included in a SET? query but the

DTIME REF: tnrx> response to the query contains the equivalent information.

Sets Delta-display parameters. Selects or cancels a Delta mode.

Activates l/At cursors with ASweep or B-Sweep display. With ALT horizontal display, the

command produces an error

response. (A) Activates A.t cursors with A-Sweep

or B-Sweep display. With ALT horizontal display, the command produces an error response. (A)

PERtime

TlMe

24X5Al2467 lntrument Interfacing Guide 6-11

Activates l/At cursors with ASweep display; activates 1 /delta-

delay-time with Alternate or B-

Sweep horizontal display.

Activates At cursors with A-Sweep display; activates delta-delay-time

with Alternate or B-Sweep horizontal display.

GPI6 Commands

Table 6-4 (conl)

H88d8r

DELTa?

DTlme

DTlme?

Argument

TRACKing:

MODe TRACKing

REFerence

DELTa:

REFerence

DELTa

Argument

vous

ON OFF

tnrx>

tnrxb

D8aCriptiOn

Activates AV cursors.

Selects Tracking or Independent A REF control mode. Default is

Tracking (ON).

Cluery returns DELT

MOD:string.TAACK:string;.

Sets reference delay, At cursor, or

l/At cursor tnrx> divisions from A-Sweep start or left edge of the display, in the range from - 0.05 to 9.95. If Tracking is on, the delta

delay or cursor moves as required

to maintain its distance from the

reference, within the -9.05 to

9.95 range.

Sets delta delay, At cursor, or l/At

cursor <nrx> divisions from the reference delay or cursdr. The sum of the reference setting plus the delta setting must be within -0.05 to 9.95 divisions.

Query returns the Delta Time settings in divisions: OTI REF:tnr2>, OELT:tnr2>;.

TOELta?

6-12 24X5A/2467 lntrument Interfacing Guide

Query returns the delta time setting in seconds, hertz, percent, or degrees: < nr3> ;. No ‘TOELTA’ header is returned so high-level input drivers can

process

the response. NOTE: if the query follows a MESSAGE command, a DELTA MODE: <argument> ; command nust be given again to restore the delta reading. (A)

Table 6-4 (cant)

GPIB Commsnds

Header

DVOlts

DVOlts?

VDELta?

Argument

REFerence:

DELTa:

REFerence DELTa

Argument

<nrx>

Description

Sets the reference cursor tnrx> divisions from the center of the display, within the +4.O range. If

Tracking is on, the delta delay or

cursor moves as required to maintain its distance from the reference, within the + 4.0 range.

Sets the delta cursor tnrx> divisions from the reference cursor. The sum of the reference setting plus the delta setting must be within

Query returns the delta volts settings in divisions: DVO REF:tnrP>,DELT:tnr2>;.

Query returns the delta volts setting in volts, or percent: tnrx>;. No ‘VDELTA” header is returned so high-level input drivers can process the response. NOTE: If the query follows a MESSAGE command. a DELTA MODE:VOLTS; command must be given again to restore the delta reading. (A)

Table 6-5

System Commands

Header

BA Lance

ERRor?

24X5A/2467 Instrument Interfacing Guide

Argument Argument Description

Initiates the vertical DC Balance procedure. The instrument initializes after BALANCE (see INIt).

Query returns ERR <nrl>;. Response is equivalent to EVEnt? query. Command is included for compatibility with earlier instruments.

6-13

GPIB Commands

Table 6-5 (cant)

Header

EVEnt?

ID?

Argument Argument

Description

Query returns EVE <nrl>;. The value of tnrl> is the most severe of the current errors. Errors are prioritized into three levels, but only the most maintained for each level. If no error is pending, 0 is returned.

Event codes are listed in Tables B-l and B-2.

Query returns ID TEK/model,VBl .l .SYS:FVx.

BB:FVy, [string:FVtnrl >,] GPIB:,FVz;. The word model stands in place of the strings 2445A, 2455A, 2465A, The characters x, y, and z stand in place of the firmware version numbers of the oscilloscope. Buffer board, and GPIB option, respectively. The section in brackets is repeated for each installed option, including TV and CTT. String V61 .l indicates that the GPIB interface is compatibfe with the VEtl .l version of the Tektronix Codes and Formats standard.

recent error

or 2467.

iS

INlt

6-14 24X5A:2467 InstrumeM Interfacing Guide

Sets the instrument and all options

except the GPIB to an initialized

state equivalent to cycling power

off and on. The GPIB system-

command states (OPC. RQS,

WARning, and LONgform) are not

nitialized. (RQS is not changed by

oower-downlpower-up.) This

:ommand should be the final or

3nly command in a message.

Mditional commands in the same

message give unpredictable

results.

Table 6-5 (cant)

dPlf3

Commends

Header Argument Argument

LLMessage %<byte>tbyte>...

LLMessage?

LLSet % <byte> <byte>...,

Description

Sends binary of the CRT readout. The displays the block of binary data according to the codes in Tables

14 and 15. The first pair of bytes represent the number of characters. The last byte is the two’s complement of the least significant byte of the sum of the character codes.

Query returns the contents of the top line of the CRT readout in a binary block of data, in the form:

LLM %<byte> <byte> . .

<byte>;. The first two bytes followlng the % character are a

16-bit count of the bytes

follow. according to Tables

not ASCII. The last byte of the block is the two’s complement of the least significant byte of the sum of data bytes. (See MESsage? for ASCII coding of the readout.)

Returns a previously acquired

setup

Level binary Setup data generated only by a LLSet? query.

data to the

top line

readout

that

The display is encoded

to the instrument. The Low

14 and 15,

can be

24X5A/2467 Instrument Interfacing Guide 6-l 5

GPIt9 Commands

Table 6-5 (cant)

Header

LLSet?

MESsage

Argument

‘string”

Argument

Description

I-

Query response is a block of binary data representing the instrument setup in the form:

LLSET %<byte><byte>. %tbyte> <byte>;. The block of data comprises a sub-block for each installed option. Each sub-

block begins with a % character followed by two bytes which are a

16-bil count of the bytes that follow. The last two bytes of each sub-block are the two’s complement of the least significant byte of the sum of data bytes, followed by a comma, except that the final block is followed by a

semicolon.

NOTE

The L LSET? query behaves unpredictably if the controller recognizes the LF character as the end of a message.

Displays up lo 32 mostly-ASCIIcoded characters lo the top row of the readout. The string must be enclosed in quotes and may exceed 32 characters because of character translations. The display is filled with blanks after the specified characters. If the string specifies more than 32 display characters, the command is ignored except for an error

*esponse. Table C-l lists the

:haracter set and codes.

6-16

24X5A12467 Instrument Interfacing Guide

Table 6-5 (cont)

OPll3 Commands

Header

MESsage?

OPC

Argument

ON OFF

Argument

Description

NOTE

Before a TDEL TA ? or VDEL TA ? query following a MESSAGE command, a DELTA MODE:targument>; command

must

be given

to

restore

the d&a

reading.

Query returns an ASCII representation of the top line of the display: MES ‘string”;. The string may exceed 32 characters due to character translations.

Enables the instrument to assert SRQ as an * Operation Complets indication after certain diagnostic and option commands. OPC initializes to OFF at power-up.

Only with the available CTT, OPC

enables Event 778 at CTT

measurement completion and, if RQS is ON, OPC enables SRQ at CTT measurement completion. Reading the event code by an EVENT? query clears the event and the SRQ. The event and SRQ

remain clear until the CTT measurement has been read by the appropriate query and a new

measurement is complete.

OPC?

24X5Al2467 Instrument Interfacing Guide 6-l 7

Query returns either OPC ON; or OPC OFF;.

-.---.

t?PlB Commends

Table 6-5 (cant)

Header

READOut

READOut?

RQS

RQS?

Argument

ON OFF

ON

OFF

Argument

Description

Turns the CRT SCALE FACTORS

readout ON or OFF.

Query returns READ0 string;. String is either ON or OFF, indicating the state of the Scale

Factors readout.

Enables the instrument to assert SRQ on detection of specific events, including error conditions. The power-on SRQ depends on the most recent RQS ON/OFF before power-off. (Note that this

command is distinct from the RQS

message on the GPIB. which is one bit in the serial poll response.)

Query return either RQS ON; or RQS OFF;.

6-16

.,----- .”

24X%/2467 Instrument Interfacing Guide

Table 6-5 (cant)

GPIB System Commands

Header

SETtings?

LONgform

LONgform?

WARning

Argument

ON OFF

Argument Description

Query returns an ASCII string of commands tables that represent the current instrument setup. The string contains all required headers and if it is returned to the instrument, it should not be preceded by SETtings or any other header.

LLSet? and LLSet should be used to acquire and restore complete instrument settings to save time and memory space.

The SETtings? query may give inconsistent results with SEC/D/V

VARiable. If the variable is manually set for an A Sweep slower than the next slower speed settable by the SEC/DIV switch,

the SETtings? query will attach the

variable to the B Sweep, and fhe A Sweep will be shown at the next slower speed selectable by the switch.

Enables queries to respond with the full length versions of

commands. When LONgform is

OFF, the shortest acceptable version of commands are used in

query responses. Default

argument is OFF. Query returns either LONGFORM

ON; or LONG OFF;.

as

defined in these

NOTE

WARning?

24X5Al2467 Instrument Interfacing Guide

Enables SRO assertion on

detection Warning initializes to ON at power-up.

Query returns either WARN ON; or WARN OFF;.

of a

potential error.

6-19

System Commands

Table 6-5 (cant)

Header

SAVe <nrx>[:STEP][:‘string”] SAVe tnrxr[:BEGIN][:‘string”] SAVe tnrx>[:END][:‘string”]

RECall <nrx> [:SEQ]

Argument

Description

Saves the current setup as setup tnrx>, in the range from 1

through 30. The optional STEP,

BEGIN, and END arguments

define attributes for sequential recall operation. BEGIN and END define sequence looping boundaries. The STEP argument is assumed if neither BEGIN nor END are given. The optional “string” with up to 7 characters must be delimited by quotes. The string defines a name for the setup. If no name is given in the

command, the previous name of

the setup tnrx> is retained, except that the name ‘NOTSET” will change to ‘SET.” (A)

NOTE

The string can include any of the

characters, A..Z, 0. .9, and the

following punctuation marks.

. : , ? t - I < > %

Lower case letters are converted

to upper case. The space character is converted to a pericd, unless it is not the first character in a name and no other non-space characters follow it. The following punctuation characters are translated to lower case English characters or to Greek characters.

& to k, to m, ( to n. ! to p, = to s, ] to t, # to lower case mu (micro), [ to upper case omega (ohms)

Sets the instrument to saved setup <nrx>, in the 1 to 30 ‘ange. and initiates the Sequence mode if the argument string ‘:SEQ” is included or cancels the Sequence mode if the argument is not included. In Sequence mode, the front-panel STEP/AUTO Jutton selects following setups. (A)

6-20 24X5A/2467 Instrument Interfacing Guide

Table 6-5 (cant)

System Commands

Header Argument

RECall NEXT

LOAdseq

LOAdseq?

AUTOSetup

SWRQS

% <binary data>, . . .

Argument

Description

In Sequence mode only, selects the next higher numbered setup saved in the instrument, or the

previous setup with the BEGIN attribute if the current setup has the END attribute. RECall NEXT is invalid after RECall tnrx> without the ‘:SEQ” colon and argument. (A)

Loads 30 setups into instrument memory which can then be recalled as desired. The binary

data is defined only by the

LOAdseq? query. (A) Query returns 4719 to 4723 bytes

of binary setup data which is valid to send with a LOAdseq command. (A)

NOTE

The LOADSEO? query behaves

unpredictably if the controller recognizes the LF character as the end of a message.

Initiates an automatic setup of scale factors, trigger, and intensity.

IAl Enables or disables a user-request

Went (403) on closure of a switch connected to the rear-panel STEP/AUTO EXT SWITCH connector. An SRQ will be generated if RQS is on (see RQS command). The event is included

n the response to serial poll

,egardless of RQS. (A)

24X5A12467 Instrument Interfacing Guide

6-21

GPIB Commands

Table 6-5 (cant)

Header

INTEnsity

INTEnsity?

HRSon?

CYCles?

Argument

SWEep:

READOut:

RESTore

SWEep READOut

Argument

<nrx>

tnrx>

Description

Sets trace intensity to dimensionless value of tnrx> in the 0 to 255 range. (A)

Sets readout intensity to tnrx>

in the 0 to 255 range. (A)

Only in the 2467, restores trace and readout intensities to previously set values, in the event intensities may have been automatically reduced for CRT protection.

Query returns INTE SWE:tnrl>,READO:<nrl>;.

(4 Guery-only returns HRS tnrl > ;.

The value of tnrl > is the approximate number of hours of Instrument operation. (A)

Query-onfy returns CYC tnrl r ;. The value of <nrl> is the number of times power has been sycled off and on. (A)

6-22

24X5A/2467 Instrument Interfacing Guide

Table 6-6

GPIB Command get for the TV Option

GPIB Conmandr

Header

TVClamp ON

TVClamp?

TVLine tnrx>

TVLine?

LCNTStart PREfld

LCNTStart?

Argument

OFF

ATFld

Argument

Description

Selects AC and TV (back-porch)

Clamp input coupling for CH 2.

If the TV (back-porch) Clamp is active, CH 2 input coupling changes to AC and the N (backporch) clamp is turned off. Otherwise, the CH 2 input coupling

does not change.

Query returns either NC ON or

TVC OFF.

Selects N line number <nrx> for

the A Trigger.

Query returns NL tnrl>;. The value of tnoo is the selected line number.

Selects line count beginning 3 lines

before field-sync pulse (Format 2).

Selects line count beginning at

field-sync pulse (Format 1).

Query returns tine 1 definition: either LCNTS PRE; or LCNTS ATF;.

LCNTReset FlOnly

BOTh

LCNTReset?

24MAl2467 Instrument Interfacing

Selects line count reset only on tield 1 (Format 2).

Selects line count reset on both field 1 and

Query returns Line count reset status: either LCNTR FlO; or LCNTR BOT;.

field 2

(Format 1).

Guide 623

GPlB Commnnds

NOTE

C77 measuremenk are requested with the CTSend? query command. DELAY?

and DTlme? 9ueries return delay and delta settings, not measurements.

Table 6-7

Counter/Timer/Trigger GPIB Commands

Header

CTRdy?

CTSend?

Argument

IMMediate

WAlt

Argument Description

Query returns CTR 1; if a CTT measurement is available or CTR

0; if not. If no measurement function is active, or if a measurement function is suspended because another option

is using the display, an optionnot-in-correct-mode error is generated.

Command requests the result of any of the following measurements: frequency, period, totalize. delay-time, deltadelaytime, or 1 /delta-delay-time. The measurement is returned in format

tnr3>. The ‘?’ following CTSend

has no effect and is optional. If the measurement is invalid, one of the following error codes is returned in place of the measurement:

1 .OE +99 for missing B trigger.

1 .OE + 98 for missing A trigger.

6-24

1 .OE +97 when the time interval in l/At mode is less than 1% of full scale.

1 .OE+96 for Totalize mode Dverflow.

24X5Al2467 Instrument Interfacing Guide

Table 6-7 (cant)

GPlB Commands

Header

CTSend?

(cant)

COUNt

-I-

Argument Argument

CTT Setup Commands

EVEnt:

ATRigger WREcognizer

Description

If no measurement function is

active, or if a measurement function is suspended because another option is using the display, an option-not-in-correct-mode error is generated.

A measurement is sent only once then cleared. A new measurement must be completed before another value will be sent.

CTSend with no argument or the WAlt argument conditions the instrument to send no response

until the measurement is complete. The IMMediate argument conditions the instrument lo send

a null message (talked with nothing to say) if the measurement is not complete.

Configures the Count function.

MODe:

COU Nt?

Cl-f

24X5A/2467 Instrument Interfacing Guide REV OCT 1986 6-2.5

EVEnt MODe

COUNt

DBEvents LTRigger OFF

FREquency TOTal PERlod

If the Word Reccgnizer Option is not installed and If EVEnt:WRE is received, an option-not-installed error is generated.

Query returns COUN MOD:string,

EVE:string;. or COUN arg:string; if an argument is given in the query.

Selects or cancels a CTT function. Selecting any function cancels any other selected function and sets B-Trigger mode to Run AfI Dly.

GPIB Commands

Table 6-7 (cant)

Header

Cl-r?

DBEvents

DBEvents?

Argument

RESET

COUNt:

EVEnt:

STArt:

SWEep:

30UNt EVEnt STArt SWEep

Argument

CTT RESET resets any count or time measurement currently in progress, including delay and delta time.

Query returns ClT string;. The

‘string” names the current CTT function.

<nrl>

BTRigger

WREwgnirer

ATRigger WREcognizer

ASWeep Selecting SWEep:BSWeep sets BSWeeo

Sets Delay-by-Events for tnrl > events in the range 1 - 4194303,

indusive. If an out of range or noninteger number is received a numeric-argument error is generated.

If the Word Recognizer Option is not installed and if EVEnt:WREcognizer or STArkWREcognizer is received, an option-not-installed SRQ error is sent.

Selecting STArkWREcogniter WREcognizer sets SWEep to 9sweep.

BSWeep STArt to ATRigger. 3uery returns DBE SWE:string,

STA:string, EVE:string, 30UN: <nrl>;, or DBE

wg:string; if an argument is given n the query.

Description

626 24X5A/2467 Instrument Interfacing Guide

Table 6-7 (cant)

W/B Commands

Header

Argument

LTRigger ASWeep:

LTRigger?

RESolution

AUTO

RlNs RlOOps RIOPS

RESolution?

Argument

AANdb AORb WREcognizer

WREcognizer

Description

Configures the Logic Trigger function. If the Word Recognizer Option is not installed and if either the ASW:WRE or BSW:WRE command is received, then an option-not-installed error is generated.

Query returns LTR ASW:string; or LTR BSW:WRE;.

Sets the resolution of delay and delta-delay measurements.

Quetv returns RES strina:

24X5AI2467 Instrument Interfacing Guide 6-27

GPIS Commands

Table 6-8

Word Recognizer GPIB Commands

Header

WREcognizel

Argument

CLOck:

RADix:

WORd:

Argument

ASYnch

DNClock

UPClock

BlNary HEX

OCTal

<ASCII binary

data>

Description

Configures the Word Recognizer.

The RADix: argument controls only the format of the Word Recognizer display and manual

settings.

The format of ASCII binary data is

#Y followed by 17 digits, where each digit may be either 0, 1, or X (don’t care). Spaces may bs used anywhere to separate groups of digits. The option will accept ASCII binary data command arguments without the #Y prefix. The following are all valid and equivalent:

WOR:#Yl 00X01X10

0x0x110x,

WOR:#Y100X01X100

x0x1 10x.

WOR: 100x0 1x10

oxox 110x.

WOA:#Yl 0 0x0 1x1

00x 0x1 10x

The digit order is qualifier bit, then a 16-bit word in most-significant to least-signifcant bit order. All 17 digits must be sent. If an error is detected in the ASCII binary data argument, a command-argument error is generated.

6-28

REV OCT 1986 24X5Af2467 tnstrument interfacing Guide

Table 6-6 (cant)

GPIB Comnrands

Header Argument Argument

WREcognizer?

CLOck RADix

WORd

GPIB Command Set for the DMM Option

1 OFbgument DMM Header

susp

Description

If the Word Recognizer Option is not installed and any word recognizer command or query is received, an option-not-installed error is generated.

Query returns WRE RAD:string, CLO:string,WOR: <ASCII binary data>;. For example, WRE? WOR returns WOR:#Yl 00x01x10 0x0x110x;

Table 6-9

Description

Turns off the DMM. Any DMM function command turns the DMM on. The DMM SUSP; command suspends DMM operation to permit another function to occupy the readout space. The only difference between DMM SUSP and DMM OFF is that the next

time a OMM function is selected, if it is the

same function previously suspended, the reference value and the states of SMOOTH,

AUTO, etc. are maintained.

DMM?

DMMSend DMMSend?

24X5A/2467 Instrument Interfacing Guide

Query returns DMM ON;, DMM SUSP;, or DMM OFF;.

Command/query returns the displayed DMM measurement in tnr3> format, adjusted to basic units of volts, ohms, or amperes. DMMSend and DMMSend? have identical

effects. No response will be given unless or

until a measured value is displayed. If the

value is out of measurement range, the value

1 .OE +99 is returned.

6-29

GPlB Option Commands

Table 6-9 (cant)

Header

DlSplay

DISplay?

MlNMaxres

RANge inrx>

RANge?

REFset

Argument

MINtmum MAXimum

REF NORmal

I

<nrx>

1

Description

Select the minimum or maximum

measurements made since the function was

selected or since MinlMax Reset. Selects the present value of the reference. Selects the most recent measurement.

To receive the present minimum value over

the GPIB, for example, send DIS MINI;

followed by DMMSEND;. Query returns DIS MINI;, DIS MAX;, DIS

NOR; or DIS REF;.

Resets the minimum and maximum accumulators to the next valid measurement value.

Selects the range of the DMM function suited to measuring the value <nrx>.

Query returns RANGE <nr3>;. The range value will ba stated in basic units of volts, amperes, or ohms.

Sets the reference to tnrx>. If the argument is zero, the reference turns off. Also, if the argument is a negative value and the present function doesn’t allow negative values, the reference turns off. The argument

is rounded up to the closest value

represented by the DMM (1 part in 40,000). If the argument is too large for the function,

an error is generated and the reference remains unchanged. If no argument follows

REFSET, the reference value is set to the

displayed value. The command is illegal with the Continuity function.

I

6-30

24X!%/2467 Instrument interfacing Guide

. “_

GPlB Commends

Header

REFset?

HOLd ON

OFF HOLd? SMOoth

SMOoth?

AVGs?

DCV ACV DCA ACA HlOhms LOOHms DBV DBM DEGC DEGF

CONt

ON

OFF

tnrx> tnrx> tnrx> <nrx> tnrxb tnrx> tnrx>

cnrx>

Argument

Table 9-9

(cant)

Description

Query returns REFSET tnr3>;. The reference value will be sent in basic units such as volts, ohms, or amps. The query is illegal in Continuity.

Freezes the display with the present measurement.

Query returns HOLD ON; or HOLD OFF;. Turns smoothing on or off. SMOOTH ON

resets the number of measurements averaged to zero.

Query returns SMOOTH ON; or SMOOTH

OFF;.

Query returns AVGS <nr3> ;. The value of

<nr2> reflects the number of measurements value presently displayed. If smoothing is off, the query generates an error.

Select DMM measurement functions, with the measurement range suited to measure the value of tnoo with the best available resolution. If the argument is omitted or zero, the DMM will autorange. If the argument is negative, the DMM will autorange after initializing the range according to <nrx>, except for the dBV and dBm functions. If tnrx> exceeds the highest range, an error is generated and the command has no other effect.

averaged

in the smoothed

24X5A12467 Instrument Interfacing Guide 6-31

GPls Option Commands

Table 6-9 (cant)

Header

FUNCtion?

OVEr

OVEr? TONE

TONE?

HIZ

ON OFF

<nrx>

ON

Argument

Description

Query returns “function name” tnr3>;. The value of tnr3> is the highest value in the present range. The <nr3> value is omitted for fixed-range functions, eg.

DEGC. If the DMM is autoranging, the

range value is preceded by a minus sign, eg. DCV -2.E+ 1, except for the dBV and dBm functions.

Turns the over range warning SRQ on or

Off.

Querv returns OVER ON; or OVER OFF;.

Selects the tone to be used by the

Continuity function according to tnrx> in the 1 to 4 range. The default value is 1.

Query returns TONE <nr3>;. The value

of tnr3> is the selected tone

Selects the input impedance of the DCV

function in the 206 mV and 2 V ranges. No

argument or the ON argument selects an

input impedance > 100 GQ. while OFF

selects 10 MQ input resistance. During calibration ‘Settable Input Impedance”

must have been selected or a Settings

Conflict error will be generated.

value.

HIZ?

BEEp

<t<:d>><,t:d>...

Guery returns HI2 ON; or HIZ OFF;.

Generates a series of tones <t> of durations td>, where multiple tones are

specified by separating groups of

arguments by commas. The DMM must be either off or suspended or a mode error (254) is generated. The range of values for tisOto13andfordisl to255.If

arguments are not specified, default values of 6 for t and 3 for d are used. A value of 0 for t produces no sound, and each unit of d is approximately a duration of 0.1 second.

24X5A/2467 Instrument Interfacing Guide

Table 6-10

Calibration and Diagnostic Commands

GPIB Commrrnds

Header

CALibrate

GO

LOOping

Argument

<nrl > :

ON OFF

Argument

<ml>

Description

NOTE:

Calibration and commands should be used only for programmed maintenance procedures. They have no application for measurements.

Initiates Diagnostic mode and the Calibration routine indicated by the arguments, if the internal CAUNO CAL jumper is in the CAL position. The first digit of the first argument represents an option. The second digit of the first argument represents the specific routine.

The second argument is a step number within the routine. Refer to the Service Manual for information about the calibration routines. The

option numbers are the same as described for the ID? ctuery.

Executes the currently selected

CALIBRATION or TEST routine. This command has the same effect as pressing the upper Trigger COUPLING button when in

Diagnostic mode. Enables or disables looping of

diagnostic tests in diagnostic mode.

diagnostic

LOOping?

NORmal

24X5AI2467 Instrument Interfacing Guide 6-33

Query returns LOO ‘string” ;. ‘String” is either ON or OFF.

Exits Diagnostic mode. The command has no effect in normal mode. Commands following NORmal in the same message give unpredictable results. NORmal should be the final or only

command in a message.

GPlB Commands

Table 8-10 (conl)

Header

STEp

STEP?

STOp

TESt

TESt?

Argument

tnrx>:

Argument Description

Increments the currently executing Diagnostic routine to its next step.

Query returns STEP current step number is given by

<nrl>.

TERMINATES the currently

executing Diagnostic routine.

Control returns to the Diagnostic monitor.

tnrx>

Selects Diagnostic mode test sequences. The first argument

represents an option, and the

second is the routine number. See CALibrate command for option numbers.

<nrx >

Executes the selected test and returns the test’s status value:

TES < nrl >. Zero Is returned for

a passed test.

tnrl >;. The

6-34 24X5N2467 Instrument

Interfacing

Guide

Measurement Techniques

Introduction

This section gives some important considerations, measurement procedures,

and brief program examples for semiautomatic and automatic measurements. Examples in the Programming Examples section are shown in BASIC dialects for the Tektronix 4041, IBM PC/XT/AT, and HP98XX. Many measurements. such as frequency, period, and time interval and any operator-interactive measurements, require only the capabilities available with the highly efficient test-program generators d8SCrib8d earlier.

Trigger Settings

Select DC coupling for vertical inputs and triggers, unless unusual signal

characteristics require blocking dc, low-frequency, or high-frequency components.

NOISE REJ trigger coupling preserves full frequency response but increases the slgnal amplitude requirement. Trigger level is calibrated and predictable only with DC or NOISE REJ trigger coupling and DC vertical input coupling. Also, to have calibrated trigger level, the V/DIV VAR of the trigger source must be at the

calibrated position and the source must be a single channel.

Set trigger level at the midpoint between the positive and negative peaks of the signal, for most mea.surem8nts. With repetitive signals, set trigger level at the signal midpoint by pressing the INIT@50% button or sending the ATRfGGER

INIT or BTRIGGER INIT command.

a

Use NORM trigger mode for most automatic measurements. With AUTO LVL mode, the instrument attempts to trigger on static signals, which could result in anomalous measurements. AUTO LVL also takes time to acquire the trigger level, which is an unnecessary delay when the correct trigger level is known.

Frequency and period measurements are immune to trigger level errors, so long as trigger level is near the signal midpoint and the signal amplitude is

24X5Ai2467 Instrument Interfacing Guide 7-l

adequate.

Me88W8l?l8nt TeChfIiqU8S

When measuring time with the B Sweep and B Trigger, trigger-level uncertainty can interact with signal transition times to cause measurement errors. Consult the trigger level specifications and consider the signal slew rate to determine how

much error to expect. The effective trigger level may change slightly with different waveforms or with different instruments using the same trigger level data. However, trigger-level for a given instrument, making a given measurement, is

accurately repeatable.

Minimize trigger-timing errors by programming trigger levels to exactly fit a measurement, Use the B Sweep to expand the display and observe superposition of the transitions defining a measurement. Set the B-Trigger level to superimpose the points of interest and save the setup for future use.

Automatic deltadnlay-time measurements between two channels require a single channel source for the A Trigger, VERT source for B Trigger, and ALT

vertical mode. B-Trigger levels for the pair of delays should be set independently,

using the TRIG A DLY and TRIG AFT DLY modes or using the following commands:

BTRIGGER LEVEL: tnrx>;

for the delta-delay reference trigger, and

BTRIGGER DLEVel: <nrx>;

for the deltadelay trigger.

If the transition time of the signal is a big part of the allowable error, program the instrument for an automatic measurement, then pause for operator intervention. An operator should carefully set B-Trigger LEVEL as required for exact superposition of the points of interest. If you use RUN AFT DLY B-Trigger Mode,

the operator should adjust the A REF and A controls for superposition.

Superposition avoids the effects of waveform changes and trigger level uncertainty.

Measuring lime Intervals on Repetitive Signals

First, manually set the instrument to measure delta-time, following this outline:

1. Select the desired measurement resolution, using the MENU. AUTO gives the fastest response.

2. Trigger the A Sweep, using NORM mode, on a signal that occurs at least 70 ns before the interval of interest.

7-2

24X5AJ2467 Instrument Interfacing Guide

3. Set the A-Sweep SEC/DIV to display the interval of interest.

4. Use the B Sweep to expand the waveform and superimpose the points on the waveform(s) that define the beginning and end of the interval. The delay controls, A REFerence and A, determine two times at which the B Trigger

is enabled. The B Triggers, with independent slopes and levels set in TRIG

AFT DLY and TRIG A DLY modes, determine the exact point of

intersection of the superimposed B-Sweep displays.

5. In some cases, signal variations could cause the wrong transition to ba recognized as the beginning or the end of an interval. Set A REF and A so that the B Trigger is enabled for the events of interest over any expected variation of the signal(s) under test. One way is to set each of the controls in the moddle of the range over which it triggers on the desired transition.

6. Store these control settings by using the ‘learn” procedure given in the ‘Programming Examples” section.

7. To automatically measure delta-time with similar signals, send the recorded

settings back to the instrument and read the result. See the Programming Examples section for the GETClTN subroutine.

100 Print#ecopetaetS 110 Call CLTCTTg(delta)

! Send previoua1y stored settings

IBM

Tek

340 CALL IBWRT(SCOPE%,SET$)'Send pr.9ViOUS setting 550 GOSIJB (Statement lOumber of Get CTT routine)

HP

450 OUTPUT D2465;SetS !Send 440 CALL Get-cttn(D2485,Intervel)

previously

stored

setting

If you require the best possible delta-delay-time accuracy, and if signal transition time is a big part of the allowable measurement error, program the instrument for an automatic measurement, except for a pause for an operator to

carefully set B-Trigger LEVEL for exact superpositiin of the points of interest. This

is the only way to completely avoid the effects of waveform changes and trigger level uncertainty.

24X5A12467 Instrument Interfacing Guide

73

Measurement Techniques

Measuring Single-Shot Time Intervals

To make single-shot measurements, you must use the delay-time mode with AUTO RESoWion. Establish the conditions for automatic measurements by manually operating the instrument. The following steps will generate a program to measure delay time automatically.

1. Select AUTO measurement resolution, through the menu.

2. Set the A Trigger to respond to the signal transition that defines the beginning of the interval of interest, using NORM mode.

3. Set SEC/DtV to display the interval of interest on the A Sweep, with delta-

time off. Be sure the interval is at least 70 ns.

4. Pull the SECKIIV knob out to display an intensified zone. Set the DLY POS

control and the B-Trigger controls, with TRIG APT DLY mode, for the end of the interval. DLY POS determines when the B Trigger is enabled. Delay should be set at zero for most measurements, such as pulse widths and propagation delays.

5. If more than one transition could be recognized as the end of the interval,

set DLY POS so that the B Trigger will be enabled for the event of interest, over any expected variation of the signal(s) under test. One way is to set DLY POS in the middle of the range over which the B Trigger recognizes the desired transition.

6. Transfer the instrument settings to the system controller.

A program to automatically measure delay-time with similar signals should send the recorded settings back to the instrument and call the GETCTTN subroutine, listed in the Programming Examples section.

Tek

100 Print#scopelaett 110 Call CETCTTN(interva1)

!Send previously etored eett1ngs

IBM

540 CALL IBWRT(SCOPE%,SET$)'Send 350 GOSUB (Statement

Number or Get CTT routine)

preVlOllS setting

HP

430 OUTPUT 440 CALL Get-cttn(D2465,Interval)

7-4

DZ465;Setl ISend previously stored Betting

24X5A/2467 Instrument Interfacing Guide

Measurement Techntques

Measuring Peak Voltages

Trigger coupling should be set at DC and verttcai input coupling should be set at DC. Always display the signal with at least three divisions of amplitude. Larger amplitudes, up to twenty divisions, provided each peak of the signal Is within ten

divisions of ground, generally give more repeatable peak voltage measurements.

Set the A Sweep at any convenient speed faster than 10 msldivislon, for any slgnai period less than 20 ms. For signal periods up to 200 ms, set SEClDiV slower than

0.25 times the period. SEC/DIV settings from 50 ms to 500 ms allow measuring the peaks of signals having periods up to 200 ms.

Manually set the instrument for the measurement and store the settings in the

controller with an ‘iiset?” query. An automatic test routine should return the

settings to the scope and then call the GETPEAKS subroutine, listed in the Programming Examples section.

Tek

100 Prlnt#seopelaetS I Send PreViOUBly stored settings

Call

110

GETPEAKS(hlSh.

120 pktopk=hiSh-low

1OlI)

IBM

220

CALL IEWRT (SCOPEX.SETS)'Send prOViOU0 setting

230

GOSIJB (Statement Wumber of Get Peaks routine)

PKTOPK- HIPEAK-LOPEAK

240

HP

120

OUTPUT D2465:SetS ISsad previously

130

CALL Get-peaks (D2485.Hipsak.Lopeak)

140

Pktopk = Hlpsak-Lopsak

stored setting

24X5A12467 instrument interfacing Guide 7-5

Measurement Techniques

Measuring Rise and Fall Times

A system comprising a controller and an oscilloscope with CTT and GPIB can

measure transition times automatically, on repetitive signals. The system measures

peak voltages and calculates the appropriate trigger levels for delay

measurements, The trigger levels define points on a signal transition from which

delay times are measured. Transition time is the difference between delay times with the trigger level set at 10% and 90% of the transition amplitude.

Waveform variations and trigger system distorttins make transition time measurements less accurate than other time measurements. Even so. these measurements are adequate to characterlze or verify many devices and systems, especially if the measurements are optimized by the techniques described here.

The best procedure for measuring rise trme or fall time depends on signal characteristics. The oscilloscope requires 70 ns after the A Trigger before enabling

the B Trigger, with delay set at minimum using either the DLY POS controt or a DELAY -0.05 command.

l

If a pulse is wider than 70 ns. the A Trigger and the 8 Trigger can operate on

opposite slopes of the pulse.

l

If the pulse is shorter than 70 ns, the 6 Trigger should be set for the same slope as the A Trigger. The A-Sweep rate and delay should be set so that the B Trigger operates on a later cycle of the signal.

l

If the high and low states of the pulse are at least 10 microseconds long, the necessary signal delay to the B Trigger can be supplied by using HF AEJ coupling. On such low-frequency signals, Using HF REJ and same-slope triggering gives faster results and better resolution than opposite-slope triggering with DC coupling.

Depending on signal characteristics, use one of the following procedures to manually set the instrument for a delay measurement. Always display the signal with at least three divisions of amplitude. Larger amplitudes, provided each peak of the signal is within ten divisions of ground, generally give more repeatable measurements. These measurements are made by the trigger and time-interval counter systems and are independent of the display.

l

For pulses more than 70 ns wide:

1. Set A Sweep to display the rising and falling edges of the signal, wrth the A Trigger set for the transition of interest, and delta-time off.

7-6 24X5A/2467 Instrument Interfacing Guide

Measurement Techniques

2. Pull the SEClDlV knob out to display an intensified zone and set DLY POS for zero delay.

3. Select TRIG AFT DLY mode for the B Trigger. Set B-Trigger SLOPE opposite from the A Trigger. Set B-Trigger SOURCE and LEVEL to trigger the intensified zone at the pulse transition after the transition of interest.

. For pulses shorter than 70 ns:

1. Set A Sweep to display one cycle of the signal, with A Trigger set for the transition of interest, and delta-time off. SEC/DIV should be set at 10 nsldiv for any signal with a period less than 100 ns.

2. Pull the SEC/DIV knob out to display an intensified zone and set DLY POS at minimum.

3. Select TRIG AFT DLY mode and DC coupling for the B Trigger. Set B-

Trigger SLOPE the same as the A Trigger. Set B-Trigger SOURCE and

LEVEL to trigger the intensified zone at a later pulse transition than the

transition of interest.

4. While holding the A/B/MENU button depressed to access the A-Trigger controls, vary LEVEL. Verify that the B Trigger responds to the same signal cycle with any A-Trigger LEVEL setting that could be used. If the intensified zone jumps from one cycle to another, reset DLY POS to

enable B Trigger at a time such that the intensified zone tracks the

same transition for all usable settings of A-Trigger LEVEL. Set DLY POS in the middle of the range that produces proper operation.

9 For pulses with both high and low states at least 10 microseconds long:

Set the oscilloscope controls to display the signal. Set the A Sweep at 1 microsecond/division. Set the A Trigger for the transition of interest. Set delta-time off.

Pull the SEC/DIV knob out to display an intensified zone and set DLY POS for zero delay.

Set the B Trigger to TRIG AFT DLY Mode, the same SLOPE and SOURCE as the A Trigger, and HF REJ Coupling. Then press INIT@

to set the B-Trigger Level.

24X5Al2467 Instrument Interfacing Guide 7-7

Measurement Techniques

l

For pulses of any width and period, with an auxiliary pulse occurring at least

70 ns after the transition of interest:

1. Display the transition of interest on one vertical channel and the auxiliary pulse on another channel. Set A-Trigger SOURCE and SLOPE for the transition of interest. Set delta-time off.

2. Pull the SECJDIV knob out to display an intensified zone and set DLY POS for zero delay.

3. Select TRIG AFT DLY mode and DC coupling for the B Trigger. Set BTrigger SOURCE and LEVEL for the auxiliary pulse. If necessary,

readjust DLY POS to position the intensified zone at the earliest

possible transltion of the auxiliary pulse and such that the intensified zone remains on the same transltion for all settings of A-Trigger Level

(while holding A/B/MENU for access to the A Trigger).

Transfer the appropriate instrument settings to the system controller.

To automatically measure transition time:

1. Return the appropriate, recorded instrument settings and measure

positive and negative peaks of the signal, using a procedure such as the followmg. See the Programming Examples section for the GETClTN and GETPEAKS subroutines.

Tek

100 Print#scope:set$ ! Send previously stored settings 110 call CETPEAKS(hipeak. lopeak )

120 pktopk=hipeak-lopeak

IBM

220 CALL IBWRT (SCOPE %. SETS ) 1 send

previous setting 250 COSUB (Statement Number of Get Peaks routine) 240 PKTOPK= HIPEAK-LOPEAK

HP

120 OUTPUT D2465;SetS ! Send previously stored setting 130 CALL Get-peaks (D2465,Hipeak.Lopeak) 140 Pktopk = Hipeak-Lopeak

24X5Al2467 Instrument Interfacing Guide

Measurement Techniques

2. Set the B-Trigger level to the average of the positive and negative peak values, using the BTRIGGER INIT command.

Set the A-Trigger level to the negative peak value plus 10 percent of the

3. difference between the positive and negative peaks.

Tek

250

10r=O.l !Typically lO%,

260 Print#scope:'btr

level:"; lopeak+lor'pktopk

!Send 1OW level to the A Trigger

may

be changed

IBM

1100 1110 1120

L0a=0.1 ATRLEV$="ATR CALL IBWRT (SCOPE%, ATRLEVS)

LEVr "+STR$ (LOPEAR+LOW*PKTOPK)

HP

1100 1110

270

Low=0.1 OUTPUT 02465: "atr

4

Read the delay time.

Call getcttn(delayl)!Get

levr

“k

VALS (Lopeak + Lo.*Pktopk)

first measurement

5. Set the A-Trigger level to the negative peak

value

plus 90 percent of the

difference between the positive and negative peaks.

280 high=O.B !Typically

Print#scope:“atr level: -:lopeak+high'pktopk

290

Read the delay time.

6.

300 Call

getcttn

(deleyZ)!Get

!Send 90% level to

90%.

may be

second measurement

7. Subtract the second reading from the first to obtain rise time.

changed)

A-trigger

310 Risetime=delayl-delayZ!Delay difference

If the A-Trigger SLOPE is negative. the result will be negative and the

measurement WIII be the negative of fall time.

24X5A12467 Instrument Interfacing Guide

7-9

Mt?ffsuremt?nt T8chniques

Trigger Level Compensation

Because of signal distortions in the trigger system, a transition time measured with calculated 10% and 90% thresholds of the waveform, especially with fast transitions. Any discrepancy can be treated as an error in the measured peak voltages, which correspond approximately to the 0% and 100% values of the transition region. Even with this discrepancy, transition times of similar signals with similar repetition rates can be compared to a reference with enough accuracy for most applications. For good accuracy, use the CTT and trigger system to measure transition times comparatively, and use the cursors to

determine actual values.

1. Carefully measure a transition time using the delta-time cursors.

2. Measure the same transition time by the appropriate procedure. above.

3. Estimate new values for the ‘low’ and “high” variables (initially 10% and 90%) as required to adjust the CT and trigger measurement to agree with the cursor measurement. Adjust “high” if the transition is much slower at the high end than at the low end, such as an exponential step. Adjust ‘low” if the transition is much slower at the low end. If one peak has a large overshoot, adjust the variable near that peak. If both peaks are severely overshot, both “high’ and “low” should be adjusted. If the transition slew rate is constant and pulse distortions are less than 5%, adjust onty ‘high”

for rise time or “low” for fall time. Repeat the measurement, estimation of

new values, and the trigger-level adjustment steps until the desired accuracy is achieved.

may

not agree with a direct measurement

Programming Examples

Each of the examples assumes the following declaration statement or an equivalent. For illustration, the GPIB address of the oscilloscope is assumed to be 1.

7-10 24X5A12467 Instrument Interfacing Guide

Measurement Techniques

Tek

10 scope=1 ! Assuming GPIB adrs is 1

IBM

ior

for

Scope

10 SCOPE$="o2465" !String name Of scope

20 CALL IBFIND(SCOPE$.SCOPE%) !Returns with

30 IF IBSTA%<O

THEN (Statement Number of ERROR ROUTINE)

! GPIB driver must = name given ! in IBCONF.

! SCOPE% I/O address ! seen through CPIB driver. ! I/O statements use SCOPE%

HP

10 D2465 = 701 !I/0 pointer

!address

= 700

plus Scope

The system controller can “learn” the oscilloscope settings for a given test, using a

routine similar to the following.

Tek

20 Dim set$ to 180 !Array to store settings

. * . . . .

110 Print#scopa:"llsetY"!Ask for settings

120 1nputffscope:set.T !Put setup into set$

IBM

query

Ior settings

binary setting

string once.

into SETS

20 SETS=SPACES (160) 30 SETQUER$='~lsetY

. . .

. . . 110 CALL 120 CALL IBRD(SCOPE%,SETS)'Put

IBWRT (SCOPE%,SETQUERS)*AS~

'String to store

'Define

set

setup

HP

20

Dim

. , .

SetSll801

. . . 110 OUTPUT D2465;‘11set?"!Ask for settings 110 ENTER D2465;Setf !Store in Sets

!Array to store settings

24X5A12467 Instrument Interfacing Guide

7-11

The ‘Ilset?” query transfers binary control data to save time. If your controller will not support eight-bit binary data transfers, you can use an ASCII transfer. To store instrument settings as ASCII data, dimension the set$ array, above, to 1200 bytes and replace ‘llset?” with ‘set?“.

The instruments, interacting with an operator, can measure time with cursors, delay time, or delta-delay time. With the CTT, they also can measure delay time or delta-delay time without an operator, using TRIG AFT DLY and TRIG A DLY STrigger modes.

7.12 24X5Al2467 Instrument Interfacing Guide

Table 7-l

Delay Time and Della-Delay Time

Measurement

Techniques

Mode Query

Cursor At or l/At

Delta-Delay Al

or

l/At

Delay

Delta-Delay At l/At

or Delay, with

Cl-l

or

TDELTA?

DELAY?

CTSEND?

Conditions and Results

Requires [l] A-Sweep or B-Sweep display

(not ALT or INTEN) [2] cursors on with

1lAt [3] operator to set DLY POS control. Gives time or frequency in seconds, hertz, percent, or degrees. If cursors are active,

DELTA? MODE query returns DELTA MODE:CTIME or DELTA MODE:CPERTIME. In the special case where cursors are active with B-Sweep delayed by events (with ClT) the last three

characters of a MESSAGE? query are BSW.

Requires [l] INTEN. ALT, or B-Sweep display [2] RUN AFT DLY B-Trigger mode [3] operator to set A REF and A controls. Gives time or frequency in seconds, hertz, percent, or degrees. (Invalid result is returned with TRIG AFT DLY.) If is active without cursors, a DELTA? MODE:

query returns DELTA MODE:TIME OT

DELTA MODE:PERTIME. Requires [1] INTEN, ALT, or B-Sweep

display [2] RUN AFT DLY B-Trigger mode

[3] operator lo set DLY POS control. Gives

delay setting in divisions which must be

multiplied by A-SEC/DIV to determine delay

time. (Invalid result is returned with TRIG AFT DLY.)

Requires [l] INTEN, ALT, or B-Sweep

display [2] TRIG AFT DLY or TRIG A display [2] TRIG AFT DLY or TRIG display (21 TRIG AFT DLY or TRIG A or

Delay, DLY B-Trigger mode [3] appropriate

with ClT settings to frame desired measurement 14) selecting

INTEN or ALT mode or with DELTA

MODE:TIME or DELTA MODE:PERTIME command. Alternative to requirement [2] is

RUN AFT DLY B-Trigger mode and operator to set A REF and A controls. Gives time or frequency in seconds or hertz.

At

or l/At

At

or l/At in

At

At or

or l/At

24X5A/2467 Instrument Interfacing Guide

REV OCT 1986

7-13

Programming Examples

Tektronix 4047 Program to Send Commends to the

Oscilloscope

The program first asks for the GPIB address of the oscilloscope, then asks for a command to be entered at the keyboard. Any response from the oscilloscope is displayed on the controller. A serial poll is performed in response to service request (SRQ). The service request and the EVENT codes are then displayed.

100 ! Program to send commands and queries ++++ and receive responses 110 ! from TEKTRONIX 2400-Series

++++ Oscilloscopes

120 ! 150 Init all 140 ! Disable SRQ handler until ready 150 Disable 160

! Get address

170 Print ‘Enter the CPIB address of the

++++ oscilloscope:

180 Input addr$ 190 ! Set up physical and logical unit 200

! Set

++++ communication. 210 ! 220 Set driver “gpib0 (eom=<O>)r” 230 Open #lz’gpibO (pri=“&addr$C”, ++++ eom=<O>)r” 240 ! 250 ! Enable SRQ handler 260 On srq 270 Enable 280 ! 290 Repeat: ! Sending command 500 Print n * 310 Print 320 Print “Enter command or query: 330 ! Get the command 340 Input a$

srq

up so only

then

gosub

srq

l

* * *#

of the oscilloscope

“;

EOI can terminate

srqhdl

or query

“;

the

24X5A/2467 Instrument Interfacing Guide

A-l

Appendix A

! Send command or query

350 360

Print #lra$

370

! Get response

380

DIM resp$

390 Input

to

#1 rresp$

if there is any

2000

to scope

400 Print 410 ! If no response ++++ another

420

If len (resp$)=O

430

! If yes

then print the

440 Print ‘Response

then prompt for

command

then got0

repeat

response

from the oscilloscope +-i-t+ iSI ” 450 Print

460

Goto

reap8

repeat 470 Srqhdlr ! routine to handle the 480 Poll stb,dev 490 Print #devr’event?”

500

! Get event Input #devrevent

510

number

520 Print “Instrument #‘;dev;*status

++++ byte=n;stb;w

,event=w;event

530 Resume

Tektronix 4047 Program to Calibrate Trigger Levels for Transition Time

!A Tektronix

10

-l-t++

20 ! for 30 ! 30

40 !

50

!Noter

to Adjust Trigger Thresholds Transition

w++++* in place of line number

++++ indicates printed break

! in

60

t+++

70 ! 80

long

without - ++++. or break.

Compress ! 4041 housekeeping 90 Scope=1 !Use actual GPIB adrs of ++++

100

True=1

Oscilloscope

110 False=0

120

Integer

count

4041

BASIC Program

Time Measurements

June 1986

line, which must be entered

sw

A-2

. “.*._ _.‘.,,,, x ..-, -.

ZiX5A12467 Instrument Interfacing Guide

Appendix A

130 140 150 160

++++

170

++++

Count=0 Risetime=O Print Print “Execute this procedure and

program to find the

Print “high and low thresholds for

transition time measurements.” 180 Print 190 Print “Repeat

the procedure to find

++-I-+ the opt imum thresholds

200

210 220 ++++ 230 240 +t++ 250 ++++ 260 270 +++t 280 ++++ 290 tttt

300

t-l-++

310 320

++t+

330

++++ 340

350

++++

360

370 ++t+ 360 +t++

390

Print “each dissimilar Print Print “1. Connect

oscilloscope to

controller IEEE-488 bus.”

Print Print “2. Carefully

transition time

Print ” Use

10% and 90% or 20%

measure

with cursors.”

and 80% as appropriate.” Print Print “3. Manually set the scope to

measure the transition of” Print ”

control settings

Print ” used

interest, with the same

that will be”

in the automatic test.

Review ““Measuring Rise” Print ” and Fall

Times”” to

determine the best settings.” Print Print “4. Enter transition time,

measured in step

2,”

Print ” in exponent ial

5.43e-9.” Print Print ” Use minus time for fall

time, eg. -32.7e-6.”

Print

Input prompt “Transition

“#actual

Wbyte dcl ! Send Device

to GPIB

Highok=true

opt imum”

for”

signal. ”

form. eg.

Time :

CLear message

24X5A12467 Instrument Interfacing Guide

A-3

Appendix A

400 Lowok=true

410 ++++ adjusted 420

Low=O.l !Typically 10%. may be

later.

High=0.9 !Typically 90%. may be ++++ adjusted later. 430 Print 440 Print "Enter

""y<RET!JRN>"'

for

ii++ ""yes,"" or '.n<RETURN>""

ii++

for

"lnO*"".

450 Print 460 Input prompt 'Are ++++ threshold other than

using a low

YOU

10%Pgransner$ 470 If answer$<>"y' then got0 ask90 480 Input prompt "Enter

low threshold ++++ value as decimal fraction: "IlOW 490 500 If lOW>0.9 then 510 AskSO: input prompt 'Are

If 10w<0.02 then 1ow=O.l

low=O.l

YOU

++++ using a high threshold other than ii++ 90%?'ranswer$ 520 If answer$<>'y"

then got0 askx 530 Input prompt "Enter high threshold ++++ value as decimal

540 If high<O.l then 550

If highs0.98 then high=0.9

high=0.9

fraction8 "thigh

560 Askxr print -Initial low ++++ threshold=';lor;" Initial high ++++ threshold=.;high 570 Print "Is the transition OBVIOUSLY ++++ slower near the high than ++++ near the low? 580

Input ansrerS

590 If answer$="y" then

If

600

answer$="y" then got0 aberr

610 Print "IS the transition

";

highok=false

OBVIOUSLY

++++ slower near the low than

++++ near the high?

l :

620 Input ansrer$

630 If answer$="y. then lonok=false 640 Aberrr !

650 Print "Do both high and

low

levels

++++ have less than 5%'

4-4

24X5/\/2467 Instrument Interfacing Guide

Appendix A

660

++++ 670 680 690 ++++ 700

++++ 710 720

730 740 750 it++ 760 ++++ 770 780 790

800 Measure: 810 Print ‘Wait ++t+

a20 ++++ 830 ++tt 840 850 860

Print .

tilt, or other

overshoot, undershoot,

aberration? Input anawer$ If answer$=.y. then got0 measure

Print “Does high level have less

than 5%’

Print ” overshoot. undershoot,

tilt, or other

aberration? Input answer$ If answer$<>“y” then highok=false If answer$=.yr* then lorok=false

If answer$=“y* then got0 measure

Print *Does low level have less

than 5%”

Print W overshoot, undershoot,

tilt or

other aberration?

Input answer$ If answer$<>“y” then lowok=false

!

!Measurement Routine

iterative

for

q easurements.n

Highx=false !Don't change high

unless required

Lowx=false !Don't change low unless

required If highok=false then highx=true If lowok=false then lowx=true If highok=true and

lonok=true and

++t+ actual*0 then highx=true

870

++++ 880 890

t+++

900

910

If highok=true and lowok=true and

actual<0 then lonx=true Call Pktopk=hipeak-lopeak

getpeaks (hipeak,lopeak)

! Find

peak-to-peak

! Send

Print

50% level

#scoper’btr

to B-trigger

levelt”;lopeak+ t+++ (0.5 ‘pktopk) 920 930

Hlprev=O.8

SlopeO=4 ! Initial ratio of +tt+ risetime/threshold 940 Accmcnt=O

l ;

“;

“:

24X5A/2467 Instrument Interfacing Guide

A-5

Appendix

A

950

Riseaccm=O

960 Hlaccm=O

970 ! 980 Againr ! Iteration Loop 990

1000 +ttt

1010

1020 H-t+

1030 ++++

1040

1050 +++t

1060

1070 t++t

1080 ++tt ttit

1090 +t++ 1100

++++

++++ 1110 ++++

++++

1120

++t+

1130 1140

++++

1150

+tt+

1160

tttt

1170 1180 1190

1200

Count=count+l

Print

#scoper”atr

level:“;

lopeaktlow l pktopk

! Send low level

Call

getcttn (delayl)

to A-trigger

delay reading

Print #scoperaatr level : “;lopeak

+high ‘pktopk

! Send

high level

to A-trigger

Call getcttn (delay2) ! Get 2nd

delay reading Riseprev=risetime Risetime=delayl-delay2 ! Delay

difference

If risetime/actual>0.99 and

risetime/actualcl.Ol

got0 finish

If count>19 then got0 finish

!Can’t converge within 1%

If count>1

+abs ((risetime-

then

riseaccm=riseaccm

riseprev )

/risetime)

If c0unt>1 then hlaccm=hlaccm

+abs ( (high- low-hlprev)

I (high-low ) )

If hlaccm>0.02 then slopeO=

riseaccm/hlaccm Slope=slopeO If highx=true

lowx=true then

and

slope=slope ‘2

Change= (high-low) * (actual/risetime

-1) /slope

If hlprev>0.95 and high=0.96 and

10w=0.02

then got0 finish

Hlprev=high-low

If highx=true then high=high+change If lowx=true then low=low-change If highzO.96 then high=0.98

! Get 1st

then

A-6

24X5N2467 Instrument Interfacing Guide

Appendix A

1210 If 10w<0.02 then low=0.02 1220 If (low+O.l)>high then got0 finish

++++ !Invalid "actual"

1230 If high=0.98 then 1owx=true 1240 If low=0.02 then highx=true 1250 Goto again 1260

! 1270 Finish: ! 1280

Print 1290 Print count;" iterations" 1300

Print "Use

these

new values for high ++++ and low with similar signals." 1310 Print " New value for high =

++++ ";high

1520

Print " New

value for

low =

++++ ";1ow

1330 Print "Measured Rise Time (Fall Time

++++ if 1340 If count>19 then

Negative)

= ";risetime

print

"Verify ++++ risetime measurement value.' 1350 1360 Print

Print

"Entered (target) Transition ++++ Time = ";actual 1370 Print 1380 ++++

If (high-low)<0.2

. t..

ENTERED TRANSITION TIME

then print

++++ OUT OF RANGE. ***I

1390 If high=0.98 and 10w=0.02 then print

++++ ++++

. ***

ENTERED

TRANSITION TIME OUT OF RANGE. I**"

1400 stop "-- Enter *"run"" to do another

++++

threshold optimization."

1410 End

1420

++++

Sub getpeaks (var

local timeref.resu1t.g

hipeak,lopeak)

1430 !Set A-trigger to INIT @ 50% for peak

++++

1440

Print

measurement cycle

#scope:"atr init50" 1450 timeref=ask ("time") !Starting time 1460 Waitpksc Input #scope prompt "atr? ii++ trigd"rresult$ !Triggered?

24X5A12467 Instrument Interfacing Guide

A-7

Appendix A

1470

++++

1480 +t+t +++t 1490

1500 ++t+ 1510 +ttt 1520 1530 1540 +t+t 1550 ++++ 1560 1570

it++

1580 1590 1600 1610

+++t

1620 1630

1640

1650 ++++ 1660 ++++ 1670 +t+t 1680 ++t+ 1690 tttt 1700 tttt 1710

If result$=‘ATR

found ! Peaks

If timeref+ZO*ask (‘time.)

waitpks

set

since start

TRIGDION;” then got0

found

then got0

! Loop

if < 20

!Else

Print n*** FAULTY PEAK VOLTAGE

MEASUREMENT

Print “Check oscilloscope

l l l

20

SECOND TIMEOUT”

settings

and signal source .w

stop

w-- Enter ‘Drun’a to try again.”

:

Found 8

Input #scope prompt “atr?

!

!Typical result string-- ATR MINI8

!Extract low peak from result string

Lopeak=val (results )

!Extract high peak from result string

Hipeak=valc (result$.pOS (results.

Return

End

Sub getcttn (var cttcount )

Long cttcount !To accept up to le99

Print #scoper’ctt reset” !Discard

Waiting8 input #scope

If cttcount=O then got0 waiting

Input #scope prompt “cts?“:cttcount

If cttcount<l.OE+S then return

! Else

! Ask instrument ror peaks by

A-trigger query

mini,

max.:resultS

-489E-3,MAXs496E-3;

“MAX’,l))

error code

stale measurements

prompt .ctr?”

lcttcount

! Hang

!Get

until ready

reading from scope

scope ready?

!Is

!>1ES count indicates error

A-8

24XiAl2467 Instrument Interfacing Guide

Appendix A

1720 Print 1*** FAULTY TIME OR COUNTING +ttt MEASUREMENT *** Error +t++ Code: ";cttcount 1730 t++t

Print 'Check of3cilloscope

signal

and

source:

settings

1740 stop '-- Enter narunn* to try again." 1750 End

IBM PC/X T/A T Program to Calibra tt

?

Trigger Levels for

Transition Time -

10 'XTNLEV.BAS-- a BASIC

tttt IBM PC/XT/AT

20 ' Tektronix GPIB User

+++t Utility (GURU

30 ' 40 ' National Instruments tttt

Instrumentation Interface 50 'To Adjust Trigger Thresholds for +tt+ Transition Time Measurements 60 ' with the Tektronix 24X5A and 2467 +t++ Oscilloscopes with CTT 70 ' 30 June 1986 80 'NOTE: .++++a in place of a line number tt+t

indicates that 90 ' separately printed ii++ joined. The *ii++" 100 ' symbols must not be entered. 110 'INITIALIZE 120 KEY OFF I SCREEN 0 I LOCATE

t+++ : CLS

130 'The following 6 lines load the

tt+t utilities

140

+t++

'are

necessary

This should be done

for program operation.

150 'at the beginning of every application it++ program. 160 CLEAR 10000,59665! 170 IBINITl = 59665!

program for the

with

8

Resource

)

01

IEEE-488

lines

into memory

must be

l.l,O

that

24X5Al2467 Instrument Interfacing Guide A-9

Appendix A

180

190 200

IBINIT2 = IBINITl + 3 BLOAD "bib.m" ,IBINITl CALL IBINIT~ (IBFIND,IBTRG,IBCLR,

++++ IBPCT,IBSIC.IBLOC,IBPPC,IBBNA, ++++ IBONL,IBRSC,IIBSRE.IBRSV,IBPAD, t+t+ BSAD,IBIST,IBDMA.IBEOS.IBTMOI ++++

210

IBEOT,IBRDF,IBWRTF)

CALL IBINITB(IBCTS,IBCAC,IB~~AIT,

++++ IBPOKE,IBWRT,IBWRTA,IBCllD,

tt+t IBCMDA,IBRD,IBRDA,IBSTOP.IBRPP,

t+++ IBRSP,IBDIAG,IBXTRC,IBRDI,

tttt IBWRTI.IBRDIA.IBWRTIA.IBSTA%, ++++ IBERR%,IBCNT%) 220 ' 230 'Use this program

only

ior

system ttt+ setup and calibration. 240 ' 250 SCOPE$="o2465"

'The

same name must +tt+ be assigned with IBCONF 260 ' 270 TRUE = 1 : FALSE = 0 tttt 'Initialize logical values 280 PRINT 290 PRINT*Execute this procedure and tt+t program to find the optimumg 300 PRINT 'high and low thresholds

for

++++ transition time measurements." 310 PRINT 320 PRINT"Repeat the procedure to find the tt++ optimum thresholds' 330 PRINT-for

each

dissimilar

signal."

340 PRINT 350 PRINT"1. Connect oscilloscope

++++ IEEE-488 bus and 360 PRINT'

++t+ must

Primary

equal

the

configure

address

of the scope

to

system."

370 PRINT" address assigned to 02465 tttt with IBCONF."

380 PRINT 390 PRINT"2. Carefully measure transition

tt+t time

with

curs0rs.g

A-10 24X5A/2467 Instrument Interfacing Guide

Appendix A

400 PRINT'

Use

10% and 90% or 20% and ++++ 80% as appropriate." 410 PRINT 420 PRINT"3. Manually set the scope to ++++ measure

430 PRINT- interest, with

++++

control settings that will be"

the transition o?.

the

same

440 PRINT* used in the automatic test. ++++ Review '"Measuring Rise 450 PRINT" and Fall Times" to determine ++++

the best settings." 460 PRINT 470 PRINT"4Q. Enter transition time, ++++ 480 PRINT" ii++ 490 PRINT' Use minus time

measured in step

in exponential

5.43e-9..

eg.

2,.

fOlYll.

for

fall time, ++++ eg. -29.6e-6." 500 PRINT 510 CALL ISFIND (SCOPE$.SCOPE%)

++++ 'Find scope specifier 'scope%'

520 IF IBSTA% < 0 THEN 2360

++++ 'Incorrect symbolic 530 IDTEST$='id?"

540

CALL IBwRT (SCOPE%,IDTEST$) 'First call ++++ to test scope address 550 IF IBSTAZ ++++

< 0 THEN 2360

'Incorrect address

560 CALL IBLOC (SCOPE%)

++++

'User

sets up

scope 570 INPUT'Transition Time: ".ACTUAL 580 CALL IBCLR (SCOPE%) ++++

'Send Device Clear message ++++ to GPIB 590 PRINT 600 PRINT"The LOW threshold is typically

++++

10% (0.1 as a decimal)" 610 PRINT" If this is your low ++++ threshold, just press <Enter>620 PRINT'

Otherwise,

type

in a new

++++ low threshold as a"

name

24X5A/2467 Instrument Interfacing Guide A-l 1

Appendix A

630 INPUT" decimal fraction and ++++

press

<Enter>: ..LOW

640 IF LOW < .02 OR LOW > .98

++++ THEN LOW = .l

650 PRINT 660 PRINT"The

HIGH threshold is typically ++++ 90% (0.9 as a decimal)* 670 PRINT" If this

++++ threshold,

just press <Enter>'

680 PRINT" ++++

high threshold as a9

new

690 INPUT'

++++

IF HIGH < .l OR HIGH > .98 THEN

700

press <Enter>: .,HICH

and

is your high

Otherwise,

decimal iraction

type

++++ HIGH = .S 710 PRINT 720 PRINT'Initial low threshold = ';LOW; 730 PRINT'Initial high threshold = ";HIGH 740 PRINT 750 PRINT"Enter

'Y' for a yea answer, or ++++ 'N' for a no answer.' 760 HIGHX = FALSE ++++ 'Don't change

unless required 770 LOWX = FALSE ++++ 'Don't change unless required 780 PRINT'Ia the transition CLEARLY

++++ slower near the high

++++ near the low?

":

than

790 GOSUB 1620 'Get response

800 IF ANSWR$ = 'Y" THEN HIGHX

= TRUE I ++++ GOT0 840 'Aberrations 810 PRINT'Is the

transition CLEARLY ++++ slower near the low than ++++ near the high?

": 820 GOSUB 1620 830 IF ANSWR$ = 'Y- THEN LOWX

= TRUE 840 'Aberrations 850 PRINT"Do both high and low levels ++++ have less than 5%' 860 PRINT' overshoot, undershoot, ++++

tilt

or other aberration?

l ;

in

a

A-12

24X5Al2467 Instrument Interfacing Guide

Appendix A

++tt

070 GOSUB 880

tilt

or

other aberration?

1620

IF

ANSWR$ = 'Y' THEN

":

t++t GOT0 990 'Measure 890 PRINT"Does the high level have lass ++tt

than 5%"

900 PRINT' overshoot, undershoot, tilt t+tt or other aberration? '; 910 GOSUB 1620 920 IF ANSWR$ <> "Y" THEN HIGHX = TRUE

930 IF ANSWR$ = "Y' THEN LOWX = TRUE t tt+t GOT0 990 'Measure 940 PRINT"Does the low level have less +ttt

than 5%" 950 PRINT" overshoot, undershoot. tilt t+tt or other aberration?

960

GOSUB

970

IF ANSWRS <> 'Y" THEN LOWX = TRUE

1620

";

980 ' 990 'Measurement Routine 1000 PRINT" -- Wait ror

+ttt iterative measurements. --•

1010 IF HIGHX=FALSE AND LOWX=FALSE AND it++ ACTUAL>0 THEN HIGHX=TRUE 1020 IF HIGHX=FALSE AND LOWX=FALSE AND

++++ ACTUAL<0 THEN LOWX= TRUE

1030

GOSUB

1680

'Get peaks

1040 PKTOPK = HIPEAK-LOPEAK

+tt+ 'Find peak to peak 1050 BTRLEV$="btr lev: "+ STR$ (LOPEAK

tt++ t.S*PKTOPK)'Find

50%

level

1060 CALL IBWRT(~~OPE%,BTRLEV$)

tttt 'Send

1070

IF IBSTA%

50%

level to B trigger

-z 0 THEN 2360

1080 HLPREV = .8 ++++ 'Initialize loop variables 1090

SLOPE0 = .25 t-k++ 'Initial ratio of threshold/risetime 1100 RISEACCM = 0 1110 HLACCM = 0

1120 COUNT = 0

24X5A12467 Instrument Interfacing Guide A-13

Appendix A

1130 1140 1150 1160 1170 1180

++++

1190

++++

1200 1210 1220 1230

++++

1240 ++++ 1250 1260 1270 1280

1290 ++++ 1300 ++++ 1310

++++

++++ 1320

++++

1330

++++

1340 1350

++++

1360

++++

1370

++++

1380 1390

++++

RISETIME = 0

I

WHILE COUNT

COUNT COLOR 1.7 t PRINT COUNT:" ATRLEV$ =

< 20 'Iteration loop

= COUNT + 1

‘atr lev:.

+ STR$ (LOPEAK

.:

+ LOW'PKTOPK)

CALL IBWRT(SC~PE%,ATRLEV$)

'Send lor level to A-trigger

IF IBSTA% < 0 THEN 2360 GOSUB 2020 'Get 1st delay reading DELAY1

= VAL (RD$)

ATRLEV$ = "atr lev:. + STR$(L~PEAK

+ HIGH'PKTOPK)

CALL IBWRT (SCOPE%,ATRLEV$)

'Send high level to A-trigger

IF IBSTA% < 0 THEN 2360 GOSUB 2020 'Get 2nd delay reading DELAY2 = VAL (RD$) RISEPREV = RISETIME RISETIME

= DELAY1 - DELAY2

'Delay difference

IF RISETIME/ACTUAL>.99 AND

RISETIME/ACTUAL<l.Ol THEN 1480

IF COUNT > 1 THEN RISEACCM =

RISEACCM + ABS ((RISETIME

- RISEPREV)/RISETIME)

IF COUNT > 1 THEN HLACCM

= HLACCM

+ AB~((HIGH - LOW -

HLPREV)/ (HIGH-LOW))

IF HLACCM > .02 THEN SLOPE0 =

HLACCM/RISEACCM

SLOPE = SLOPE0

IF HIGHX = TRUE AND LOWX = TRUE

THEN SLOPE = SLOPE/2

CHANGE=(HIGH-LOW)* (ACTUAL~RI~ETIME

- l)*SLOPE

IF HLPREV>.95 AND HIGH =.98 AND

=.02 THEN 1480

LOW

HLPREV = HIGH - LOW

IF HIGHX = TRUE THEN HIGH =

HIGH + CHANGE

A-l 4 24X5N2467 Instrument Interfacing Guide

Appendix A

1400

++++

1410 1420 1430

++++

1440 1450 1460 1470 1480

1490

++++

1500

++++

1510 1520 1530 ++++ 1540

++++ ++++

1550 1560

++++

1570

1580

++++ ++++ ++++ ++++ 1590 +-I-++

1800 1610 1620

++++

1630

++++

1640 1650

++++

IF LOWX = TRUE THEN LOW =

LOW - CHANGE IF HIGH > .98 THEN HIGH = .98 IF LOW

IF (LOW +'.;p2

THEN LOW = .02

> HIGH THEN 1480

'Finish Invalid "actual' IF HIGH = .98 THEN LOWX = TRUE IF LOW = .02 THEN HIGHX = TRUE

WEND

‘

'End

iteration

'Finish

COLOR 7,0 I PRINT I PRINT

COUNT:"

ITERATIONS"

PRINT"Use these new values for high

and low rith similar signals..

PRINT" New value for high = ':HIGH PRINT' PRINT"Measured

ir Negative)=

IF COUNT > 19 THEN

New

value

iOr

lor = ";LOW

Rise Time (Fall Time

";RISETIME

COLOR

15.4.0:

PRINT “Verify Risetime

measurement value." I COLOR 7.0 PRINT PRINT "Entered (target)

Transition

Time = ':ACTUAL

PRINT

IF ((HIGH-LOW < .2) OR (HIGH = .98

AND LOW =

COLOR 15.4 I PRINT"

.02)) THEN

..#..

ENTERED

TRANSITION TIME OUT OF RANGE

**#y*r.

PRINT"-- Enter

I COLOR 7.0

'run' to do another

threshold optimization."

GOT0 2400'End Routine

1---------------------------------'Subroutine to Wait for, Receive

and Print Response

ANSWR$ = INKEY$ i IF ANSWR$ =

"' THEN

1630

IF ANSWR$ = lym THEN ANSWR$ = .Y. IF ANSWR$ = 'Y" THEN PRINT .YES"

ELSE PRINT "NO"

loop

24X5A/2467 lnstrurnent Interfacing Guide A-15

Appendix A

1660 1670

1680

1690 1700 1710

1720 1730 ++++

1740

1750

1760 1770 ++++

1780

1790 1800 1810

1820 ++++ 1830 ++++ 1840 1850 ++++ 1660 1870

++++

1880 1890

1900

++++

1910 1920 1950 1940 1950 1970 1980 1990

++++

2000 ++++

RETURN

1_____----,------------------------

'Subroutine Get peaks ATRINITSOS = "atr init50. ATRQUER$ = 'atr? trigd" ATRPEKSS = 'atr?

max,mini.

I

'Set A-trigger

to INIT @ 50% for

peak measurement cycle

CALL IBwRT (SCOPE%,ATRINITSO$)

IF IBSTA%

< 0

THEN

2360

SENTLEV=TIMER 'START TIMER

CALL IBWRT (scoPE%,ATRQUER$)

'Ask if trigger found

IF IBSTA%

= SPACES (95)

RDO

< 0 THEN 2360

CALL IBRD(SCOPE%,RD$)

IF IBSTA% < 0 THEN 2360 IF MIDS (RD$,INSTR(~,RD$,":~)

+1,2)=“ON”

THEN 1890 'Found

IF SENTLEV +20>TIHER THEN 1770

'Under

20

seconds,

try COLOR 15.4 PRINT"

PRINT"

**g.*

FAULTY

MEASUREMENT

20

SECOND TIMEOUT"

*I#**.

PEAK VOLTAGE

PRINT'Check settings and

‘run’

to try again."

GOT0 2400'End Routine

1

Found

' Ask instrument

peaks by A-trigger

query

CALL IBWRT (sc~PE%,ATRPEKS$) IF IBSTA% < 0 THEN 2360

RD$=SPACE$ (95)

CALL IBRD(SCOPE%,RD$) IF IBSTA%

< 0 THEN 2360

IF IBSTA% < 0 THEN 2360

'Extract high and low

HIPEAK

= VAL (MIDS (RDS,INSTR (1,~~s.

":.)+l,lO))

LOPEAK

= VAL(MID$ (RDS,INSTR(~O.RD$.

'r')+l))

tri3

again

for

peaks

A-16 24X5A12467 Instrument Interfacing Guide

Appendix A

2010 2020

2030 ++++ 2040

++++

2050

++++ 2060 ++++ 2070 ++++ 2060 ++++ 2090 2100 ++++ 2110 2120 2130 2140 2150 ++++

2160 2170 2180 2190 2200 ++++ 2210 ++++ 2220 2230 2240 2250 ++++

2260 2270 ++++ 2280 2290 ++++

RETURN

I-------------------------------------' Get count Subroutine (equivalent

to GETCTTN subroutine)

CTTRSET$ = 'ctt reset' 'These 4 lines

should appear early in

CTRQUERS = "ctr?' 'the main

program: they are shown

CTSQUERS = 'ots?'

'to indicate

here

the actual string values

EVENT$ = "event?'

'required by the scope.

CALL IBWRT (SCOPE%,CTTRSET$)

'Discard stale measurements IF IBSTA% < 0 THEN 2360 CALL IBWRT (SCOPE%,CTRQUER$)

'Measurement

available?

IF IBSTA% < 0 THEN 2360

RD$=SPACE$ (95)

CALL IBRD (SCOPE%,RD$) IF IBSTA% < 0 THEN 2360

CALL IBWRT (sCOPE%,EVENT$)

'Event

query

IF IBSTA% < 0 THEN 2360

EV$=SPACE$ (20) CALL IBRD (SCOPE%,EV$)

IF IBSTAZ < 0 THEN 2360 IF VAL(MID$ (EV$.INSTR (~,Ev$."

m)+l))

<> 0 THEN 2280

IF VAL (RD$) = 0 THEN 2100

'No measurement

available CALL IBWRT (SCOPE%,CTSQUER$) IF IBSTA% < 0 THEN 2360

RD$=SPACE$ (95) CALL IBRD (SC~PE%.RDS)

'Get reading from scope IF IBSTA% < 0 THEN 2360 IF VAL (RD~) < lE+09 THEN RETURN

' >=

l.Oe+9 indicates error COLOR 15.4 'Print error message PRINT*

COUNTING MEASUREMENT

..#..

FAULTY TIME OR

**#**.

24X5A12467 Instrument Interfacing Guide A-l 7

Appendix A

2300 2310 ii++ 2320 ii++ 2330 2340 2350 2360 2370 ii++ 2380 ii++ ++++ ++++ 2390 2400

2410

2420 ++++ 2430

PRINT"Error PRINT'

cod0

Check scope settings and

signal source .'

COLOR 7,0

I PRINT"-----

Enter 'run' to try again.

COT0 2400'End Routine

(___-__-__---------------_--------'Incorrect

= HEX$ (IBSTA%)

S$

symbolic name or address

PRINT ' IBSTA = l ;S$;IBCNT =

";IBCNT%;IBERR = ';IBERR%

IF S$="SOOO"

";SCOPE$;'

is not a valid name."

ELSE PRINT" l ;SCOPE$;" is not

correctly addressed."

)-_-----------------------------'End

Routine V% = 0 t CALL IBONL (SCOPE%,V%) COLOR 7.0 I KEY ON : CALL

IBLOC (SCOPE%)

END

':VAL (RDS);

I COLOR 15,4

THEN PRINT'

HP 98XX Program to Calibrate Trigger Levels for

Transition Time

10 ! A BASIC Program for the

-I-+++ Hewlett Packard 98XX 20 !to Adjust ++++ Transition Time Measurements 30 ! with the Tektronix ++++ 24X5A and 2467 Oscilloscopes. 40 ! 30 June 1686 50 GOSUB Setup ++++ !Initialfze and setup crt 60 ! 70 !Use this program only for system ii++ setup and calibration. 80 ! 'NOTE: ++++ number indicates that 90 !' separately printed ++++ must be joined. The

Trigger Thresholds for

" ++++. in place of a line

lines

l ++++.

--w-s"

A-18

24X5A/2467 Instrument Interfacing Guide

Appendix A

100

110 ++++ 120

++++

150 140 150

++++

160

170 ++++ 180 ++++ 190 ++++

200 210 ++++ 220 ++++ 230 ++++ 240 ++++ 250

260 ++++

270 ++++

280 ++++ 290 ++++ 300

++++

310

320 ++++ 330 ++++

! ’

PRINT 'Execute this

symbols must not be entered.

procedure

program to rind"

PRINT 'optimum high and low

thresholds for transition" PRINT " time measurements.* PRINT PRINT "Repeat the procedure to

optimum thresholds"

PRINT " for each dissimilar signal." PRINT "1. Connect oscilloscope

to controller IEEE-488 bus."

PRINT "2.

transition

Carefully

time

measure

with

cursors..

PRINT . Use 10% and 90% or

20% and 80% or other"

PRINT ' appropriate

PRINT "3. Manually set

to measure

the transi-"

levels.w

the

PRINT " tion of interest, with

the same control setting"

PRINT " that will be used in

the automatic test.

PRINT

l

gaMeasuring Rise and

Review"

Fall Times"' to determine' PRINT " the best settings.a PRINT "4. Enter the transition

time measured in step

PRINT " in exponential

ei3.

5.433-g <ENTER>."

2,”

form,

PRINT " fall time is minus,

-29.6E-6 <ENTER>."

w3.

CALL Check-communi(D2465)

!Check bus to scope

LOCAL PRINT "Transition Time:

02465 !User sets

scope

UP

";

LINPUT Actual$ !E or e

accepted

Actual=VAL (UPCS (Actual$))

!Converts e to E

and

find

scope

24X5A/2467 instrument Interfacing Guide

A-19

Tektronix 2467 Instrument Interfacing Guide

Specifications and Main Features

Frequently Asked Questions

User Manual