Keysight Technologies U1281A, U1282A Programming Manual

Keysight U1281A/U1282A
Handheld Digital Multimeter

Programming
Guide

Notices

CAUTION

WARNING

© Keysight Technologies 2015

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Manual Part Number

U1281-90001

Edition

Edition 1, July 22, 2015

Printed in Malaysia

Keysight Technologies
Bayan Lepas Free Industrial Zone,
11900, Penang, Malaysia

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2 Keysight U1281A/U1282A Programming Guide

Table of Contents

1 Introduction

Configuring the IR interface 6

Introduction to Remote Commands 7

2 Remote Commands

U1281A/U1282A Configuration Overview 12

*IDN? 13

*RST 14

*CLS 15

ABOR 16

CALC:AVER 17

CALC:PEAK 18

CONF? 19

FETC? 20

INIT 21

READ? 22

STAT? 23

SYST:BATT? 26

TRIG:SOUR 27

TRIG:REF:COUN 28

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4 Keysight U1281A/U1282A Programming Guide

Keysight U1281A/U1282A
Handheld Digital Multimeter

Programming Guide

1 Introduction

Configuring the IR interface 6
Introduction to Remote Commands 7

Syntax conventions 7
Querying parameter settings 8
Returned result 8
Prompts 8

This chapter describes the parameters that configure the U1281A/U1282A, and helps you
determine the settings to achieve optimum performance.

1Introduction

NOTE

Configuring the IR interface

The U1281A/U1282A may be operated via an IR interface. The remote control operation
will enable you to manually operate the multimeter via a terminal, or to automatically
execute a host computer program.

The default parameters for the U1281A/U1282A are:

–Baud rate : 9600 bits per second

– Parity bit : None

– Data bits : 8 data bits

– Number of Stop Bits : 1 bit

Ensure that the serial port terminator to CR/LF is configured for both the transmit and
receive settings.

– The Carriage Return (CR) character (0x0D, \r) moves the cursor to the beginning of the

line without advancing to the next line. This character is used as a new line character in
Commodore and Early Macintosh operating systems (OS-9 and earlier).

– The Line Feed (LF) character (0x0A, \n) moves the cursor down to the next line without

returning to the beginning of the line. This character is used as a new line character in
UNIX-based systems (Linux, Mac OS X, etc.).

– The End Of Line (EOL) sequence (0x0D0x0A, \r\n) is actually two ASCII characters—a

combination of the CR and LF characters. It moves the cursor both down to the next
line and the beginning of that line. This character is used as a new line character in
most other non-Unix operating systems including Microsoft Windows, Symbian OS, and
others.

Each time after a *RST command is sent to the U1281A/U1282A, the communication
buffer (transmit and receive) must be cleared before the next command is sent.

In order to ensure smooth communication, allow sufficient time for the U1281A/U1282A to
respond to each command. In most cases, this means refers to a 5-second delay after the
*RST command and a 200-millisecond delay for all other commands.

For situations where the above delay is insufficient and is related to the serial port
hardware, operating system (OS) serial communication buffer, or the central processing
unit (CPU) response time, you may consider increasing the delay time to maintain stable
communication with the U1281A/U1282A.

6 Keysight U1281A/U1282A Programming Guide

Introduction to Remote Commands

Remote commands control instrument functions. A subsystem command has a hierarchical
structure that usually consists of a top-level (or root) keyword, one or more lower level
keywords, and parameters. The following example shows a query and its associated
subsystem:

-> CALC:AVER:MAX?

CALC is a root level keyword with AVER as the second level keyword, and MAX as the

third-level keyword.

Syntax conventions

Throughout this programming guide, the following conventions are used for remote
command syntax:

– Square brackets “[ ]” indicate optional keywords or parameters and can be omitted. The

brackets are not sent with the command string. If you do not specify a value for an
optional parameter, the instrument chooses a default value.

– Braces “{ }” enclose one or more parameters that may be included zero or more times.

The brackets are not sent with the command string.

– Triangle brackets “< >” indicate that you must substitute a value for the enclosed

parameter. The brackets are not sent with the command string.

– Parentheses “( )” enclose parameters that are usually a channel list.

Introduction 1

– Vertical bars “|” can be read as “or” and are used to separate alternative parameter

options.

Only short form commands are recognized by the instrument. For example, consider the
keyword TRIGger. Only the short form—which is TRIG—will be recognized by the
instrument. Other forms, such as TRIGG, TRIGge, or even TRIGger, will generate errors. An
example of the command syntax format is illustrated below:

-> TRIG:SOUR <BUS|REF|IMM>

Keysight U1281A/U1282A Programming Guide 7

1Introduction

Querying parameter settings

You can query the current value of most parameters by adding a question mark (?) to the
command. For example, you can query the function of the primary display measurement by
sending:

-> CONF?

Responding Message

Returned result

After the U1281A/U1282A executes a query command, the return of the result will be in the
following format:

<- <Result> + <CR> <LF>

On the multimeter warning the returned prompts will be in the following format except Xon
and Xoff:

<- <Prompts> + <CR> <LF>

Prompts

The U1281A/U1282A will generate a system warning by sending a prompt string to the
host through the remote interface when the U1281A/U1282A has a status change as listed
in the table below.

Prompt Description

﹡ L

﹡ C

﹡ E

﹡ B

﹡ I

﹡ 0

﹡ 1

﹡ 2

﹡ 3

﹡ 4

8 Keysight U1281A/U1282A Programming Guide

Local mode

Calibration mode

Remote command error warning

Low battery warning

Input warning (Please refer to STAT? command)

Rotary position: ACV measurement

Rotary position: ACmV measurement

Rotary position: ACDCV measurement

Rotary position: ACDCmV measurement

Rotary position: RES/CONT measurement

Prompt Description

﹡ 5

﹡ 6

﹡ 7

﹡ 8

﹡ 9

ASC(&H11) Xon: The meter is available

ASC(&H13) Xoff: The meter is busy

Rotary position: Diode/Hz measurement

Rotary position: CAP/TEMP measurement

Rotary position: uA/mA measurement

Rotary position: A measurement

Rotary position: SQU output

Introduction 1

Keysight U1281A/U1282A Programming Guide 9