Keysight U1281A/U1282A
Handheld Digital Multimeter
Programming
Guide
Notices
CAUTION
WARNING
© Keysight Technologies 2015
No part of this manual may be reproduced
in any form or by any means (including
electronic storage and retrieval or
translation into a foreign language)
without prior agreement and written
consent from Keysight Technologies as
governed by United States and
international copyright laws.
Manual Part Number
U1281-90001
Edition
Edition 1, July 22, 2015
Printed in Malaysia
Keysight Technologies
Bayan Lepas Free Industrial Zone,
11900, Penang, Malaysia
Warranty
THE MATERIAL CONTAINED IN THIS
DOCUMENT IS PROVIDED "AS IS," AND
IS SUBJECT TO BEING CHANGED,
WITHOUT NOTICE, IN FUTURE EDITIONS.
FURTHER, TO THE MAXIMUM EXTENT
PERMITTED BY APPLICABLE LAW,
KEYSIGHT DISCLAIMS ALL WARRANTIES,
EITHER EXPRESS OR IMPLIED WITH
REGARD TO THIS MANUAL AND ANY
INFORMATION CONTAINED HEREIN,
INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE. KEYSIGHT
SHALL NOT BE LIABLE FOR ERRORS OR
FOR INCIDENTAL OR CONSEQUENTIAL
DAMAGES IN CONNECTION WITH THE
FURNISHING, USE, OR PERFORMANCE
OF THIS DOCUMENT OR ANY
INFORMATION CONTAINED HEREIN.
SHOULD KEYSIGHT AND THE USER
HAVE A SEPARATE WRITTEN
AGREEMENT WITH WARRANTY TERMS
COVERING THE MATERIAL IN THIS
DOCUMENT THAT CONFLICT WITH
THESE TERMS, THE WARRANTY TERMS
IN THE SEPARATE AGREEMENT
WILL CONTROL.
Technology Licenses
The hardware and/or software described
in this document are furnished under a
license and may be used or copied only in
accordance with the terms of
such license.
Restricted Rights Legend
If software is for use in the performance of
a U.S. Government prime contract or
subcontract, Software is delivered and
licensed as "Commercial computer
software" as defined in DFAR
252.227-7014 (June 1995), or as a
"commercial item" as defined in FAR
2.101(a) or as "Restricted computer
software" as defined in FAR 52.227-19
(June 1987) or any equivalent agency
regulation or contract clause. Use,
duplication or disclosure of Software is
subject to Keysight Technologies'
standard commercial license terms, and
non-DOD Departments and Agencies of
the U.S. Government will receive no
greater than Restricted Rights as defined
in FAR 52.227-19(c)(1-2) (June 1987).
U.S. Government users will receive no
greater than Limited Rights as defined in
FAR 52.227-14 (June 1987) or DFAR
252.227-7015 (b)(2) (November 1995), as
applicable in any technical data.
Safety Notices
A CAUTION notice denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like that, if not correctly
performed or adhered to, could
result in damage to the product or
loss of important data. Do not
proceed beyond a CAUTION notice
until the indicated cond itions are
fully understood and met.
A WARNING notice denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like that, if not correctly
performed or adhered to, could
result in personal injury or death.
Do not proceed beyond a
WARNING notice until the
indicated conditions are fully
understood and met.
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
Keysight U1281A/U1282A Programming Guide 3
THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.
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
1Introduction
THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.
10 Keysight U1281A/U1282A Programming Guide
Keysight U1281A/U1282A
NOTE
NOTE
Handheld Digital Multimeter
Programming Guide
2 Remote Commands
*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
This chapter describes the U1281A/U1282A remote commands.
Ensure that you have configured the U1281A/U1282A before using any of the remote
commands. Refer to “U1281A/U1282A Configuration Overview” on page 12. For more
details, refer to the U1281A/U1282A User’s Guide.
Due to the unique Export Log feature of the U1281A/U1282A, you will need to handle the
exporting of data when using any of the following functions:
– Trigger Hold
–Auto Hold
– Manual Log
– Interval Log
– Event Log
–Export Log
When you send a command related to any of the above functions, the U1281A/U1282A will
return additional information on export log data. If this is not handled properly, it will cause
wrong data to be fetched and an exception error to occur. Therefore to always ensure
correct data is fetched, it is recommended not to use the above functions during
programming.
2 Remote Commands
A
mA
COM
V
V
A
V
mV
mV
U1282A
True RMS Multimeter
mA
Vsense
Peak
Vsense
Dual
Auto
FUSED
440mA
CAT III 1000V
600VCAT IV
MAX
10A MAX
FUSED
OUT
OUT
MHz
RMT
3
1
2
Use the keypad to configure measurement
settings.
Turn the rotary switch to the desired
measurement function.
Connect the test leads to the appropriate
input terminals according to the selected
measurement function.
U1281A/U1282A Configuration Overview
When the above configuration has been made, you can proceed to use the remote
commands in the following sections.
12 Keysight U1281A/U1282A Programming Guide
*IDN?
Remote Commands 2
Syntax
*IDN?
Description
The *IDN? query allows the U1281A/U1282A to identify itself by returning the model
number, serial number, and the firmware version. The string returned is, for example:
Keysight Technologies,<model number>,<serial number>,VXX.xx
where:
– <model number> identifies which U1281A/U1282A model is being used.
– <serial number> uniquely identifies each U1281A/U1282A.
– VXX.xx represents the firmware revision with XX and xx representing the major and
minor revisions respectively.
Example
-> *IDN?
<- Keysight Technologies,U1282A,DPQ1007000,V1.00
Keysight U1281A/U1282A Programming Guide 13
Returns the model number, serial number,
and the firmware version of the multimeter.
2 Remote Commands
*RST
Syntax
*RST
Description
The *RST (reset) command places the U1281A/U1282A in the power-on-reset state without
shutting down the line power and returns the current rotary knob position (refer to
“Prompts” on page 8 for a legend on rotary knob positions). The interface parameters will
return to their default values (refer to “Configuring the IR interface” on page 6 ).
Example
-> *RST
<- *1
Places the instrument in the power-on-reset
state and returns the instrument to the
ACmV rotary switch position.
14 Keysight U1281A/U1282A Programming Guide
*CLS
Remote Commands 2
Syntax
*CLS
Description
The *CLS (clear status) command clears the event registers in all register groups. This
command also clears the Error queue.
Example
-> *CLS
The following command clears the event
register bits.
Keysight U1281A/U1282A Programming Guide 15
2 Remote Commands
ABOR
Syntax
ABOR
Description
This command places the trigger hold system in the idle state.
The display will show a dash (–) until the INIT command is triggered.
Example
-> ABOR Places the trigger hold mode in the idle state
Remarks
This command is only available in trigger hold mode.
16 Keysight U1281A/U1282A Programming Guide
CALC:AVER
Query
Description
Example
Remote Commands 2
CALC:AVER:MAX|MIN|AVER|PRES|COUN?
This query returns the value of the specific dynamic recording function.
– MAX returns the maximum recorded value
– MIN returns the minimum recorded value
– AVER returns the average recorded value
– PRES returns the present recorded value
– COUN returns the count value of the average mode
-> CALC:AVER:MAX? Returns the maximum recorded value
<- +2.63782000E+00
Keysight U1281A/U1282A Programming Guide 17
2 Remote Commands
CALC:PEAK
Query
CALC:PEAK:MAX|MIN?
Description
This query returns the value of the peak-hold function.
– MAX returns the maximum recorded value
– MIN returns the minimum recorded value
Example
-> CALC:PEAK:MAX? Returns the maximum peak-hold value
<- +2.83752000E+00
18 Keysight U1281A/U1282A Programming Guide
CONF?
Remote Commands 2
Query
CONF? [@2]
Description
This query returns a series of comma-separated fields indicating the present measurement
function of the primary or secondary display.
The query is returned in the following format string: <“Function”, “Range”,
“Resolution”>.
When the @2 parameter is omitted, the query returns the function of the primary display.
Example
-> CONF? Returns the function of the primary display
<- VOLT:AC +6.00000000E+01,+1.00000000E-03
Keysight U1281A/U1282A Programming Guide 19
2 Remote Commands
FETC?
Syntax
FETC? [@2|@3]
Description
This query returns the value of the primary or secondary display.
When the @2 parameter is omitted, the query returns the value of the primary display.
The @3 parameter corresponds to the environment temperature.
Example
-> FETC? Returns the value of the primary display.
<- +1.23475000E+00
20 Keysight U1281A/U1282A Programming Guide
INIT
Remote Commands 2
Syntax
INIT
Description
This command removes the trigger hold system from the idle state and re-triggers the
system.
Example
-> TRIG:SOUR:BUS Enters the trigger hold mode.
Remarks
-> INIT
-> FETC? Returns the value of the primary display.
<- +1.23266000E+00
This command is only available in trigger hold mode.
Removes the trigger hold mode from the idle
state and re-triggers the system.
Keysight U1281A/U1282A Programming Guide 21
2 Remote Commands
READ?
Syntax
READ?
Description
This query returns a value after the re-trigger cycle when in the trigger hold mode.
When not in the trigger hold mode, this query returns the display value.
Example
-> TRIG:SOUR:BUS Enters the trigger hold mode.
-> READ?
<- -1.20000000E-01
Returns a value after the re-trigger cycle
when in the trigger hold mode, or the display
value when not in the trigger hold mode.
22 Keysight U1281A/U1282A Programming Guide
STAT?
Syntax
STAT?
Description
This query returns the status of the U1281A/U1282A in the following format string:
<ABCDEFGHIJKLMNOPQRSTU>
Each of the letters represented in the format string are explained below:
Letter Parameter Description
A Average function
B Null function
CdB function
D Terminal alert
E Peak-hold function
F Current percent
G Pulse width and duty trigger level
H Trigger Hold function
I
0 oC temperature compensation
Remote Commands 2
0 : Off
1 : On
0 : Off
1 : On
0 : Off
M : dBm
V : dBV
0 : Off
1 : On
0 : Off
1 : On
0 : Off
1 : 4-20 mA
2 : 0-20 mA
0 : Negative
1 : Positive
0 : Off
1 : On
0 : Off
1 : On
Keysight U1281A/U1282A Programming Guide 23
2 Remote Commands
Letter Parameter Description
J Beep initial driving frequency
K Auto power-off status
L Auto Hold function
M Meter mode
N Voltage alert
O Reserved For future use
P Rotary position
Q Battery type
R Battery level
S Resolution
T AC Low Pass Filter status
U DC Filter status
0 : Off
1 : 3200 Hz
2 : 3268 Hz
3 : 3339 Hz
4 : 3413 Hz
5 : 3491 Hz
6 : 3572 Hz
7 : 3657 Hz
8 : 3746 Hz
9 : 3840 Hz
A : 3938 Hz
B : 4042 Hz
C : 4151 Hz
D : 4267 Hz.
0 : Off
1 : On
0 : Off
1 : On
L : Normal
C : Calibration
0 : Off
1 : On
0 : ACV measurement
1 : ACmV measurement
2 : ACDCV measurement
3 : ACDCmV measurement
4 : Ω/nS measurement
5 : Diode measurement
6 : CAP/temperature measurement
7 : μA/mA measurement
8 : Current measurement
9 : SQU output
0 : Primary
1 : Secondary (rechargeable)
0 : Normal
1 : Low
0 : Five decimal places
1 : Four decimal places
0 : Off
1 : On
0 : Off
1 : On
24 Keysight U1281A/U1282A Programming Guide
Example
Remote Commands 2
-> STAT? Returns the status of the U1281A/U1282A
<- 000000000910L00200000
Keysight U1281A/U1282A Programming Guide 25
2 Remote Commands
SYST:BATT?
Syntax
SYST:BATT?
Description
This query returns the residual capacity of the battery in the U1281A/U1282A.
Example
-> SYST:BATT?
<- 100%
Returns the residual capacity of the battery
currently in the U1281A/U1282A.
26 Keysight U1281A/U1282A Programming Guide
TRIG:SOUR
Syntax
Description
Parameters
Remote Commands 2
TRIG:SOUR <BUS|REF|IMM>
TRIG:SOUR?
This command is used to enter or exit the trigger hold mode or the auto hold mode.
The query returns the type of the trigger source.
Item Range of values Description
BUS Enters the trigger hold mode
character_data
REF Enters the auto hold mode
IMM
Exits either the trigger hold mode or the auto
hold mode
Example
-> TRIG:SOUR:REF Enters the auto hold mode.
-> TRIG:SOUR? Returns the type of the trigger source.
<- REF
Remarks
The average and peak functions are disabled when you enter either trigger hold mode or
auto hold mode.
Keysight U1281A/U1282A Programming Guide 27
2 Remote Commands
TRIG:REF:COUN
Syntax
TRIG:REF:COUN <numeric_value>
TRIG:REF:COUN?
Description
This command is used to set the auto hold mode count.
The query returns the auto hold mode count.
Parameters
Item Range of values Description
numeric_value
0 Enables the trigger hold mode
1 ~ 9999
Enables the auto hold mode
The default value is 50
Example
-> TRIG:REF:COUN 50 Sets a count of 50 to the auto hold mode.
-> TRIG:REF:COUN? Returns the auto hold mode count.
<- +5.00000000E+01
Remarks
The count will be stored in the non-volatile memory, but the “0” parameter will not.
28 Keysight U1281A/U1282A Programming Guide
This information is subject to change
without notice. Always refer to the
English version at the Keysight Web
site for the latest revision.
© Keysight Technologies 2015
Edition 1, July 22, 2015
*U1281-90001*
U1281-90001
www.keysight.com
Loading...