2
PW3335A985-01
Message Format
Program Messages
Program messages can be either Command Messages or Query Messages.
(1) Command Messages
Instructions to control the instrument, such as to change settings or reset
Example: Instruction to set the voltage range.
:VOLTAGE:RANGE 300
Header portion
Space Data portion
(2) Query Messages
Requests for responses relating to results of operation or
measurement, or the state of instrument settings
Example: Request for the current measurement range
:VOLTAGE:RANGE?
Header portion
Question mark
See:
"Headers (p. 2)", "Separators (p. 3)", "Data Formats (p.4)"
Response Messages
When a query message is received, its syntax is checked and a response message is generated.-
The
command determines whether headers are prefixed to response messages.
Header
ON
:VOLTAGE:RANGE 300
Header OFF
300
(The current voltage range is 300 V.)
At power-on, Header ON is selected.
If an error occurs when a query message is received, no response message is generated for that query.
Command Syntax
Command names are chosen to mnemonically represent their function, and can be abbreviated. The full
command name is called the “long form”, and the abbreviated name is called the “short form”. The
command references in this manual indicate the short form in upper-case letters, extended to the long form
in lower case letters, although the commands are not case-sensitive in actual usage.
DISPLAY?
OK ( long form )
DISP?
OK ( short form )
DISPL?
Error
DIS?
Error
Response messages generated by the instrument are in long form and in upper case letters.
Headers
Headers must always be prefixed to program messages.
(1) Command Program Headers
There are three types of commands: Simple, Compound, and Standard.
•
Headers for Simple Commands
This header type is a sequence of letters and digits.
:ESE0
•
Headers for Compound Commands
These headers consist of multiple simple command type headers separated by colons ":".
:VOLTage:RANGE
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