Introduction to the SCPI Language
SCPI (Standard Commands for Programmable Instruments) is an ASCII-based programming language for
test and measurement instruments. SCPI commands use a hierarchical structure known as a tree system.
Associated commands are grouped under a common node or root, thus forming subsystems. A portion of
the SENSe subsystem illustrates this, below.
SENSe:
VOLTage:
DC:RANGe {<
range
>|MIN|MAX|DEF}
DC:RANGe? [MINimum|MAXimum|DEFault]
SENSe
is the root keyword of the command,
VOLTage
is a second-level keyword, and
DC
is a third-level
keyword. A colon (
:
) separates consecutive keywords.
Syntax Conventions
The command syntax format is illustrated below:
VOLTage:DC:RANGe {<
range
>|MIN|MAX|DEF}
Most commands (and some parameters) are a mixture of upper- and lower-case letters. The upper-case let-
ters indicate the command's abbreviated spelling, which yields shorter program lines. For better program
readability, use the long form.
For example, consider the keyword VOLTage, above. You can type VOLT or VOLTage in any combination of
upper- or lower-case letters. Therefore, VolTaGe, volt and Volt are all acceptable. Other forms, such as
VOL and VOLTAG, generate errors.
Braces (
{ }
) enclose the parameter choices. The braces are not sent with the command string.
A vertical bar (
|
) separates parameter choices. For example, {<
range
>|MIN|MAX|DEF} in the above com-
mand indicates that you can specify a numeric range parameter, or "MIN", "MAX" or "DEF". The bar is not
sent with the command string.
Angle brackets (
< >
) indicate that you must specify a value for the enclosed parameter. For example, the
above syntax statement shows the <
range
> parameter in angle brackets. Do not send the brackets with
the command string. You must specify a value for the parameter (for example "VOLT:DC:RANG 10") unless
you select one of the other options shown in the syntax (for example "VOLT:DC:RANG MIN").
Optional parameters are enclosed in square brackets (
[ ]
). The brackets are not sent with the command
string. If you do not specify a value for an optional parameter, the instrument uses a default value.
Keysight True
volt
Series Operating and Service Guide
195
SCPI Programming Reference
