Instructions

1
SCPI Introduction
SCPI (Standard Commands for Programmable Instrument) is a standard instruction set for programmable
devices under IEEE 488.2. SCPI commands are divided into two parts: IEEE 488.2 Common Commands
and SCPI Instrument Specific Control Commands.
Common commands are commands that the instrument specified in IEEE 488.2 must support. Its syntax
and semantics follow IEEE 488.2. Common commands are independent from the measurement and are
used to control reset, self-test and status inspection. For an introduction of SCPI common commands,
refer to the relative chapter below.
SCPI instrument-specific control commands are used to measure, read data, and toggle switches,
including all measurement functions and specific functions.。
Command Format
The SCPI command is a tree hierarchy that includes multiple subsystems, each consisting of a root key
and one or more level keys. The command line usually begins with a colon ":"; the keywords are
separated by the colon ":" followed by the optional parameter settings; the question mark "?" is added
after the command line to query this function; the commands and parameters separate with "space".
E.g
:CALCulate:BANDwidth:NDB <rel_ampl>
:CALCulate:BANDwidth:NDB?
CALCulate is the root keyword of the command, BANDwidth and NDB are the second level, third level
keywords. The command line starts with a colon ":" and at the same time separates keywords at all levels,
<rel_ampl> indicates configurable parameters; the question mark "?" indicates a query; the command:
CALCulate:BANDwidth:NDB and parameter <rel_ampl> "separate.
In some commands with parameters, it is common to use commas "," to separate the parameters, for
example:
:SYSTem:DATE <year>,<month>,<day>
Symbol Description
The following four symbols are not part of the SCPI command, but are usually used to assist in specifying
the parameters in the command.。
Brace { }
Parameters in brace are optional and can be set one or more times or even don’t set them. E.g: