SIGLENT
SSA3000X Programming Guide 7
2.SCPI Overview
2.1 Command Format
SCPI commands present a hierarchical tree structure containing multiple subsystems, each
of the subsystems is made up of a root keyword and several subkeywords. The command
string usually starts with “:”, the keywords are separated by “:”and the followed parameter
settings are separated by space. Query commands add “?”at the end of the string.
For example:
:SENSe:FREQuency:CENTer <freq>
:SENSe:FREQuency:CENTer?
SENSe is the root key of the command, FREQuency and CENTer are second and third
keywords. The command begins with “:”, and separates the keywords at the same time,
<freq> separated by space and represents the parameter available for setting; “?”represents
a query.
2.2 Symbol Instruction
The following four symbols are not the content of SCPI commands and can not be sent with
the commands, but are usually used in the commands.
1, Triangle Brackets < >
The parameter in the triangle brackets must be replaced by an effective value. For example:
Send the “:DEMod:VOLume <value>”command in “:DEMod:VOLume 5”.
2, Square Brackets [ ]
The content in the square brackets can be ignored. When the parameter is ignored, the
instrument will set the parameter to its default. For example,
In the “[:SENSe]:POWer[:RF]:ATTenuation?”command, sending any of the four commands
below can generate the same effect:
:POWer:ATTenuation?
:POWer:RF:ATTenuation?
:SENSe:POWer:ATTenuation?
:SENSe:POWer:RF:ATTenuation?
3, Vertical Bar |
The vertical bar is used to separate multiple parameters and when sending the command,
you can choose one of the parameters. For example,
In the “[:SENSe]:FREQuency:CENTer:STEP:AUTO OFF|ON|0|1”command, the parameters
available are “OFF”, “ON”, “0”or “1”.
4, Braces { }
The parameters in the braces are optional which can be ignored or set for one or more times.
For example:
:CALCulate:LLINe[1]|2:DATA <x-axis>,<ampl>{,<x-axis>, <ampl>}, in the command, the {,<x-
axis>, <ampl>} parameters can be ignored or set for one or more times.