Hierarchical Command Structure - Anritsu Site Master S331L Scpi Programming Manual

2-3 Subsystem Commands
Long Format vs. Short Format
Each keyword has a long format and a short format. The start frequency can be specified by
:SENSe:FREQuency:STARt or :SENS:FREQ:STAR. The capital letters in the command
specification indicate the short form of the command. A mixture of the entire short form
elements with entire long form elements of each command is acceptable. For example,
:SENS:FREQuency:STAR is an acceptable form of the command. However,
:SENS:FREQuen:STA is not an acceptable form of the command because :FREQuen is not the
entire short or long form of the command element.

Hierarchical Command Structure

All SCPI commands, except the common commands, are organized in a hierarchical structure
similar to the inverted tree file structure used in most computers. The SCPI standard refers
to this structure as "the Command Tree." The command keywords that correspond to the
major instrument control functions are located at the top of the command tree. The root
command keywords for the SCPI command set are shown in
:ABORt
:CALCulate
:CALibration
:CONFigure
:DISPlay
Figure 2-1. SCPI Command Tree
All instrument SCPI commands, except the :ABORt command, have one or more
subcommands (keywords) associated with them to further define the instrument function to
be controlled. The subcommand keywords may also have one or more associated
subcommands (keywords). Each subcommand level adds another layer to the command tree.
The command keyword and its associated subcommand keywords form a portion of the
command tree called a command subsystem. The :CONFigure command subsystem is
shown in Figure 2-2.
2-4
root
:FETCh :MEASure
:FORMat :MMEMory
:INITiate :READ
:INPut :SENSe
:INSTrument :SOURce
PN: 10580-00322 Rev. F
Chapter 2 — Programming with SCPI
Figure 2-1.
:STATus
:SYSTem
:TRACe
:TRIGger
:UNIT
[:SENSe]
S331L PM