Rohde & Schwarz R&S FSL3 - Structure of a Command Line

R&S FSL SCPI Command Structure and Syntax
1300.2519.12 5.7 E-11
• Numeric suffix
I
f a device features several functions or features of the same kind, e.g. inputs, the desired function
can be selected by a suffix added to the command. Entries without suffix are interpreted like entries
with the suffix 1. Optional keywords must be specified if they select a function with the suffix.
Example: SYSTem:COMMunicate:SERial2:BAUD 9600
This command sets the baud rate of a second serial interface.
Note: In case of remote control, suffix counting may differ from the numbers of the corresponding
selection used in manual operation. SCPI prescribes that suffix counting starts with 1. Suffix 1 is
the default state and used when no specific suffix is specified.
Some standards define a fixed numbering, starting with 0. With GSM, for instance, slots are
counted from 0 to 7. In the case of remote control, the slots are selected with the suffixes 1 to 8.
If the numbering differs in manual operation and remote control, it is indicated with the
respective command.
Structure of a Command Line
A command line may consist of one or several commands. It is terminated by an EOI signal together
with the last data byte.
Several commands in a command line must be separated by a semicolon ";". If the next command
belongs to a different command system, the semicolon is followed by a colon. A colon ":" at the
beginning of a command marks the root node of the command tree.
Example:
CALL InstrWrite(analyzer, "SENSe:FREQuency:CENTer 100MHz;:INPut:ATTenuation
10")
This command line contains two commands. The first one is part of the SENSe command system and is
used to determine the center frequency of the instrument. The second one is part of the INPut
command system and sets the input signal attenuation.
If the successive commands belong to the same system, having one or several levels in common, the
command line can be abbreviated. For that purpose, the second command after the semicolon starts
with the level that lies below the common levels (see also Fig. 5–1). The colon following the semicolon
must be omitted in this case.
Example:
CALL InstrWrite(analyzer,
"SENSe:FREQuency:STARt 1E6;:SENSe:FREQuency:STOP
1E9")
This command line is represented in its full length and contains two commands separated from each
other by the semicolon. Both commands are part of the SENSe command system, subsystem
FREQuency, i.e. they have two common levels.
When abbreviating the command line, the second command begins with the level below
SENSe:FREQuency. The colon after the semicolon is omitted. The abbreviated form of the command
line reads as follows:
CALL InstrWrite(analyzer, "SENSe:FREQuency
:STARt 1E6;STOP 1E9")
However, a new command line always begins with the complete path.
Example:
CALL InstrWrite(analyzer, "SENSe:FREQuency:STARt
1E6")
CALL InstrWrite(analyzer, "SENSe:FREQuency:STOP 1E9")