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Structure and Syntax of the Device Messages R&S FSMR
1166.3363.12 5.10 E-1
Device-specific commands
Hierarchy
: Device-specific commands are of hierarchical structure (see
Fig. 5-1). The different levels are represented by combined headers.
Headers of the highest level (root level) have only one key word. This
key word denotes a complete command system.
Example:
SENSe
This key word denotes the command system
SENSe
.
For commands of lower levels, the complete path has to be specified,
starting on the left with the highest level, the individual key words being
separated by a colon ":".
Example:
SENSe:FREQuency:SPAN 10MHZ
This command lies in the third level of the SENSe system. It set the
frequency span.
SENSe
BANDwidth FUNCtion
FREQuency
STOP CENTer SPAN OFFSet
STARt
DETector
Fig. 5-1 Tree structure the SCPI command systems using the SENSe system by way of example
Some key words occur in several levels within one command system. Their
effect depends on the structure of the command, that is to say, at which
position in the header of a command they are inserted.
Example:
SOURce:FM:POLarity NORMal
This command contains key word POLarity in the third
command level. It defines the polarity between modulator and
modulation signal.
SOURce:FM:EXTernal:POLarity NORMal
This command contains key word POLarity in the fourth
command level. It defines the polarity between modulation
voltage and the resulting direction of the modulation only for the
external signal source indicated.