R&S AFQ100A
SCPI Command Structure and Syntax
1401.3084.32 5.19
E-3
Responses to Queries
A query is defined for each setting command unless explicitly specified otherwise. It is formed by adding
a question mark to the associated setting command. According to SCPI, the responses to queries are
partly subject to stricter rules than in standard IEEE 488.2.
1. The requested parameter is transmitted without header.
Example:
DIAGnostic:POINt:CATalog?
Answer:
DIAG_GND,DIAG_P5V,DIAG_P3V3,...
2. Maximum values, minimum values and all further quantities, which are requested via a special text
parameter are returned as numerical values.
Example:
SOURce:TRIGger:OUTPut3:DELay:MAXimum?
Answer:
4000
3. Boolean values are returned as 0 (for OFF) and 1 (for ON).
Example:
OUTPut:STATe?
Answer (for ON):
1
4. Text (character data) is returned in a short form.
Example:
SOURce:OUTPut:ANALog:TYPE?
Answer (for BALanced):
BAL
Parameters
Most commands require a parameter to be specified. The parameters must be separated from the
header by a 'white space'. Permissible parameters are numerical values, Boolean parameters, text,
character strings and block data. The type of parameter required for the respective command and the
permissible range of values are specified in the command description.
Numerical values
Numerical values can be entered in any form, i.e. with sign, decimal point and
exponent. Values exceeding the resolution of the instrument are rounded up
or down. The mantissa may comprise up to 255 characters, the values must
be in the value range -9.9E37 to 9.9E37. The exponent is introduced by an 'E'
or 'e'. Entry of the exponent alone is not allowed.
Units
In the case of physical quantities, the unit can be entered. Permissible unit
prefixes are G (giga), MA (mega), MOHM and MHZ are also permissible), K
(kilo), M (milli), U (micro) and N (nano). If the unit is missing, the basic unit is
used.
Example:
SOURce:CLOCk 15 kHz = SOURce:CLOCk 15000
Some settings allow relative values to be stated in percent. According to
SCPI, this unit is represented by the
PCT
string.
Example:
SOURce:OUTPut:DIGital:OFFSet:I 0.05FS
SOURce:OUTPut:DIGital:OFFSet:I 5PCT
