Rohde & Schwarz R&S FSP Series, Operating Manual

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Operating Manual 1164.4556.12 - 06 6.243
R&S FSP Remote Control – Description of Commands
TRACe Subsystem
TRACe<1|2>:IQ:DATA?
This command starts a measurement with the settings defined via
TRACe:IQ:SET
and returns the list
of measurement results immediately after they are corrected in terms of frequency response. The
number of measurement results depends on the settings defined with
TRACe:IQ:SET
, the output
format depends on the settings of the
FORMat
– subsystem.
Parameter: none
Example:
"TRAC:IQ:STAT ON"
'Enables acquisition of I/Q data
"TRAC:IQ:SET NORM,10MHz,32MHz,EXT,POS,0,4096"
'Measurement configuration:
'Filter type: Normal
'RBW: 10 MHz
'Sample Rate: 32 MHz
'Trigger Source: External
'Trigger Slope: Positive
'Pretrigger Samples: 0
'# of Samples: 4096
"FORMat REAL,32"
'Selects format of response data
"TRAC:IQ:DATA?"
'Starts measurement and reads results
Return value: The result values are scaled linear in unit Volt and correspond to the voltage at the
RF input of the instrument.
ASCII Format (FORMat ASCII):
In this case the command returns a comma separated list of the measured voltage values in floating
point format (Comma Separated Values = CSV). The number of values returned is 2 * number of
samples, the first half being the I-values, the second half the Q-values.
Binary Format (FORMat REAL,32):
In this case, the command returns binary data (Definite Length Block Data according to IEEE 488.2),
with the lists of I- and Q-data being arranged one after the other in 32 Bit IEEE 754 floating point data.
The scheme of the response string is as follows:
#41024<I-value1><I-value2>...<I-value128><Q-value1><Q-value2>...<Q-value128>
with
– #4: digits of the subsequent number of data bytes (4 in the example)
– 1024: number of subsequent data bytes ( # of DataBytes , 1024 in the example)
– <I-value x>: 4-Byte-Floating Point I-value (max. 128k resp. 512k with option R&S FSP-B70
– <Q-value y>: 4-Byte-Floating Point Q-value (max. 128k resp. 512k with option R&S FSP-B70
The number of I- and Q-data can be calculated as follows:
The command requires that all response data are read out completely before the
instrument accepts further commands.