Rohde & Schwarz R&S FSP Series, Operating Manual

Page: 761 / 796

Operating Manual 1164.4556.12 - 06 7.27
R&S FSP Remote Control – Programming Examples
More Complex Programming Examples
status = viRead(analyzer, result$, 6553600, retCnt)
status = viWrite(analyzer, "TRAC:IQ:STAT OFF", 16, retCnt)
'Stop I/Q data aquisition mode if no further measurements are
'to be done
END SUB
REM ************************************************************************
7.3.10
--- '''''''' ''
Averaging I/Q Data
The R&S FSP has averaging capability also for I/Q measurements, i.e. I/Q data can
be averaged over several test runs. This is subject to the following conditions:
1. An external trigger signal must be available for data measurement, and the trigger
signal must be phase-locked to the signal measured.
2. The same reference-frequency signal must be used for the DUT and the
R&S FSP.
3. The sampling rate must be 32 MHz, since only with this sampling frequency will
the measurement be performed phase-synchronous with the trigger signal.
If all of the above conditions are fulfilled, no phase shift will occur between consecu-
tive test runs. Phase shift may invalidate the measured average so that in extreme
cases a value of 0 is obtained.
The default setting of the instrument for data measurement without averaging has to
be changed as follows:
'--------- R&S FSP default setting ---------------------------------------
CALL SetupInstrument
'Default setting
status = viWrite(analyzer, "TRAC:IQ:STAT ON", 15, retCnt)
'Activate I/Q data acquisition mode;
'this must be done before TRAC:IQ:SET!
'Select max. number of test points (= 128 * 1024 – 512) at
'10 MHz RBW, 32 MHz sampling rate, external trigger, pos.
'trigger edge and 0 s trigger delay.
status = viWrite(analyzer, "TRAC:IQ:SET NORM,10MHz,32MHz,EXT,POS,0,130560",
45, retCnt)
status = viWrite(analyzer, "TRAC:IQ:AVER ON", 15, retCnt)
'Switch on I/Q averaging
status = viWrite(analyzer, "TRAC:IQ:AVER:COUN 10", 20, retCnt)
'Set 10 test runs
'--------- Read data in binary format -------------------------------------
...