AnsweredAssumed Answered

speed up data transfer in zero span mode

Question asked by joanna on Feb 9, 2016
Latest reply on Feb 9, 2016 by wstark

i'm doing some  measurements where I'm using port 1 to output a CW signal, and then measuring changes in power at the output signal frequency in zero span mode. I'm triggering at 20 Hz.

My signals are fairly small, so I have to average about 100-400 time traces. 
I can't seem to do this onboard (I know there is an averaging option in SA mode, but it doesn't seem to work in zero span mode). I want my resolution bandwidth to be as large as possible so that I can get the best temporal resolution/shortest risetime. 

I'm using SCPI in matlab to read out my traces, which I have set to have 6001 points:

fprintf(FF, 'FORM ASC,0; *OPC');        %I'm pretty sure this is the default 
fprintf(FF, 'SENS:BAND:RES MAX');  %i need to 5 MHz bandwidth
fprintf(FF, 'DISP:ENAB 0')                  %speed things up a little by not updating display

data=query(FF, 'TRAC1:DATA?');        %read each sweep. this is the prohibitive step

I've had a look, and it seems that the fieldfox has automatically turned the battery saver off, so I'm pretty sure that any time associated with turning the battery saver on/off between traces is overcome. 

My problem is that to obtain and transfer 400 averages, it takes about 40 minutes, even though each trace only has 6001 points. Is there anything that I can do to speed this process up? will formating the data as a REAL64 help? is there a way of storing all the traces on the fieldfox and then transferring them in one big block a better option? 

Would it help if I could find a way of having a constant (not triggered) cw source, and only triggering the time measurements? 

Thanks for your help

p.s. I've included my matlab code with the commands iIve used pasted into one file in the order that I call them.


Edited by: Joanna on Feb 9, 2016 8:13 PM