Changing the number of samples obtained

[vaishsuri]

Hello!!
I am new to using RED Pitaya and also to Signal Processing in that case. My task with Red Pitaya is to acquire the signals from a Phase Doppler Anemometry system and then compute the frequency and the phase difference for calculating the velocity and diameter of a droplet generated.
Now I am just using signals from the function generator to see if my code is properly working.
I used the help of this code http://redpitaya.readthedocs.io/en/late ... -exm1.html to acquire the signals and I am done processing the signals and getting frequency and phase difference. But I am getting 16384 samples. But I want only 256 or at the maximum 512 samples. I tried changing the decimation factor. But, it doesn't seem to be working out for me. So, could anyone guide me if there is a way to reduce the number of samples may be based on some threshold value (Like to capture signals burst by burst). Thanks in Advance.

Vaish

[JohnnyMalaria]

The SCPI ACQ:SOUR group of commands let you specify how many samples to read. Refer to http://www.alldaq.com/fileadmin/user_up ... elease.pdf This document cross-references the equivalent C API routines. Some of the information in the document is out-of-date and incorrect, though.

I had to do something similar (for measuring phase from a laser Doppler velocimeter as it happens) and wrote my own code to read data in "chunks". Search for other posts by me to see the source code.