TestStand slow execution

[sowshankar3007]

Hello All,

I'm reading analog signal with DAQmx card(NI 6368). My signal period would be more than 10 seconds sometimes.

So I made N number of reads with loop. Eg, samples per read = 100000, Sample rate = 200000. But I want to capture 2s(period) of a signal. So I made DAQmx read for 4 times.

My problem is, after executing 1st DAQ read step in Teststand, It starts executing the steps very slowly.

I'm using GPIB DAQ.

Anyone help me to know what causing the extremely slow execution.

Regards,

Sowbarniga

[santo_13]

Please share the source code to analyze why there is a Slowdown. There are a lot of reasons for the slowdown, typically it could be the actual execution time is slow or there is some kind of memory build-up or inefficient implementation of data processing.

BTW, you mentioned a 6368 (PXIe or PCIe) card whereas, in the end, you mentioned a GPIB DAQ - these are contradicting.

[sowshankar3007]

Hi,

Thanks for your reply. Sorry for the contradictory statement. I'm using PXIe 6368 DAQmx card.

Sorry, I'm not supposed to share the code. But the problem is, for the same test flow it is executing fast for some times and executing slow for many time. I don't understand what is happening at the backend.

Problem starts after DAQ read step.

Best Regards,

Sowbarniga 

[santo_13]

Without seeing the code, we could only guess what is happening.

Always, my first guess will be an incorrect usage of DAQmx functions for high-speed data collection. Unless we could ensure you've implemented the code correctly it does not make sense to suspect any issue on the DAQmx side.

If actual code cannot be shared, please recreate a small example to see if the problem occurs there too.