I am trying to use the PXI-6289 to monitor a number of digital signals. I am using the digital I/O pins for this. I am trying to use the DAQmx to read these with the 10 MHz onboard reference clock. I am reading 2,000 samples at a time, so I would expect the loop to execute every 200 microseconds (us). When I run the attached code and use a tick count microsecond timer I see that the actual loop time varies between 166-247 us. Only 34% of the loops execute in exactly 200 us. I was expecting the sample clock to do a better job controlling for sample timing and computational jitter. Any suggestions? I considered replacing the while loop with a timed loop. If I do that do I still need to use the 10 MHz sample clock?
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