time stamp gap

[BasketSoccerBall]

Hello,

I am using PCI-5154 to measure waveform frequency by edge triggering. when I looked at the time stamp, there are a time gap between data blocks. It is repeated after certain number of data recorded. I am trying to understand if it would be related to fetch-poll function...

C with NIScope driver, 65536 record length per measurement, 1GHz sampling, 64MB onboard memory/ch, 1channel input

0.1-0.2 sec gap approximately every 830 measurements

[cbutcher]

If you take a single measurement and collect the data from the onboard memory after the acquisition finishes, does the same problem occur?

[BasketSoccerBall]

No, single measurement does not show the same problem. 

Please take a look at the attached file. The plot shows velocity vs. arrival time. The velocity is calculated by FFT of measured single waveform which is 65536 samples with 1GHz sampling. The arrival time is the time stamp at the waveform peak. The plots show the dead zone of arrival time between data blocks and it is repeated. I am trying to figure out the source of this dead time. Thank you!