Is there a lower frequency limit to events in buffered event counting using a PCIe-6259?

[KKRand]

I am using a PCIe-6259 to count events using buffered event counting (using C/C++).

I set up to count finite samples with a call to DAQmxCfgSampClkTiming() and specify the gate frequency for rate.

As long as the frequency of events is high relative to my gate frequency (e.g., 10s or 100s of events per gate), everything works fine, but if my event frequency drops below my gate frequency, I get a counter overflow error (-200141). And the gate frequencies we're talking about are rather modest, typically 1-10 kHz.

I do not see this problem on a dedicated counter card like the PCIe-6612.

Thanks for any help!

  Karl

[Kevin_Price · Accepted solution]

Hmm, I'm surprised you're getting *that* specific error.  I'd have expected something related to duplicate count prevention.

You probably have to turn it ON in order to buffer up values of 0 during intervals where you get consecutive gate edges (sample clocks) with no source edges.  It continues to seem like odd terminology that you get *more* measured values when you *prevent* duplicates.

Here's another link to an NI-written explanation, plenty of other forum discussions touch on it as well.

-Kevin P

[KKRand]

Thanks, Kevin!

Indeed turning on the duplicate count prevention did the trick!

  Karl