NI 6211 Choosing external clock source for counter frequency measurement

[odessy27]

Hello Everyone,

    I was wondering, if, for NI6211 there is any way of doing continous counter frequency acquisition, without the use of implicit clock. I am currently using it to measure frequencies ranging from 10Hz to 100kHz. Issue with this is, with implicit clock, the acquisition rate is controlled by the frequency signal, and at lower frequency acquisition is fine but at higher input frequencies the acquisitions is very fast so that I get a buffer overrun error. 

   I was wondering if there is a better way of dealing with this by using some other clock signal from 6211 and make the VI operable at al frequencies.

[John_P1]

It's undocumented/unsupported, but the 6211 should be able to take a frequency measurement using an external sample clock (you could use the other counter or freqout to generate it).  If I recall correctly (again, there's no documentation, and I don't have a 6211 to verify), the most recently acquired frequency sample should be returned.  If there are no frequency samples between clocks you will receive an error.

Best Regards,