Sample Clocked Buffered Frequency Measurement

[Gollum]

I have a circuit board clock which I want to test.  The clock should output at ~12 MHz.  I'm using a USB-6343 and would like to use the Sample Clocked Buffered Frequency Measurement mentioned in the X series manual but am unclear on how to set it up.  I believe I need an external clock but am not sure if I can use this card to generate this clock and what rate I should use; but more generally I'm looking for an example on how to set up this measurement in LabVIEW using DAQmx.

In the end I'd like to get an accurate average measurement of the clock frequency over ~1 second if possible and am willing to use whatever method would best work with the 6343 card.

Thanks in advance

[Aix-La-Chapelle]

Hi Gollum,

There's a few examples that you could take a look at that come packaged with LabVIEW. If you open the NI Example Finder  (Help » Find Examples), then in the Browse tab click the following: Hardware Input and Output » DAQmx » Counter Input.  In there we have a few examples on how to read in the frequency using DAQmx calls.  The property that is mentioned in the Sample Clocked Buffered Frequency Measurement (CI.Freq.EnableAveraging) can be located using the following method:

In LabVIEW go to View » Class Browser, when the Class Browser window open, for Object Library choose DAQmx and for Class choose DAQmx Channel.  In Properties & Methods expand the following: Properties » Counter Input » Frequency » Measurement Specifications » Enable Averaging.  The Class Browser can be used to find several property nodes, and is very useful.  You can play around and find various properties that can be changed in there.

Hopefully this helps.  

[John_P1]

Additionally, you do not need to use an external clock for this to work--one can be generated using one of the other counters on the 6343 (and can be routed internally if desired).  If you need help with this don't hesitate to post back.

Best Regards,