NI Scope 5122 Variable Sampling Rate

[Steve_G]

Hello,

I'm using an NI 5122 high-speed digitizer card to acquire data and would like to synchronize the sampling rate of the card to the frequency of the data.  For example, my first set of data will have a frequency of 13.6MHz so I'd like to sample at 13.6MHz.  When I connect a 13.6MHz signal to the CLK IN on the front panel of the card and write Labview code to sample at this rate (by either the sample clock or reference clock) I receive error messags.  Does anyone know if its possible to have a truly variable sample rate for this card?

Thanks,

Steve

[Hillman]

Hi Steve,

Thanks for the post and I hope your well today!

I noticed you've not had any support thus far.

Im not very familar with NI-scope, but with DAQmx once the task has commited you wouldn't be able to alter the sample rate. Now with pulse train generation you can (create) what effectively appears to be a didn't sample rate.

So unless NI-scope has built in this functionality, Im not sure it would be possible. 

Could you maybe attach your code and the error details?

Kind Regards,

[dansch · Accepted solution]

Hi Steve,

I understand you are using a 5122 high-speed digitizer and trying to use an external sample clock. What type of error messages are you receiving when doing this? Additionally, how are you configuring the device to use this external clock?

I would also like to point out that there is a very useful example program in the LabVIEW Example Finder (Help » Find Examples) that can be found under Hardware I/O » Modular Instruments » NI-SCOPE » Features » "niScope EX External Clocking.vi" which allows the user to perform a simple acquisition using an external clock source. To specify the external clock source, rate, and divisor, an niScope property node is used. You should be able to try out this example and use the same method in your program. Hope this helps,

[Steve_G]

Daniel,

Thanks for the info about the example vi - it worked great.

Steve