Measurement of frequency of acquired data using NI 9250 and cRIO-9043

[dmtd]

Hello,

 I am trying to measure the frequency of an acquired sinusoidal signal using NI 9250 & cRIO 9043 combination. For that I have used "tone measurements vi" & "spectral measurement vi"  but none of them is showing the actual frequency of the applied signal. I have applied the signal from  a signal generator to the BNC analog input port of the NI 9250 module. I have used  the example program " getting started with NI 9250 ".

Please suggest a possible solution.

Thanks.

  

[Henrik_Volkers · Accepted solution]

how should the DFT or the tone detection vi measure the correct frequency, if you don't feed them with the samplerate(dt) ?

try to avoid the 'dynamic' datatype and the express vis... much better to debug 😉

providing the vi with some sample data also help others to help you 😉

edit: read the property of the DAQ to get the actual samplerate!  The driver will coerce the requested SR to the next higher possible one the actual DAQ hardware supports. If you havn't RTFM and spec of your DAQ, it's a common pittfall to request a not supported samplerate 😉

[dmtd]

Henrik,

Thanks for the guidance. I am getting the right result now.

Thanks again,

DMTD