Get frequency value from Power Spectrum

[livermor]

I am rather new to LabView, and want to measure the frequency of the peak in a power spectrum from a real signal. Further, I want this frequency value and its amplitude to be recorded in a file. Right now I am able to plot a power spectrum using an express VI, which gives me the correct frequency value in the graph. 

However, I am not able to extract the value of the frequency using different VIs I've found in LabView after browsing through the various discussions in this forum. Can someone please point me in the right direction? I am using a NI PXI-5124 Digitizer to record the signal in a NI rack.

[IanW · Accepted solution]

If it's the dominant frequency you're looking for you can use the Extract Single Tone vi. You can also modify this vi to include search details if it's not the dominant frequency, I've not included this in my example but you can check it out in the help file.

Ian