There are a few solutions to get the frequency of your signal in LabVIEW. The simplest solution is to use the 'Extract Single Tone Information.vi' This VI takes a signal in, finds the single tone with the highest amplitude or searches a specified frequency range, and returns the single tone frequency, amplitude, and phase.
You could also use the power spectrum.vi to find the frequency components of your signal as well. You could then perform a peak detection of the output to get the strongest component.
Kevin R
Applications Engineer
National Instruments