I want to do FFT analysis on data gathered with Daqmx hardware - a cDAQ NI 9174 with a NI 9232 Sound and Vibration module. The goal being to find a resonant frequency and graph of the frequency domain data using Diadem. I gathered the data using the sample program IEPE - Continuous Input in LabVIEW and saved it as a TDMS file.
When I go to do the FFT analysis, I select the accelerometer data for the given access and leave all the default options. Is this the correct procedure? Do I need a Time signal, and if so, how do I generate one for any given TDMS data? Data saved in TDMS format should be of 'waveform' type, so I was thinking it shouldn't require it. However, the FFT generated does not match the analysis done by our vibration software running in parallel, and I'm trying to find the source of error.