fft of integer signal

[bcglaxer]

When I scroll over the wire, it will tell me that I've connected two terminals of different types: Source is word (16-bit integer) and sink is double (64-bit real). Naturally, I tried to convert the source signal to double, but then suddenly the sink became waveform. It's very curious.

[JÞB]

so a scalar and not an array correct?  the FFT will error without an array input.   very odd polymorhism activity.  I would suspect that a couple of the sub-vis got swapped.  Try unistalling the toolkit and reinstalling it clean from NI media.

[Coq_Rouge]

The FFT function you are trying to use need a waveform as input. Refer to the following VIs for examples of using the Build Waveform (Analog Waveform) function:

Add Waveforms example VI: labview\examples\Waveform\Operations.llb

Create Waveform example VI: labview\examples\Waveform\Operations.llb  

Also doing a FFT with one sample is pointless

I recommend reading this as a starter, before using FFT functions http://zone.ni.com/devzone/cda/tut/p/id/4278

Then you are stuck in Labview go to help in the toolbar, then Find examples. I have used Labview for many years but I still use it 😉

Good luck 🙂