"Sinusoidal Noise" coming out of LabVIEW

[ald43]

Hello,

I am new to LabVIEW and I am just doing a simple case where I am just trying to measure the output from my NI-USB-4431 but I am getting this weird "Noise" (I am not sure what to call it) that is always being sent out from the DAQ, every time exactly the same.

If someone knows what is possibly creating this weird sinusoidal pattern in my output that would be appreciated.

Thank you

[RavensFan · Accepted solution]

That doesn't really look like noise to me.  At least not in a typical random, spiky way.  At first I would have thought maybe you were picking up some 60 Hz noise from some electrical source.  But that seems to be a pretty clean higher frequency sine wave laying on top of your sine wave.

By counting the smaller peaks, it looks to be about 20 Hz.  Would that value mean anything to you?

[aputman]

Are you using a simulated device?  Check in MAX.  If the device shows up as a yellow icon, it's simulated.

[RavensFan]

I think a simulated device only puts out a single frequency sine wave.