How to tell if the signal wave exist.

[alex.]

The DAQ will collect multi channel signal together.

Need to detect one of the channel have waveform exist or not.

As the attached screenshot, this channel may has 2 types of signal. The signal amplitude vary a lot, but the profile is almost the same.

But sometime there may be transient noise, or base noise.

May I know how to tell if the signal exist, or just noise exist, thanks.

[ABCPrograms]

Hi Alex,

can you run an FFT or any other analyser on that?

[alex.]

Any other analyzer?

[ABCPrograms]

nope, by running the FFT you can exactly find out which kind of frequences are in it.  

[Cory_K]

What do you expect (theoretically) the waves to look like?
From your drawing, it looks like there is either a "square" waveform or a "sawtooth" waveform.