valid waveform determination

[Pablop]

My program aquires a few channels of TTL signals and then analyses them. If one of the channels is dead, the aquisistion looks like noise. Unfortunately, I've got some programming that can get stuck in a loop as it uses the data to make some calcualtions.

Is there VI that can be used as quick check that the data is valid versus noise?

[Russ_Evans]

Hi Pablop,

I think the only way is for you to determine a set of criteria for what is "valid" data. What difference are there between your valid data and your noise? I would look at amplitude and frequency off the top of my head. Does the noise have values or a range of values that are not present in the valid waveforms. How about frequency? Is the noise at a higher frequency say than you real signals. Would spectral analysis show peaks at frequencies not present in your valid signal? Labview has many analysis vi's like filters, FFT etc that would aid in your determination.

Cheers,

--Russ