How to analyze two separate parts of a signal

[Nicreap]

This is what my data looks like.  Its hard to tell but on the bottom part there are peaks.  I want to be able to detect those peaks and find the amplitude when the signal is at the low part, and when it is at the high part run another analysis.  Is there a way to get labview to recognize the two different parts separately?  Or do I have to tell it to perform the analysis for everything and just deal with unnecessary overlap?

[vt92]

Take a look at the waveform palette.  There are tools there to find transitions, make measurements etc.  I would start with the transition measurement to find the points at which your signal switches high/low and low/high.  Then, you can separate the waveform into chunks that can be correctly analyzed.

[H_SH]

Hi,

You can break your signal based on your limit/trigger criteria for lower part and higher part. If your limit is variable you may need to design algorithm for it and break your signal.

- HS

[johnsold]

Create a data subset for original points less than 2. Then subtract the mean value of the subset. What is left should be your variations, centered around zero.  Look for your peaks/valleys there.

Is your data digitized with sufficient resolution to see what you are looking for?  If you expand the scale on the graph you posted so that the Y-axis shows something like 1.3000 to 1.3001, do you see the bottom peaks?  If not, your resolution may be inadequate and the data may not be there.

Lynn

[Nicreap]

Yes, the resolution is high enough, it's just the peaks end up being so narrow, its hard to see when overlayed.  Thanks for your help.  

[Nicreap]

Yes, the resolution is high enough, it's just the peaks end up being so narrow, its hard to see when overlayed.  Thanks for your help.