Find the first peak

[labjansen]

Hi

I am new to LabView. I have trouble finding the peak of the signal - see image.bmp. I have lots of data set where I need to find the start peak of the signal. Sample data is in the testdata1.txt file. I need to automate the process and it is not possible to use the peak detection vi. How do i solved this?

Best regards

Christian

[GerdW]

Hi Christian,

there are several approaches possible:

• use the derivative to detect peaks
• use the first x samples to determine a "baseline", then search for samples with value greater than baseline+limit…

Btw. PNG offers much smaller filesize than BMP:

[cstorey · Accepted solution]

You could try this peak detection VI.  It doesn't use NI peak detection.vi.  It relies on a peak being deltaY greater than the surrounding data.  For your data a deltaY of 3-5 looks good.  Then just take the first peak from the array of peaks returned.

Craig