gated acquisition of data using a triangle waveform

[MaartenE]

Hi All,

I had a question about the gated acquisition of data. I have two photodiode signals incoming (0-1V) from a usb-6211, as well as a (more or less) triangle waveform (0-10V) Now I want to analyse the photodiode signals, but ONLY when the derivative of the triangle is positive (upward). Whether or not I am measuring the data in between is not really important, as long as I don't use that in the treatment of the data.

Any help would be appreciated!

Regards,

Maarten

[farora]

Hi Marteen,

one possible solution could be the following:

1.) Use the consumer producer model, within the producer loop, you do the complete data acquisition within one thread, within the consumer loop, you do the analysis of the data.

2.) The analysis you could do in fifferent ways. First of all, if your triangle signal is noisy, you can filter it and after that you can make the derivation for analysing, if the data is falling or decreasing. of you cmopate the absolute data. In these ways, you can find out, if the signal is decreasing or falling. There ase also min/max functions, which find the min and max value within a data stream.

3.) Now you have the range of rising values. If the signal is periodic, you can think about doing the analysis only once.

Regards