04-06-2006 12:03 PM
Hi!
I've generated with the ExpressVI "Simulate Signal" a Square with the maximum frequency of 500Hz (it varies). Now I want to count the falling flanks.
I tried this with the "Trigger Counter.vi"-Example which I slightly changed for my purposes. (see attached file) But it seems as if the Counter is not fast enough for my Signal (- it counts too slow).
Does anybody have an idea how I can solve the problem and count the correct value of squares?
Shorty to my system: I tried it with a 2GHz Sempron with LabView8
and with a 1,3GHz Centrino with LabView7.1
Thank you in advance
Hendrik
04-06-2006 12:20 PM
Puplicate Dost, see here:
http://forums.ni.com/ni/board/message?board.id=40&message.id=3422
04-06-2006 12:36 PM
04-06-2006 12:42 PM
04-06-2006 02:51 PM
If you have a simulated square wave waveform, you can count falling edges by simple emulating what a counter does, essentially for each poind threshold it. If it is above some threshold it is a high value, and if it is below th it is low, use a shift register to compare sequential hi/low booleans. Check for a high to low transition (if n-1 is high and n is low there is a falling edge) use another shift reg to count these events. Do this for every point in the waveform. If you have simulated a noisy signal, you can get more advanced usint techniques such as a schmitt trigger (hysterisis).
Paul
04-07-2006 03:32 AM
04-07-2006 06:26 AM
12-09-2010 01:03 PM
Do you have the trigger counter.vi? I don't have it in my examples.