I am having difficulty understanding how the timing for the Simulate Signal Express vi works. Can anyone help?

[Laura121]

I am generating a signal at 100,000 samples per second. The frequency is 4Hz. I then pass the signal through the basic trigger detection vi to find where the waveform crosses 0.5.

Since the signal is 4Hz, the waveform should cross 0.5 every 0.25sec. However, when I formed an array of the times the trigger is activated, it is not 0.25 seconds.

I am not sure if there is a problem with my calculation of the simulation time, or if I am not understanding how the signal simulation vi works. Thank you for your ideas!

[JÞB · Accepted solution]

Yes, You've made some mistakes or bad assumptions about that express vi.

Frequency is 4Hz Samples per second is 100,000 (Orders of magnatude too high) samples generated are 76 (0.76mSecs worth of data).  1% duty cycle so a transition only occurs once every thousand loops! 1315 or 1316 loops between L-H transitions to be more accurate

Try

40s/sec

40Samples (one sec of data)

50% duty