Gated counting by both rising and falling edges with PCI 6229

[hanyu]

Hello experts, I have a pulsed signal and a square wave gating, and I want to count the difference of pulse numbers between high gate and low gate in a single period (1kHz). What's the best way to realize this in labview? Thanks! I already had a little vi to count via only the rising or falling active edge.

[Dsun]

One method that is native to LabVIEW is change detection.  Since you have an M series PCI card, you will be able to access this feature.  It essentially detects changes on a digital signal when it switches between high and low.  Here's an article about it.

http://www.ni.com/tutorial/4102/en/

[hanyu]

Thanks Dsun! That works!