Hi, I'm using a BNC 2121 to do event counting.
I used the example for counting provided by NI. The only difference is that I plot the difference between current count and previous count as the loop updates.
By varying the loop update speed (the wait for next millisecond multiple) I vary the noise and this will also depend on the source I am counting which is fine.
My problem is that as the millisecond multiple goes small (2ms) I start to get periodic spikes which are much larger than the noise. If I go to 1ms the average completely moves to the top of the spikes which were at 2ms.
Does anyone know why this would happen? Is there some kind of limit in either labview or the BNC 2121 to how often a counter value can be updated?
This might be difficult to grasp or I am not making it clear I'll probably post some pics later.
