Is my counter card affected by computer operations

[wheeler]

I have a 6602 counter card and two encoders. I will eventually have 5 encoders, so as of right now, I have 5 sperate VI's that run simultaneously, echa with its on configured channel and set-up. My encoders have an assumed constant speed of rotation, and my Vi will give me the encoder pulse difference each second.
When encoder channel 0 is turned on, everything is good and the "encoder pulse diference" is relativley constant. then when i turn on channel 1, the count is constant, for about 4 or 5 secondsm and then the count difference goes into a pattern, mid(100), high(190), mid(100), mid(100)low(50), mid, mid, high, mid, mid, low, mid, mid, high, mid, mid, low, ....after some time, it will just stay mid, then go
back into the patter, then stay mid again. sometimes, I can make the mid, high, low pattern stop by opening another process(word, excell, internet, etc).
I have even written a seperate VI tht will read all 5 channels at the same time and i get the same pattern.

[Filipe A.]

Hello;

Instead of having 5 independent VIs running in parallel, I believe that having only one VI with the 5 operations together would improve the overall results.
I'm attaching a VI that shows how to configure more than three counters of the 660x board to execute at the same time. You will just need to change the VI to meet your applications needs.

Hope this helps.
Filipe A.
Applications Engineer
National Instruments