why I cannot use counter 0 and counter 1 simulatously

[shireman]

I am using a 6602 broad to perform 2 channels countering. The mode of two counters(counter 0 and counter 1) are both "buffered period counting". The source signal of both counters are internal timebase. And I want to count the gate signal in the source's period. When I use them solely, they runs well. But when I use them synchronously, I found the results of both counters is wrong. Even when I use counter0, the result is wrong when there is a input in the gate of counter1. So what is the possible reason? How can I do?

[Kevin_Price]

Could it be that you aren't specifying unique group numbers for the two counters?

See: http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/c39a19c690e79007862567ba0055c7a1?OpenDocument

[shireman]

Thanks, Mr Price

But I haven't made that mistake. I have specified the group znumber. But it didn't work. When I connectted only one signal to the gate of counter 0, it works well. But when I connectted the both signal to the gates of counter0 and counter1, the reslut of counter0 is wrong. But the problem is there is no vis about counter1 in my programme!! I think may it is my connecttion mistake make all thing wrong. I only connect gate of counter0 and counter1 to the signal. and the sources of both counter remain, which I set the source as the Internal Timebase. I also connectted a trigger signal to the gate of counter2(PFI_31).

So what is the problem can it be? How can I do?

[Kevin_Price]

I'm not sure I have a clear enough picture. Hopefully I can help more if you can:
A. Post some example code - please make sure that the actual config settings you use are set as default values.
B. Describe the intent of your measurement. For example - you introduced some info about a trigger signal for a third counter, but I don't know how you intend that to relate to the first two counters where you see the problem.
C. Describe the nature of the error/problem. How is counter0 wrong when the signal is connected to both? Does the same kind of problem occur when operating counter1 alone? What exactly happens when trying to operate both at once?
D. Describe the physical wiring of signals into the connector block.