Hi everyone,
I am using a PCI 6122 (S Series, DAQ-STC) and Labview 7.1 on a Windows XP. There are only two counters on this card (Ctr 0 and Ctr 1) and I need to use both of them to count edges. While testing the counters, I am inputing a TTL signal of 10kHz to the Gate of each counter, to be used as an external sample clock, and a 20Hz TTL signal into the Source of each counter, to be used as the input signal. Ctr 0 counts 40 edges per second, i.e. twice as many as it should, while Ctr 1 is reading the correct number of edges, i.e. 20 edges per second.
The strange thing is that when I switch the connections of Gate and Source for both counters to measure the frequency (or period), both counters read the correct frequency, i.e. 20Hz. To the best of my knowledge, both counters were reading the
correct number of edges a couple of weeks ago. Also, I have reset the
device several times but it does not make a difference. I am trying to figure out why this is happening and how to fix it, but I am no closer to answering either question. Does anyone have any suggestions?
Thanks.
