how to use the gate on PCI-6602

[Yin Lu]

We just newly purchase the counter card PCI-6602. We intended to use the pulse generated by counter 1 connected with counter 0 gate, in order to reset the counts of counter 0 at a certain frequency. However, I could not make the counter gate work properly with the vi examples from labview 7.1. Would you please give me some suggestion in this? Thank you very much.

[NI-Bongo]

Hi Yin Lu,



You'll need to be running a continuous pulse train generation task on the other counter to generate the gate signal for the buffered event counting, as you already mentioned.  An example program that does this can be found in the NI Example Finder under Hardware Input and Output » DAQmx » Generating Digital Pulses » Gen Dig Pulse Train-Continuous.vi.

Here's a document that discusses how to do buffered event counting with NI-DAQmx.

Buffered Event Counting
http://zone.ni.com/devzone/cda/tut/p/id/5404

An example program that does this can be found in the NI Example Finder under Hardware Input and Output » DAQmx » Counter Measurements » Count Digital Events » Count Digital Events-Buffered-Continuous-Ext Clk.vi.  For the sample clock source, you will want to use CtrXInternalOutput, where X is the counter you use for the pulse train generation.  If you are not able to see this terminal on the drop-down menu, you may have to right-click on the Sample Clock Source control and select I/O Name Filtering...  When the Filter Names pop-up appears, make sure to check Include Advanced Terminals.  Then the CtrXInternalOutput should be available.

The gate signal will latch values into the buffer, so if you want the number of edges between each gate signal, simply process your output array by subtracting the previous element from each element of the array.

I hope this helps to get you started.  Let me know if you have further questions or if you have more specific errors or problems you would like to discuss.

Getting Started with NI-DAQmx
http://zone.ni.com/devzone/cda/tut/p/id/5434