Counter Coupling

[Ashesh]

I have a PCI-6602 counter card which I wish to use for a high precision timing application which involves synchronisation between two counters generating pulse trains at different frequencies.  For this purpose I need to couple 2 counters - i.e.  the output of one counter should be connected to the source of the second one such that the second counter generates a pulse train using the 1st counter's output as its  clock/timebase (and hence the second counter's output frequency is a factor of the 1st counter's). Is there some way of directly coupling the 2 counters on-board, instead of physically (externally) connecting the relevant terminals?

Related to this question, can one route a signal onto an RTSI line using 'route signal.vi', and also read the signal off the same line (though, to a different destination then where it came from), on the SAME card? For example, can I route counter 1's output onto an RTSI line and have it routed to counter 2's source, if counters 1 and 2 are on the same card? Or does one violate all input/output norms when attempting this?

Thanks for any advice I may get,
Ashesh

Message Edited by Ashesh on 07-04-2006 08:00 AM

Message Edited by Ashesh on 07-04-2006 08:00 AM

[Kevin_Price]

Yes, you can definitely route one counter's output up to a RTSI line and then configure another counter to use that same RTSI line as the timebase source.  If the counters are on the same card, you don't even need a RTSI cable inside your PC.  I used this little trick quite a bit with the 6602 under traditional NI-DAQ.  I found it to add helpful flexibility without the need for screwdriver work.

I've switched to DAQmx for new development, and it handles this kind of flexible routing more automatically.  No explicity routing to RTSI is needed.  Perhaps they use the RTSI routing mechanism under the hood, but I don't really know.  If this is a new app, I'd highly recommend DAQmx because traditional NI-DAQ is a bit of a dead-end these days.

-Kevin P.

[Ashesh]

Thanks Kevin. I shall attempt doing this. It is a new application, and we are switching to DAQ-mx soon.
-Ashesh