Pulse Generation application with DAQmx and a PXI-6624 module?

[scooby]

What is the best implementation method for the following pulse generation application

using LabVIEW, DAQmx and a PXI-6624 counter\timer module?

I have two rising edge trigger signals (Trigger-1 and Trigger-2).

There is ample spacing between each trigger. They never occur at the same time.

I need to generate a single pulse (fixed width, variable delay) whenever Trigger-1 occurs and

a finite pulse train (fixed width, variable delay, N-pulses) whenever Trigger-2 occurs.

However, the output must appear on one counter output because this composite signal

will be used as a trigger source for another PXI module in the rack.

With DAQmx and a TIO counter\timer can I use both the GATE (for Trigger-1) and

AUX (for Trigger-2) at the same time on the same counter to gate out the desired pulses?

Trigger-1 would be wired to the GATE of CTR0. One Trigger-1 event would generate one pulse on the output of CTR0.

Trigger-2 would be wired to the GATE of CTR1 and the output of CTR1 would be routed to the AUX input of CTR0.

One Trigger-2 event at the GATE of CTR1 would generate multiple pulses on output of CTR0.

Would DAQmx and the PXI-6624 TIO support this implementation?

What is the best way to accomplish the task at hand.

Thank You.

Best Regards,

Scooby

[Laura F.]

Hi Scooby,

I have looked into the application you have described and I see a potential problem with what you describe.  In DAQmx, it is not possible to call the counters of the same DAQ device in the same task, so you cannot have the finite pulse train generation and the single pulse generation tasks running at the same time.  What you can do, since you mention the triggers will not occur at the same time, is to stop one counter task while you are triggering another.  The way I would suggest you merge the outputs is with a two input Or logic gate to avoid damaging your counters.  Your signals will effectively be added together by this logic gate.   I do not see any way to merge the outputs internal to the DAQ device. 

Please let me know if I can be of additional assistance.

Laura

[scooby]

Hi Laura,

Thanks for the reply.

This application started out very simple ...

Generate an ARB waveform output with variable delay in response to each trigger.

The PXI-6624 could handle the high voltage triggers I have to process.

Your OR-gate approach is the right way to go.

I will probably have to replace the PXI-6624 with a PXI-7811R RIO board and

condition the triggers externally.

Thanks again!

Best Regards,

Scooby