Internal Channels in cDAQ-9172

[angelmcdoggie]

 Hello All,

I have limited module in my cDAQ-9172, NI 9125 & NI 9263.

Hence, I cannot fully try the various trigger type examples in VC++.

I tried using the internal channels based from the attachment as trigger source but

unsuccessful.

Can I use these internal channels as trigger source?  How?

Thanks a bunch,

A

[Wayne.C]

Read the section on counters. http://digital.ni.com/manuals.nsf/websearch/D0435486A31A3B038625743900690AEE  It explains what kind of module has to be installed where to access the counters.

Message Edited by Support on 09-03-2008 09:58 AM

[MarkGrot]

Centerbolt is correct if you want to use external signals.  However if you are trying to generate an internal clock or trigger, you can do this without a digital module in slot 5 or 6 of a cDAQ-9172.  You will not be able to use analog triggering (this functionality exists on the modules that support it, such as the 9205 and 9206).

First you'll need to configure your counter task to generate whatever pulse train (or whatever) you are looking for.  To use the internal chassis counters, set the channel to cDAQ1/_ctr0 or cDAQ1/_ctr1 (replace cDAQ1 with your chassis name).  Run that.  Set the source of your trigger or clock to cDAQ1/Ctr0InternalOutput.  That's all there is to it.  That should work.

[angelmcdoggie]

Hello MG,

I tried these 3 examples (no modification) wherein I used cDAQ1/_ctr0 as channel & cDAQ1/Ctr0InternalOutput as trigger source:

  >> GenDigPulseTrainContinuous_DigStart - ran without any compiler or exception errors

  >> GenDigPulseTrainContinuous_PauseTrigger - ran without any compiler or exception errors

  >> ContAcqSmps_IntClk_PauseTrigger  (cDAQ1/Mod1/ai0 & cDAQ1/Ctr0InternalOutput) - ran without any compiler or exception errors.  No display in the NI graph.

I think it all worked but I'm not sure if it did.  How do I check it?

super Thanks!!! 😃

[angelmcdoggie]

Btw, for the counter programs (items 1 & 2), I tried adding a counter reader (based from CountDigEvents program) to see if the program works but unsuccessful. 

After execution, the error referred to the reader was looking for the task to be read. 

Thanks a bunch!!! 😃

[Brooks_C]

Hello AngelMcDoggie,

If these programs run correctly then that means you're generating the pulse train you specify on the counter internal output.  If you want to test that these pulses are being configured correctly then you'll need to make another task to use this pulse train as a trigger/clock source.  For instance you could make an analog input task and set the sample clock source to ctr0InternalOutput.  If you run both tasks then you should be able to see that the pulses are in fact being generated since you'll be taking analog input samples on each rising edge of you pulse train.

Cheers,