Analog trigger for NIDAQ Tools Pulse Train Generator

I am trying to get analog triggering to work using the NIDAQmxPulseTrainGenerator that came with NIDAQ Tools. I have a PCIe-6363 and BNC2090A. When I try to use an analog trigger with the source being "\dev1\APFI0" and type "analog level", I get the following:


 NI-DAQmx driver error while calling function DAQmxCfgAnlgEdgeStartTrig;

 device Dev1:-200077: Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.

Extended info:

Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.

Property: DAQmx_StartTrig_Type

Requested Value: DAQmx_Val_AnlgEdge

Possible Values: DAQmx_Val_None, DAQmx_Val_DigEdge

Task Name: Dev1_CTR_0

Status Code: -200077


Unless I have misread the specs, I am almost certain that this card supports analog triggering. I have tried different strings for the source ("APFI0","dev1\APFI0","APFI1", etc.), but still get this same error. Is there something I am missing? Any help would be appreciated. Thanks!

I think the analog trigger is only available for analog input scanning (I suppose because it depends on the ADC). I think the part of the error message that says, "The property value may be invalid because it conflicts with another property" is a red herring. If you can set up an input scan, then you can attach your counter trigger to /Dev1/ai/StartTrigger.

I don't think I understand. Is there no way to trigger a pulse train off of an analog signal?  For the DAQmx_CTR_OutputPulse, there is a /TRIG flag where it seems that analog trigger is an option. Am I misunderstanding how this function works? Thanks again for your help.

The analog trigger depends on hardware support. The error message you got indicates that your hardware doesn't support an analog trigger for the purpose.

My earlier suggestion was a work-around for using the analog trigger available for scanning in order to trigger your pulse train.

Perhaps you should tell us what your goal is- perhaps there is a different way to solve the bigger problem. It is easy to fall into the trap of asking questions about implementing a particular approach to solving your problem, when it may be that what you need is a different approach.

I am recording a quasi-periodic signal with the FIFO procedures. Whenever it reaches a certain level, I want to trigger a short pulse train with a certain latency.

Your solution, if I understand correctly, is to split off this signal and use it as a trigger for a separate input scan. The start of this scan can then be used as a trigger in the pulse train generator panel. I will give it a try.

Just out of curiosity, what is the property of the ADC that would allow analog triggering for the pulse train generator? I ended up buying a specific card (PCIe-6363) because the specs said it had analog triggering, but is there an additional feature I should have been looking for?

Thanks again for all your help!


If you are already using the analog inputs, you can't set up a separate analog input task for this purpose.

I've done a bit of reading in the PCIe-X series user manual- it seems that analog input, analog output and digital I/O can all use analog triggers. If you aren't using one of those systems, you could set up a task with analog trigger just so that you can route the start trigger signal to the counter's trigger input.

I am not really an NI hardware expert, though I know quite a bit about it because I wrote NIDAQ Tools MX. I am not aware of a device that has the capability you want.

You can also sign up for the NI forums- you might get better answers there. But be prepared to get answers with Labview connection diagrams!