How to re-trigger analog acquisition?

[Dennis_Knutson]

Why have you made it so complicated? I know what you are doing and you don't have to explain that. What I don't understand is your reasoning for doing it that way. Is the pulse connected to anything else?

[belopsky]

Well, since I'm still fairly new to programming in general, things that are simple tend to be complicated..

Your guidance is appreciated.

[belopsky]

I am not sure how else I would start acquisition if I need it to start on the falling edge of the counter if not for the trigger?

[LukeASomers]

If you just leave off any triggers, it will start the moment you run the 'Start' vi.

Triggers are for if you want the task to start based on some external signal. Is there an external signal that you need to synchronize off of?

As for stopping, you will just need to gather data repeatedly and based on that accumulation decide when you're done.

[Dennis_Knutson]

You still have not answered the question of why you think you need an external trigger. A front panel Boolean can trigger the acquisition all by itself. One simple easy is to have an event structure with the DAQmx Read inside.

[belopsky]

I thought I needed an external trigger (from CTR0 to PFI0) to tell the acquisition to start

[Dennis_Knutson]

No.

[belopsky]

Let me rephrase - I thought that was a good way to ensure the acquisition starts as soon as the pulse goes low.

[Dennis_Knutson]

You are just talking in circles now. Somehow, you've become fixated on the external trigger. Unless you explain what is important about the external trigger (i.e. for synchronizing to something the counter is also driving), then I'll just assume you are making a beginner's mistake. I've asked you a couple of times what else the counter is connected to.

[belopsky]

🙂

Counter is not connected to anything other than PFI0

Counter is driving the relay, but I thought it was best if I used the trigger to trigger the acquisition.

Alternatively I was thinking of running a physical wire to a digital line and reading the line status. If the line is 0, start acquiring and logging.