How can I end my AI acquision with PFI/DI signal in continuous acquistion mode?

[Yiming_Zhang]

I plan to design the following program: one PFI/DI channel controls the acquisition of 4 AI channels. When the DI/PFI signal changes to high level, the acquisition starts. When the DI/PDI signal changes to low level, the acquisition ends. The acquisition time The time is long and sometimes short. I'm using a trigger VI to control the start of acquisition via the rising edge of the PFI channel. I've looked at many examples where this simply requires setting the trigger VI to start triggering and placing it before the start task VI.

But when I designed the acquisition stop program, I encountered a problem. According to the NI support document, the reference mode of the trigger VI can be used to stop the acquisition.

However, the reference trigger can only be used in Finited samples mode, which conflicted with the continuous acquisition mode I was using.

How can I end my AI acquision with PFI/DI signal in continuous acquistion mode?

[ZYOng]

You can combine reference trigger with retriggerable task.

[Kevin_Price]

It sounds like you have a good use case for a Pause Trigger, set to pause when low.

Then you can set up continuous sampling, knowing that sampling will only *actually* happen while the external digital signal is high.  Which I *think* is what you're looking for.

The catch is that you'll need to scheme up a way to *notice* when the digital signal goes back low in order to know acquisition is complete.  And if the external signal might pop up high again, you need to notice *before* that happens.

-Kevin P