error 200077 occured at Property Node DAQmx Trigger in DAQmx Start Trigger (Analog Edge.vi:1->CRT with Trigger

[mmmhmmm]

I have created a program that will read analog data and chart a waveform but I need to stop the program when the voltage declines to a certain voltage. When I tried the analog edge trigger it showed the error in the subject:

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

Property: Start Trig type

Requested Value: Analog Edge

You Can Select: Digital Edge, None

I understand from this that the analog trigger is not available for my DAQmx version, without getting new equiptment, can I use a trigger to stop reading data at a specific voltage?

How does the digital trigger start and stop an analog read?

Thanks in Advance!

[mmmhmmm]

Here is the program

[chipsahoying]

Hello mmmhmmm,

What if we were to look at the output of the DAQmx read and compare it to the shut-off voltage and use that boolean to shut the loop off?

This is a brute-force method - it can be slow if there are a lot channels involved, as it uses a for-loop to check all of the channels, but it might work for your application.  If you have only a single channel of data of output, you can change the output of the Read DAQmx to a 1-channel (and remove the for-loop).

You should be able to drag and drop the png attached into your while-loop - the waveform going to your DAQmx read output, re-wire the stop button to the or array output (and replace the stop control with your own).

Let me know if you have any further issues.

[mmmhmmm]

This project was put on a back burner for a couple of weeks but I believe I set it up as you described but when I plugged in my value and ran the program, it did not stop reading the data when it reached my trigger value and the boolean did not switch until I manually stopped the program. Am i wiring the stop button wrong?

[chipsahoying · Accepted solution]

Ah! Okay, so the Status boolean would be hooked up to the status from the unbundled error wire, the stop boolean to the stop button, and the the boolean to the right would be for the stop loop itself...so something like this (see attached image).  This is a snippet from LabVIEW 2014, so it may not easily drop into your version, but hopefully it's clear enough on how you can wire this up.

[mmmhmmm]

That worked beautifully! Thank you!