From this post, there are details on several different ways to detect that a DAQmx trigger event has occured, the one of interest being described as follows:
"Our E and M Series devices don't have any
built-in functionality specifically designed for telling you when a
task starts. But there are several options. (Actually, the E and M Series boards do have
functionality built in that can be used to notify an application when a
task starts. It's just that DAQmx exposes these in an indirect way)
1. You can poll the Total Samples Acquired (probably not the exact
name) for input or Generated for output. When it starts to increment,
the task has started."
Other than using a DAQmx read and checking for a timeout, I can't figure out how to do this, or where a property node for this is (for the total number of samples acquired). In my case, I don't want to use the DAQmx read because then when the trigger event has occured I will have read some of the samples already in a part of my program not designed to handle the samples.
I think I will be able to implement one of the other solutions listed in the above post but it doesn't seem as elegant or easy, and solution #1 did not seem adequately explained enough for me to actually try.