Your impulse event is putting another element in the queue which has not state bundled into it. So it is getting the default enum of Start.
When the Start case runs, you are actually breaking your acquisition because you don't have your DAQmx task wired through that case. You can also see there is a Use Default if Unwired tunnel on the right hand side of your shift register. So when Acquire runs again when that element comes through, it can't acquire because now you have an empty DAQ task coming out of the purple shift register.
You could wind up loading more queue elements then you meant over time.
If you hit the Start button, Initialize then Acquire queues up.
Initialize runs, acquire left in queue.
Acquire runs, it reenqueues itself. Does this repeatedly. Good.
Impluse button is hit, Now acquire and "Start", the default enum are in the queue.
Acquire runs, it reenqueues itself, now Start and Acquire are in the queue.
Start runs. It breaks the DAQ task wire, Now Acquire is in the queue.
Acquire runs, it re-enqueue itself. Does this repeatedly, but with the broken task wire, nothing works.
If you hit the Start button again, Initialize and Acquire queues up. Now you have Acquire, Init, and another Acquire in the Queue.
Acquire runs, re-enqueues, now you have Init, Acquire, Acquire.
Init runs, it finally fixes the broken DAQ task, now you have Acquire, Acquire.
Acquire runs, it re-enqueues itself, so you still have two acquires in the queue.
Get something else in the queue, you have to get through two acquires before you get to it.
Do you see how things can slow down over time, or things wind up breaking?
