I am relatively new to LabView (8 months programming a large project). I am trying to better understand events and how the event structure works.
I created a simple example VI which Adds two numbers and provides the result on the front panel. Within the While loop are two events that respond to the user clicking two buttons, Add Numbers and STOP. This VI is a SubVI called by a Top Level or parent VI.
Everything worked fine until I added a VI Activation event to the Event Structure in the SubVI (just to see what it did). Now when I call the SubVI, the VI Activation event is triggered and it is the first thing the subVI processes. I am calling the SubVI inline in the TopLevel VI not with an Invoke Node. The surprising thing to me is that the VI Activation event is triggered over and over once the subVI starts, even though I am NOT doing anything interactive with the Front Panel (yet) and I only call the SubVI once. Essentially the Event Structure goes into an infinite loop. Both the Event Source and Type are numeric data types and my probes tell me that Source and Type are both set to zero when the VI Activation Event is triggered. I can't find a list of Type numbers to know how to translate the numeric value into an event. Is there a list of Type numbers and their corresponding event?
I assume that zero means that nothing specific triggered the VI Activation event, but if the event type is zero, I don't understand why the VI Activation is triggered in the first place, much less repeats. There isn't much information on the VI Activation event in the Forums or NI documentation and I can't find any examples to show how VI Activation is supposed to work. From the meager information I have found, I thought the VI Activation event was triggered only when the user interacted (in some way) with the UI. Can someone provide more insight?
Unfortunately my company does not permit me to upload any code (I am currently signed in with my personal account), but I am including a screen capture of the block diagram.
