What determines when an actor FP opens and closes?

[BillMe]

I use Launch Nested Actor exclusively with the Open Actor Front Panel input set to FALSE and Auto Stop defaulted to TRUE. I have three actors that the user interacts with through their respective front panel. Two of the actors behave differently from the third (UI actor) when it comes to the front panel open/close behaviour..

VI #1 opens its front panel when launched (on its own) and when receiving the stop message, remains open. I don't use the FP.Open (Standard State) on this VI. This happens in development or in the executable.

VI #2 opens its front panel after launching when I use the FP.Open in Standard State as expected. But when it receives a Stop message, the clone goes away, but the base VI front panel then opens up (in development mode, the FP remains open in the executable).

This behaviour differs from my UI actor which I open with FP.Open in Standard State, and upon receiving the Stop message, it's front panel closes normally without me using FP.Open Hidden state.

The "Window Appearance-->Show Front Panel when called" is NOT checked on either VI.

I can add an FP.Open Hidden state and hide the front panels when stopping. But why didn't I have to do that for my UI actor? And why does VI #! open on its own?

[justACS]

You can set an actor's front panel to open in one of three ways.  You can

1. use the Open Actor Front Panel input to Launch Actor (not recommended)
2. configure that actor's front panel to Show Front Panel When Called or When Loaded
3. use VI Server calls to open and close the panel

The common thread in these choices that you have to make a specific choice.  If you don't do one of those three things, the panel should not open.

I have no idea why actor 1 behaves as it does.  It sounds like one of the Show Front Panel options was selected, but you say that hasn't happened.

For actor 2, it sounds like you've left the source code front panel open.

Whatever is going on, though, I can assure you that there is no hidden behavior in AF to cause these inconsistencies.

I would also recommend using FP.Close, not FP.Open (Hidden) when closing your actor.

[BillMe]

I should have started this on the LabVIEW forum (and I may still), but I was seeking verification on the Auto Open FP. Didn't mean to imply any issue with AF.

All three have an FP.Close in the appropriate place now and upon exit, everything looks nominal, however, the one actor (my main UI) will close without it.