> "National Instruments recommends that you place only one Event > structure in a loop. When an event occurs in this configuration, the > Event structure handles the event, the loop reiterates, and the Event > structure waits for the next event to occur. If you place two Event > structures in a single loop, the loop cannot reiterate until both > Event structures handle an event. If you have enabled front panel > locking for the Event structures, the user interface of the VI can > become unresponsive depending on how the user interacts with the front > panel." > > There are other details in the help listing including a deadlock > condition caused by a double-click.
These caveats should be updated to more specifically warn against this for statically registered event structures. An event structure working with dynamically registered events can reside anywhere you want, even beside another one. You can even place them inside one another, but you had better know what you are doing there. The problem with statically registered events is that any and all event structures on the diagram are always registered, even before they run the first time and after they run the last time. This feature means that you don't miss events. The problem is that when the panel locks waiting for an event to be processed, and your diagram isn't going to process the event, what happens then. Fortunately, the Abort button should always work, even on locked panels. Greg McKaskle
