You can configure the Event Structure to handle events from any supported source.
User Interface—mouse clicks, key presses, and so on.
External I/O—hardware timers or triggers that signal when acquisition completes or when an error condition occurs.
Programmatically generated events—events triggered by diagram code, without any user interaction.
Each event is associated with a control on the panel of the VI, the panel window of the VI, a pane of the VI, or the application.
The application generates events for a VI only while that VI runs or when another running VI calls that VI as a subVI.