LABView - National Instruments
Exontrol.COM Software - Frequently Asked Questions
LAB.1:
Use the Event notification instead. The Event's ID parameter specifies the identifier of the event being fired. The EventParam(-2) gives debug information in string format about the current event.

Thanks to Johannes Reinhart, DATA AHEAD, LabVIEW Nürnberg, who submitted the note. This note is related to LABView 2013