Model Parts, Diagrams, Dictionary Items, and Properties > Properties > When (property)
  
When (property)
For automation interface information about the When property, see the automation interface topic for an Event in the Related Topics.
This property specifies the criteria to trigger the Event.
By default, the When property is blank.
This property can be set on the Options tab of the Event's Property Pages. The When box is available only when the Event Type is set to Time Event.
The following section provides information about the items and diagrams for which When is a property. For more information about an item or diagram, click it.
Is property of
Event