In UML modeling, a signal trigger represents a specific
message that initiates a transition when an object receives it.
Before you can add a trigger to a transition,
you must have a state machine diagram open in the Modeling perspective.
To add a signal trigger to a transition, right-click a
transition; then click , and complete
one of the following:
- Click Create New Signal,
type a name and press Enter.
- Click Select Existing Element,
in the Select Element window, in the list click
a signal, and click OK. Type a name and press
Enter.