How to specify internal transitions in state diagrams?

General Questions/Discussions
1

I’m evaluating VP-UML, working with State Machine Diagrams. I can’t figure out out to specify an internal transition so that it appears inside the State icon (the rounded rectangle labeled with the state name).

Definition of an Internal Transition: An internal transition is an event/trigger that has an action associated with it but does not lead to a change of state (state transition). An internal transition may have a guard associated with it.

Expected Notation: In UML, the notation for an internal transition follows the general syntax used for exit or entry actions, except that instead of the word “entry” or “exit”, the internal transition is labeled with the triggering event (some tools will prefix the word “event” in front of the triggering event). An event/trigger may have arguments associated with it.

For example, a State with an Entry action, Exit action, and Internal transition (with guard and event arguments) might be shown as follows:

State1

entry/Action 1
exit/Action 2
event MyEvent1(arg1, arg2) / [arg1 > 0]/Action 3

2

Hi Michael,

To specify internal transitions in VP-UML, you need to add a region to the State first, and then specify the internal transitions in the Open Specification of the region.

To add a region to a State, right-click on the State and select Add Horizontal/Vertical Region.

Hope this helps. Please feel free to let me know if there are any questions.

Best Regards,
Jick