Most transitions are from one state to another. This is not the
case with self-transitions.
A self-transition, is one in which the source state and the target
state are the same. There are two kinds of self-transitions.
- External transition
- In an external transition, all entry and exit actions are invoked during
execution, and a change of state is registered.
- Internal transition
- An internal transition does not allow the exit and entry actions to be
executed. An internal transition's triggering event must be either a call
event or a timer event. Also, composite states cannot define internal transitions.
- Drop a state onto the canvas.
- Move the cursor over the state until the yellow "lollipop" appears
above it as shown in this image.

- Hold the left mouse button. The cursor will change appearance,
and will look like a crossed out circle.
- Drag the cursor out over the canvas. When you hover
over a valid target, the crossed out circle disappears.
- Click the same state from which you are linking. A triangular
transition will appear that indicates that you are creating a loop, and linking
back into the same state.

- By default, this is considered to be a external transition. To
make it an internal transition, click the Description tab
in the Properties area, and enable the Internal check
box.