When a transition is disabled, it always evaluates to False when it is active. This way, you can control the flow through an SFC by keeping all the steps prior to the disabled transition active and all of the steps that follow it inactive. A disabled transition can stop the flow through a particular branch of a sequence select divergence in the SFC. This keeps the steps that precede this transition active, and the actions continue to be evaluated according to the action qualifier of each. In addition, a disabled transition keeps the steps that follow the transition from going active.
The online view shows the value that the disabled transition would have if it were not disabled.
When you want to hold an SFC where it currently is, disable all active transitions and active steps.
Any active transition, whether enabled or disabled, can be forced to True by clicking . If you disable all of the transitions, you can then step through the SFC by forcing transitions when required. You can also disable a single transition to force the SFC down another branch of a sequence select divergence.