History Junction
R2026bJunction that records and restores the previously active substate when a superstate is reentered
Description
A history junction records the previously active substate inside a superstate that uses exclusive (OR) decomposition, then restores that substate when the superstate is reentered. The first time a superstate that contains a history junction becomes active, the chart executes the default transition to determine which substate to enter. Each subsequent time the superstate becomes active, the chart enters the substate that was active when the superstate last became inactive, bypassing the default transition. A state cannot have more than one history junction. You cannot use history junctions at the chart level, inside states with parallel (AND) decomposition, or inside graphical functions.
A history junction accepts incoming transitions. Connecting a transition to a history junction causes the chart to exit and reenter the currently active substate. For more information, see Resume Prior Substate Activity by Using History Junctions.
To add a history junction to a chart:
In the object palette, click the History Junction icon
.In the chart canvas, click inside the state where you want to place the history junction.
After you add a history junction, select it and use the Format tab in
the toolstrip to resize it. To modify history junction properties programmatically, use
Stateflow.Junction objects with
the Type property set to "HISTORY".
Properties
Version History
Introduced before R2006a
