When you use active state output to monitor child activity, the output data is an enumeration. Stateflow® will automatically create this enumeration, or you can customize it.
In the enumeration definition, there must be one literal for each state name plus an extra literal to indicate no active child.
For example, here is the enumeration definition for the output of gear_state in the model sf_car.
enumeration None(0), first(1), second(2), third(3), fourth(4) end
You can customize the name and definition for the enumeration output in the Properties window. To customize the name, type the new name in the edit box next to Enum name. Stateflow will automatically create this enumeration, or you can tell Stateflow to use an existing definition by selecting Fetch enum definition from MATLAB.
If you select Fetch enum definition from MATLAB, but no definition exists, then Stateflow provides a link to automatically create a MATLAB® definition. Selecting, Create enum definition from template, automatically generates an enumeration definition in a .m file. You can then customize this definition.
In the example, sf_car, the port name is named gear, and the enumeration type is gearType.