Referencing Implicit Events :: Defining Events and Data (Stateflow User's Guide)

Stateflow User's Guide

Referencing Implicit Events

Action expressions can use the following syntax to reference implicit events.

```
event(object)
```

where event is the name of the implicit event and object is the state or data in which the event occurred.

Each of the following keywords generates implicit events in the action language notation for states and transitions.

Implicit Event
Meaning

change(data_name) or
chg(data_name)
Specifies and implicitly generates a local event when the value of data_name changes.

enter(state_name)
en(state_name)
Specifies and implicitly generates a local event when the specified state_name is entered.

exit(state_name)
ex(state_name)
Specifies and implicitly generates a local event when the specified state_name is exited.

tick
Same as wakeup keyword.

wakeup
Specifies and implicitly generates a local event when the chart of the action being evaluated awakens.

Implicit Event	Meaning
`change(data_name)` or `chg(data_name)`	Specifies and implicitly generates a local event when the value of `data_name` changes.
`en`ter(`state_name`) `en(state_name)`	Specifies and implicitly generates a local event when the specified `state_name` is entered.
`exit`(`state_name`) `ex(state_name)`	Specifies and implicitly generates a local event when the specified `state_name` is exited.
`tick`	Same as `wakeup` keyword.
`wakeup`	Specifies and implicitly generates a local event when the chart of the action being evaluated awakens.

If more than one object has the same name, the event reference must qualify the object's name with that of its ancestor. The following are some examples of valid implicit event references.

enter(switch_on)
en(switch_on)
change(engine.rpm)

Note The wakeup (or tick) event always refers to the chart of the action being evaluated. It cannot reference a different chart by argument.

Defining Implicit Events Example of an Implicit Event