In a Simulink® model, when a Stateflow® chart is enabled by a function-call input event, you can control the state of the chart by setting the States When Enabling chart property. This property determines the values of states and data when the input event reenables the chart:
Held
— Maintain most recent values of the states and data.
Reset
— Revert to the initial values of the states and data.
For new charts, the default setting is Held
. For more information, see Activate a Stateflow Chart by Sending Input Events.
In this model, the Caller
chart uses the event E
to wake up and execute the Callee
chart.
The Caller
chart contains two states, A
and B
. When you bind the output event E
in state A
:
Entering A
enables the Callee
chart.
Exiting A
disables the Callee
chart.
Reentering A
reenables the Callee
chart.
The temporal logic operator after changes the active state every ten time steps, so the Callee
chart is repeatedly enabled and disabled.
The Callee
chart contains two states, C
and D
. Each time that the chart executes, the output data y
increments by one. The state C
is initially active. After one time step, the value of y
is positive and the chart takes the transition to state D
.
Held
In the Callee
chart, the States When Enabling property is set to Held
. During simulation, when the function-call input event reenables the chart at times and
, state
D
stays active and output y
maintains its most recent value.
Reset
In the Callee
chart, change the States When Enabling property to Reset
. During simulation, when the function-call input event reenables the chart at times and
, state
C
becomes active and output y
reverts to its initial value of zero.