A Simulink® function is a graphical object that you fill with Simulink blocks and call in the actions of states and transitions. Simulink functions are not supported in standalone Stateflow® charts in MATLAB®. For more information, see Reuse Simulink Functions in Stateflow Charts.
The goal of this tutorial is to use
Simulink functions in a Stateflow chart to improve the design of a
model contains a Stateflow chart and three function-call
subsystems. These blocks interact as
The chart broadcasts the output events
A3 to trigger the function-call
The subsystems A1, A2, and A3 execute at different rates defined by the chart.
The subsystem outputs feed directly into the chart.
No other blocks in the model access the subsystem outputs.
You can replace function-call subsystems with Simulink functions inside a chart when:
The subsystems perform calculations required by the chart.
Other blocks in the model do not need access to the subsystem outputs.
The sections that follow describe how to replace function-call subsystem blocks in a Simulink model with Simulink functions in a Stateflow chart. This procedure reduces the number of objects in the model while retaining the same simulation results.
|1||Open the model.||Open the Model|
|2||Move the contents of the function-call subsystems into Simulink functions in the chart.||Add Simulink Functions to the Chart|
|3||Change the scope of specific chart-level
data to ||Change the Scope of Chart Data|
|4||Replace event broadcasts with function calls.||Update State Actions in the Chart|
|5||Verify that function inputs and outputs are defined.||Add Data to the Chart|
|6||Remove unused items in the model.||Remove Unused Items in the Model|
To skip the conversion steps, you can access the new model directly.
model. If you simulate the model, you see this result in the scope.
For more information, see Schedule Subsystems to Execute at Specific Times.
Follow these steps to add Simulink functions to the Temporal Logic Scheduler chart.
In the Simulink model, right-click the A1 block in the lower right corner and select Cut from the context menu.
Open the Temporal Logic Scheduler chart.
In the chart, right-click outside any states and select Paste from the context menu.
Expand the new Simulink function so that the signature fits inside the function box.
To change the font size of a function, right-click the function box and select a new size from the Font Size menu.
Rename the Simulink function from
f1 by entering
f1(u) in the function box.
Repeat steps 1 through 5 for these cases:
Copying the contents of A2
into a Simulink function named
Copying the contents of A3
into a Simulink function named
The new functions reside at the chart level
because both states
SlowScheduler require access to
the function outputs.
In the Model Explorer, change the scope of
Local because the
calculation for that data now occurs inside the
In the Stateflow Editor, you can replace event broadcasts in state actions with function calls.
Edit the state actions in
SlowScheduler to call the
In both states, update each
during action as
du: y = u1-y2;
on every state
SlowScheduler, define three
data. (For details, see Add Stateflow Data.)
Add local data
y2 to the chart.
Add output data
y3 to the
In the model, connect the output for
y3 to the scope.
To flip the Scope block, select the block. Then, in the toolstrip, on the Format tab, click Flip left-right .
In the Model Explorer, delete output events
A3 and input data
u2 because the function-call
subsystems no longer exist.
Delete any dashed signal lines from your model.
Your new model looks something like this:
If you simulate the new model, the results match those of the original design.