The goal of this tutorial is to use Simulink® functions
in a Stateflow® chart to improve the design of a model named
sf_temporal_logic_scheduler model contains
a Stateflow chart and three function-call subsystems. These blocks
interact as follows:
The chart broadcasts the output events
A3 to trigger the function-call subsystems.
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 and access the new model directly,
the MATLAB command prompt. 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.
Tip 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
y = f1(u) in the function box.
Repeat steps 1 through 5 for these cases:
Copying the contents of A2 into a Simulink function
Copying the contents of A3 into a Simulink function
The new functions reside at the chart level because both states
In the Model Explorer, change the scope of chart-level data
the calculation for that data now occurs inside the chart.
In the Stateflow Editor, you can replace event broadcasts in state actions with function calls.
Edit the state actions in
call the Simulink functions
In both states, update each
du: y = u1-y2;
on every state actions of
define three data. (For details, see Add Stateflow Data.)
Add local data
Add output data
y3 to the chart.
In the model, connect the outport for
the inport of the scope.
Tip To flip the Scope block, right-click and select Rotate & Flip > Flip Block from the context menu.
In the Model Explorer, delete output events
A3 and input data
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.