How To Dynamically Change States In Stateflow?

One way to change the states is by connecting a transition from source state to the destination state. I was wondering if there's a way to transition to another state by calling a function or by changing some state property. The Idea here is that i have a state flow sub chart that needs to connect to many different states in the main chart. Before jumping into the sub chart let check this Custom Lithium Ion Battery Pack Manufacturer, I would like to save the next state in a variable and set to that state on exit of the sub chart . My desired behavior:

Name: Last_State_In_Subchart

Entry:SetNextState(SavedState);

Is there a way to do this?

Answer 1

[Purvaja]

Hey @Ben,

I understand that you want to transition between states based on certain conditions by storing the desired state in a variable and triggering the transition accordingly. However, instead of storing values in a variable, the more appropriate way would be to use “junction” block in Stateflow (Simulink).

In the scenario you described—connecting a Stateflow subchart to multiple states in the main chart—I implemented an example with three states: A, B, and C, where state B contains a subchart named S. This subchart transitions to either state A or state C, based on which condition is satisfied, using conditional paths defined at a junction.

Refer to the below diagrams for more clarifications on the Stateflow chart and how the result is achieved. Variable ‘x’ is an input variable, with ‘y’ and ‘state’ are output variables:

1. Simulink Model consisting of dummy signals, showing input and output of “Stateflow” block:
2. Stateflow diagram indicating states and sub-states, along with transition conditions:

For more clarifications related to “Junction” block in Simulink, kindly refer to the following MathWorks documentation links:

https://www.mathworks.com/help/stateflow/ug/connective-junctions.html

To access the documentation for the MATLAB release you are using, please execute the following command in the MATLAB command window:

web(fullfile(docroot, 'stateflow/ug/connective-junctions.html')) 

More workarounds:

1. Using state Transition table:

You can use transition tables too to create transitions to different state using if-else conditions.

Refer to this link for documentation: https://ww.mathworks.com/help/stateflow/ug/modeling-a-cd-player-radio-using-state-transition-tables.html

Access using this command for an example in your MATLAB command line:

openExample('stateflow/ModelingACdPlayerradioUsingStateTransitionTableExample')   

2. Using Stateflow Programmatic Interface:

Programmatically call the states and their transitions by using Stateflow API or MATALB script.

Refer to this link for documentation: https://www.mathworks.com/help/stateflow/programmatic-interface.html

Refer to this link for commands: https://www.mathworks.com/help/stateflow/api/quick-start-for-the-stateflow-api.html

Hope this helps you!