How to add data in stateflow by using the API ?

I want to add a stateflow constant data by API. Is it possible?

I am doing SIL testing and would like to modify some constant data through the stateflow API.

Answer 1

[MathWorks Support Team]

Yes! It is possible.

Please go through the code below to have a better understanding of the commands.

% This script demonstrates simple example of using the statefloew API.
% For more details about the stateflow commands please go through the
% documentaion online

clear;
bdclose('all'); % Close all models
clc;

%%First create a new model 
sfnew; % Creates a new model with a new stateflow chart in it

%%Access the model object created
rt = sfroot;

m = rt.find('-isa','Simulink.BlockDiagram');

%%Access the stateflow object in the model

ch = m.find('-isa','Stateflow.Chart');

% Create new states A and B in stateflow
state_A = Stateflow.State(ch);
state_A.Name = 'A';
state_A.Position = [80 120 90 60];

state_B = Stateflow.State(ch);
state_B.Name = 'B';
state_B.Position = [240 120 90 60];

% Create a transition
trans_A2B = Stateflow.Transition(ch);
trans_A2B.Source = state_A;
trans_A2B.Destination = state_B;
trans_A2B.SourceOClock = 3;
trans_A2B.DestinationOClock = 9;

% Add a default transition to state A
default2A = Stateflow.Transition(ch);
default2A.Destination = state_A;
default2A.DestinationOClock = 0;

%%Add input/output and parameters and constants to the chart
% Add an input in1
data_in = Stateflow.Data(ch);
data_in.Scope = 'Input';
data_in.Name = 'in1';

% Add an output out1
data_out = Stateflow.Data(ch);
data_out.Scope = 'Output';
data_out.Name = 'out1';

% Add a constant Param1
data_param = Stateflow.Data(ch);
data_param.Scope = 'Parameter';
data_param.Name = 'Param1';

% Add a constant Const1
data_const = Stateflow.Data(ch);
data_const.Scope = 'Constant';
data_const.Name = 'Const1';
data_const.Props.InitialValue = '17';       % => Change the constant initial value here

% Open the stateflow chart for view
ch.view;

%%Save the model with any name you want
sfsave;

Also, some type of variables like the constant type can only be set before the simulation starts. If you are trying to dynamically change the read-only variables during the simulation for the SIL then, you might get an error. Please see relevant documentation linked below for read-only variable types:

Manage Data::

https://www.mathworks.com/help/releases/R2019a/stateflow/ug/use-the-symbols-window-with-stateflow-data-events-and-messages.html#bvfv6_u-1

Set Data Properties:

https://www.mathworks.com/help/releases/R2019a/stateflow/ug/set-data-properties-1.html#bqlgn92