Inconsistent behavior when using "set_param" to set mask parameter values

When I use "set_param" to modify the value of a mask parameter, I found that the success of the modification depends upon:

- whether the mask dialog is open or closed before calling "set_param".

- whether the mask dialog is open or closed after calling "set_param" and before saving a model.

- whether the mask parameter is visible or invisible.

In R2022a, the "set_param" call will modify the model only if the mask dialog is not open. If the mask dialog is open, it may intercept the "set_param" call depending on whether or not the parameter is visible.

I also found that the exact behavior has changed from release to release (changed from R2019b to R2020a and then reverted back from R2021b to R2022a). How can I avoid this inconsistent behavior?

Answer 1

[MathWorks Support Team]

To set mask parameter values, please use "Simulink.Mask" and "Simulink.MaskParameter" classes instead of the "set_param" function. Utilizing these classes to change mask parameters will set/change the parameters, independent of the MATLAB version, whether the parameters are hidden/visible, the mask dialog is open or not.

The following demonstrative piece of code sets the value of a parameter "anyPar" for a masked subsystem "SubSys'" in the model "TestModel":

%Get Subsystem Mask
p = Simulink.Mask.get('TestModel/SubSys');

%Get Parameter from Mask
q = p.getParameter(anyPar);

%Set Parameter Value
q.set('Value','NewValue');

 

This method is based on the following documentation pages:

https://www.mathworks.com/help/simulink/ug/control-masks-programmatically.html

https://www.mathworks.com/help/simulink/slref/simulink.mask-class.html

https://www.mathworks.com/help/simulink/slref/simulink.maskparameter-class.html