Why can't I find a 'Stateflow.EMChart' behind a masked library block?

I have a model and a custom library. The custom library contains a masked subsystem, within which is a 'MATLAB Function Block'. I have placed an instance of the masked subsystem into my main model.

Before I moved the masked subsystem into the library, I used the following command to get the 'MATLAB Function Block' as a 'Stateflow.EMChart':

block = find(get_param(block_name, "Object"), '-isa', 'Stateflow.EMChart');

But now that I am using the masked subsystem as a library block, the above command returns an empty cell array. To get a value again, I have to first call

set_param(gcb,'LinkStatus','none');

to disable the masked subsystem's library link.

Disabling the library link is not ideal. Is there a way I can find the 'Stateflow.EMChart' without disabling the link?

Answer 1

[MathWorks Support Team]

Disabling the link status of the library block is the only way to access the 'Stateflow.EMChart' of the 'MATLAB Function Block' with this configuration of blocks.

In general, accessing a 'Stateflow.EMChart' behind a mask is not a recommended practice as it goes against model-based-design principles. Instead, it is recommended to use 'Variant Systems' to accomplish the behavior you have described.

You can learn more about 'Variant Systems' at the link below:

https://www.mathworks.com/help/simulink/variant-systems.html