Scope and hierarchy of variables in Simulink

Is there any documentation on variable scope in Simulink. My understanding is that lower level units like masked subsystems have visibility of what I would regard as higher level areas like the model workspace, but the insides of masked subsystems are not visible to global models.

I'm struggling with this a bit because in most programming languages re-usable sub-units have limited scope. For example, a Matlab function would not be able to see the workspace of the calling function, or the Matlab workspace for that matter. On the other hand, a masked Simulink subsystem can see the Simulink workspace.

In the case of conflicts, what takes precidence? For example if I name a mask parameter VAR1 and I also have a variable in the Simulink workspace called VAR1 and a data dictionary entry called VAR1, and a Matlab workspace VAR1, which value is used? (This is the reason I'm asking the question.)

Is there a way to limit the scope of a masked subsystem? For example I see that it is possible to restrict a Simulink model such that it cannot access the Matlab workspace. I can't see similar functionality for masks.

Sorry if this is all obvious. Not easy to search the internet when most hits are related to Simulink scope blocks, ie for viewing signals.

[men8th]

Possibly answering my own question...

• https://blogs.mathworks.com/simulink/2009/02/15/where-does-that-variable-come-from/?s_tid=answers_rc2-3_p6_Topic
• https://uk.mathworks.com/help/simulink/ug/resolving-symbols.html