You can configure a subsystem to execute either conditionally or unconditionally.
An unconditionally executed subsystem always executes.
A conditionally executed subsystem executes based on the value of an input signal. For details, see Conditionally Executed Subsystems and Models.
Select the Subsystem block.
Select one of the labeling options from Diagram > Format > Port Labels menu (for example,
Port Block Name).
You can control user access to subsystems. For example, you can prevent a user from viewing or modifying the contents of a library subsystem while still allowing the user to employ the subsystem in a model.
This method does not necessarily prevent a user from changing the access restrictions. To hide proprietary information that is in a subsystem, consider using protected model referencing models (see Reference Protected Models from Third Parties).
To restrict access to a library subsystem, open the subsystem parameter dialog box and set Read/Write permissions to one of these values:
ReadOnly: A user can view the contents
of the library subsystem but cannot modify the reference subsystem
without disabling its library link or changing its Read/Write
NoReadOrWrite: A user cannot view
the contents of the library subsystem, modify the reference subsystem,
or change reference subsystem permissions.
You do not receive a response if you attempt to view the contents
of a subsystem whose Read/Write permissions parameter
is set to
NoReadOrWrite. For example, when
double-clicking such a subsystem, Simulink does not open the
subsystem and does not display any messages.
You can use block callbacks to perform actions in response to subsystem modeling actions such as:
Handling an error
Deleting a block or line in a subsystem
Closing a subsystem
For details, see Specify Block Callbacks.