A Simulink® Identifier (SID) is a unique and unmodifiable designation automatically assigned to a Simulink block, model annotation, or Stateflow® object within a Stateflow chart. The SID helps to identify specific instances of these components in your diagram, especially when sharing models between people within a team.
The SID has these characteristics:
Persistent within the lifetime of a Simulink block, model annotation, or Stateflow object
Saved in the model file
Remains the same if the block or object name changes
Cannot be modified
The SID format is:
model_name is the name of the model where the block, annotation,
or Stateflow object resides.
sid_number is a unique number within the model, assigned by
The SID includes additional colons in certain cases, for example on an instance of a block from a user library.