Every user-written S-function must implement a set of methods, called callback methods or simply callbacks, that Simulink invokes when simulating a model that contains the S-function. Some callback methods are optional. Simulink invokes an optional callback only if the S-function defines the callback. This section describes the purpose and syntax of all callback methods that an S-function can implement. In each case, the documentation for a callback method indicates whether it is required or optional.
