Use callback tracing to determine the callbacks that Simulink® invokes and the order that it invokes them when you open, edit, or simulate a model.
To enable callback tracing, do one of the following:
In the Simulink Preferences dialog box, select the Callback tracing preference.
Execute set_param(0, 'CallbackTracing', 'on').
The CallbackTracing parameter causes the callbacks to appear in the MATLAB® Command Window as they are invoked. This option applies to all Simulink models, not just models that are open when you enable the preference.