...
Note that some of these are directly I/O related, and some are not. For example, the hotbutton hotswitch events are not, meaning that a hotbutton hotswitch can be configured to launch a user-created program (but see note below regarding hotswitch events).
Callbacks Panel
Shows the callbacks that are associated with the currently selected event in the Events panel. Note that the Enable checkbox applies to all events, not just the currently selected one. The Add pushbutton is used to select a userFcn file (a Matlab script or function with the *.m extension), which then appears in the listbox; the Delete function removes the entry.
...
Arguments for the selected userFcn.
Notes
When a hotswitch is newly configured (i.e. named and tied to a directory), an event is created that will fire whenever the hotswitch button is clicked. However, you may need to force the Events list to refresh, in order to display this newly created event. To do this, simply select any item in the Events list, other than the currently selected item. This will cause the list to refresh, and the new hotswitch event will appear.