def _connect_control(self, event, param, arg):
        """
        Is the actual callback function for :meth:`init_hw_connect_control_ex`.

        :param event:
            Event (:data:`CbEvent.EVENT_CONNECT`, :data:`CbEvent.EVENT_DISCONNECT` or
            :data:`CbEvent.EVENT_FATALDISCON`).
        :param param: Additional parameter depending on the event.
        - CbEvent.EVENT_CONNECT: always 0
        - CbEvent.EVENT_DISCONNECT: always 0
        - CbEvent.EVENT_FATALDISCON: USB-CAN-Handle of the disconnected module
        :param arg: Additional parameter defined with :meth:`init_hardware_ex` (not used in this wrapper class).
        """
        log.debug("Event: %s, Param: %s" % (event, param))

        if event == CbEvent.EVENT_FATALDISCON:
            self.fatal_disconnect_event(param)
        elif event == CbEvent.EVENT_CONNECT:
            self.connect_event()
        elif event == CbEvent.EVENT_DISCONNECT:
            self.disconnect_event()