def start(self, func=None):
self._user_callback = func<EOL>if not self._simulate:<EOL><INDENT>self._process = ControlProcess(self._conn, self._config, self._q,<EOL>self._log, callback=self._callback)<EOL><DEDENT>else:<EOL><INDENT>self._process = MockProcess(self._config, self._q,<EOL>self._log, callback=self._callback)<EOL><DEDENT>self._process.start()<EOL>self._roasting = True<EOL>
Start the roaster control process.

        This function will kick off the processing thread for the Hottop and
        register any user-defined callback function. By default, it will not
        begin collecting any reading information or saving it. In order to do
        that users, must issue the monitor/record bit via `set_monitor`.

        :param func: Callback function for Hottop stream data
        :type func: function
        :returns: None