'Set terminal status line: Data Terminal Ready.'

def _update_dtr_state(self):

    if (not self.is_open):
        raise portNotOpenError
    if self.logger:
        self.logger.info('set    DTR    to    {}'.format(('active' if self._dtr_state else 'inactive')))
    if self._dtr_state:
        self.rfc2217_set_control(SET_CONTROL_DTR_ON)
    else:
        self.rfc2217_set_control(SET_CONTROL_DTR_OFF)
