def _update_break_state(self):
        if self._break_state:
            fcntl.ioctl(self.fd, TIOCSBRK)
        else:
            fcntl.ioctl(self.fd, TIOCCBRK)
Set break: Controls TXD. When active, no transmitting is possible.
dataset/ETHPy150Open pyserial/pyserial/serial/serialposix.py/Serial._update_break_state