start stop mode
The start-stop operation is an asynchronous transmission where a start bit preceding the character group sets a new time frame each time.
The start bit is followed by the character group with the information bits. Usually there are eight information bits, which together form one byte.
The receiving device uses the start bit to select the information bits and to generate the clock signal. The start-stop operation is terminated with the stop bit, which follows the parity bits. After the stop bit has been detected, the receiving device is set to the idle state and can be prepared again for the reception of the coming information bits with the following start bit.