The reference network is organized as follows
1. 8N1: Each data transfer uses 10 bits, 1 start bit, 8 data bits, and 1 stop bit
8: Indicates 8-bit data bit
N: Indicates (NO parity), that is: no parity
1: Indicates a stop bit
Note: Start bit: The start bit must be a logic 0 level lasting one bit time
Stop bit: keep a low level. Used to indicate the last bit of a single packet. Typical values are 1, 1.5 and 2 digits. Since the data is timed on the transmission line, and each device has its own clock, it is very likely that there is a small out-of-synchronization between the two devices in the communication. Therefore, the stop bit not only indicates the end of the transmission, but also provides an opportunity for the computer to correct clock synchronization. The more the number of bits applicable to the stop bit, the greater the tolerance for synchronization of different clocks, but the slower the data transmission rate is at the same time.