What is Serial Communication Protocol?
At first, the data was a simple process quantity of analog signal output. Later, the RS232 interface appeared in the instrument interface. This interface can realize the point-to-point communication method, but this method cannot realize the networking function, which promotes the RS485.
At first, the data was a simple process quantity of analog signal output. Later, the RS232 interface appeared in the instrument interface.
We know that the data transmission of serial communication is 0 and 1. In single bus, I2C, UART, the logic 1 or logic 0 is judged by the high and low level of a line, but the GND of this signal line is connected with other devices. Communication in the common ground mode is formed. This common ground mode transmission is prone to interference, and the anti-interference performance is relatively weak.
Therefore, RS485, which supports differential communication, supports multi-machine communication, and has strong anti-interference, is widely used. The biggest feature of RS485 communication is that the transmission speed can reach more than 10Mb/s, and the transmission distance can reach about 3000 meters.
RS485, which supports differential communication, supports multi-machine communication, and has strong anti-interference, is widely used. The biggest feature of RS485 communication is that the transmission speed can reach more than 10Mb/s
It should be noted that although the maximum speed of 485 and the maximum transmission distance are very large, the transmission speed will slow down as the distance increases, so the two cannot be used at the same time.
