Hello everyone, welcome to the Star Instrument Classroom, in this issue, we will talk about the working principle of RS485 communication. Let’s talk about the following 6 aspects: 1. Differential signaling is adopted. The biggest advantage of differential signals is that common-mode interference can be suppressed. Especially when the industrial site environment is complex and there is a lot of interference, the differential mode can effectively improve the communication reliability. RS485 uses two communication lines, usually represented by A and B or D+ and D-. Logic “1” is represented by the voltage difference between the two wires is +(2~6)V, and logic “0” is represented by the voltage difference between the two wires is -(2~6)V, which is a typical differential communication.

　　2. RS485 communication rate is fast, and the maximum transmission speed can reach more than 10Mb/s. 3. The internal physical structure of RS485 adopts a combination of balanced driver and differential receiver, and the anti-interference ability is also greatly increased. 4. The transmission distance can reach about 1200 meters, but its transmission rate is inversely proportional to the transmission distance, only at the transmission speed below 100Kb/s, the maximum communication distance can be reached, and the repeater can be used if you need to transmit a longer distance. 5. It can be networked on the bus to achieve multi-machine communication, and multiple transceivers are allowed to be hung on the bus, and from the existing RS485 chip, there are drivers that can hang 32, 64, 128, 256 and other different devices. 6. The interface of RS485 is very simple, only one RS485 converter is needed, it can be directly connected with the serial port of the single-chip microcomputer, and the same asynchronous serial communication protocol is used. However, since RS485 is a differential communication, it is not possible to receive data and send data at the same time, that is to say, it is a half-duplex communication. Star Meter Manufacturing Co., Ltd. is a high-tech enterprise integrating R&D, production and sales. Specializing in the production of pressure transmitters, liquid level transmitters, temperature transmitters, temperature and humidity transmitters, differential pressure transmitters, soil moisture transmitters, 3051 transmitters and related instrumentation accessories. A number of products under the Xingyi brand have obtained a number of patent certificates issued by the state, such as CE certification, IS9001 certification, SGS certification, TüV SüD certification, explosion-proof certification, etc. If you have any questions about product consultation, product customization, agency, technical inquiry, quotation, etc., please contact Xingyi: 400-600-4496!