Design of an Intelligent Instrument Communication System Based on RS485 Bus

RS485 has high applicability as a communication interface, and plays an important role in industrial control, instrumentation and instrumentation mechatronics. Based on RS485, this paper studies the communication problem between PC and smart device. By studying the serial communication protocol and analyzing the electrical characteristics of RS485, compared with RS232, it has a strong advantage in the field of industrial control. RS485 uses the Modbus protocol. When communicating on the Modbus network, this protocol determines that each controller needs to know their device address, recognize the message sent by the address, and decide what action to generate. Extend VB6.0 to develop a microcomputer MSComm communication control with a serial port to use with ActiveX controls, real-time data collection of smart meters, data collection of smart meters, and programming technology for monitoring. RS485 has the advantages of excellent performance and simple network. It is widely used in centralized and distributed control systems, especially for applications that require long-distance transmission.