RS485 bus-based communication terminal system

Abstract

The invention discloses a RS485 bus-based communication terminal system, the terminal system is composed of a MCU part, an isolation and level transformation part and a transceiver part. The MCU takescharge of receiving and transmitting of data and control of the transceiver, the isolation and level transformation part realizes electric isolation between the MCU and the transceiver and level transformation of the MCU, and the transceiver realizes transformation of a RS485 level and a TTL level; a fast resettable fuse is used at the RS485 bus end so as to prevent burning a bus port by short circuit of the bus, and a voltage dependent resistor and a transient voltage suppressor are used for absorbing overcurrent and overvoltage. A RS485 bus terminal is designed by the invention, an AMD2582Ewith a magnetic isolation technology is used as a bus controller, photoelectric isolation and a level transformation technology are used between a singlechip microcomputer and the bus controller, andtransformation of different levels and signal isolation are realized.

Description

technical field [0001] The invention relates to the field of intelligent communication, in particular to a communication terminal system based on RS485 bus. Background technique [0002] The RS485 bus is widely used in industrial sites because of its simple wiring, stability and reliability. However, there are many sources of interference in industrial sites. In order to ensure the reliability of the system, the bus terminal needs to adopt multiple anti-interference methods such as photoelectric isolation and electromagnetic isolation. At the same time, it also considers the protection of the bus terminal in terms of overvoltage and lightning strike protection. The current communication terminal protection and stability are not good. Contents of the invention [0003] The purpose of the present invention is to provide a communication terminal system based on RS485 bus which is simple in structure, simple in wiring, stable and reliable. [0004] In order to solve the probl...

AI Technical Summary

Problems solved by technology

[0002] The RS485 bus is widely used in industrial sites because of its simple wiring, stability and reliability. However, there are many sources of interference in industrial sites. In order to ensure the reliability of the system, the bus terminal needs to adopt multiple anti-interference methods such as photoelectric isolation and electromagnetic isolation. At the same time, the protection of the bus terminal in terms of overvoltage and lightning strike protection is also considered. The protection and stability of the current communication terminal are not good.

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