基于RS-485总线的多机通信系统设计及应用简介

Abstract In the field of multi-machine communication, the single-chip microcontroller is becoming more and more widely used due to its flexible, efficient, and cost-effective multi-machine communication capabilities. However, because the single-chip microcontroller has limited driving capability and anti-interference performance as the TTI level signals for transmission and reception, it is often necessary to coordinate with other buses for interconnection in practical applications, with RS-485 bus being one of them. The RS-485 bus is a balanced differential transmission, with good anti-interference performance, and can transmit up to 4000 meters, connecting up to 128 single-chip microcontrollers, making it very suitable for forming a multi-machine communication system. In multi-machine communication, the most important thing is to ensure that communication proceeds smoothly, thus requiring strict communication protocols and perfect communication software. This article will focus on introducing the application of a single-chip microcontroller multi-machine communication protocol and communication software design methods for a large-scale project. This article introduces a simple RS-485 communication network using the serial communication port provided by the single-chip microcontroller itself, utilizing a custom serial communication protocol, combined with bus drivers such as MAX481, MAX483, MAX485, MAX487, etc., to achieve communication between single-chip microcontrollers. Keywords: single-chip microcontroller; serial communication; RS-485 bus; multi-machine communication protocol.