基于RS485总线的远程测量系统（终稿）精选.doc

摘要 　　RS-485总线由于采用平衡发送、差分接收的方式，以共模抑制能力强，灵敏度高，传输距离远，传输速率高的特点在远程通讯、远程测量中已得到广泛应用，尤其是在控制领域，将各种控制信息通过RS-485总线实现远距离的监测和控制。 　　本文主要介绍单片机与微机通过RS-485串行总线进行远程通信的测量系统的设计，包括一台PC作为主机进行数据的处理和多个AT82S52单片机作为从机进行实时的温度测量，从机是由DS18B20温度传感器与AT89S52单片机组成一个简单、实用的实时温度测量系统，从机可以进行独立测量，并且将实时测量的温度信息通过具有485总线接口的MAX485芯片将数据传送给主机PC机处理，以实现远距离的实时监控和数据的远距离传输。整个系统设计简单、使用灵活方便、价格低廉，且能够直接输出数字量、因此具有很强的实用性。 　　 关键词：远程测量；RS-485; 单片机；异步通讯；DS18B20 Abstract 　　RS 485 bus due to the sending and receiving balance way to difference of common mode rejection capability is strong, high sensitivity, the transmission distance, the characteristics of high transmission rate in remote communication, remote measurement has been widely used, especially in the control field, will all kinds of control information through the RS 485 bus realizing remote monitoring and control. 　　This paper mainly introduces the single-chip microcomputer and computer through the RS 485 serial bus for remote communication measurement system design, including a PC as host data processing and multi-AT82S52 single chip microcomputer as from real-time temperature measurement machine, from the machine is the temperature sensor DS18B20 AT89S52 MCM and form a simple and practical real-time temperature measurement system, from the machine may conduct independent measurement, and the temperature of the real time measurement information through a 485 bus interface of the MAX485 chips will data to the host PC machine processing, in order to realize the remote real-time monitor and data transmitted over a long distance. The whole system design is simple, flexible and convenient use, the price is low, and can output the digital quantity directly, therefore has the very strong practicability. 　　 Keywords: Remote measurement; RS-485; MCU; Asynchronous communication;DS18B20 　 目录 摘要 i Abstract ii 第一章 绪论 1 1.1 选题背景 1 1.2 选题意义 1 第二章 系统设计的整体规划 3 2.1 RS-485系统设计的要求 3 2.2系统主要技术参数 3 2.3系统方案的确定 4 2.3.1温度传感器的选择 4 2.3.2 单片机控制器的选择 6 2.3.