基于RS485的远程采集与控制系统的设计毕业设计（论文） - 图文

南华大学船山学院毕业设计（论文）

基于RS485通信的远程采集与控制器设计

摘 要：在一些环境条件恶劣、异常危险的环境中，如深井、对人体危害极大强辐射空间、人体活动不便的空间，要做到现场数据综合分析并做出现场决策，几乎是不可能做到的。在这些环境中，远程数据采集与控制系统有着其巨大优势。还有一些管理分散，数据采集量大的工作条件下，人到现场去采集数据就变得非常繁琐了，这时，远程数据采集就是一种非常简单而且有效的方法。所以本文便提出一种基于RS485通信的远程数据采集与控制的方法。

本文设计的目的是实现3路数据采集处理，2路数据反馈装置，2路继电器控制远程控制。本文首先对涉及的RS485协议进行介绍，其次会给出远程数据采集与控制系统的硬件设计方案，硬件设计中包括单片机应用电路、电源稳压电路、AD采集电路、DA电路、RS485接口电路、继电器控制电路几个部分的硬件电路设计。最后给出切实可行的软件设计方案，在这个方案中会给出通信协议、整体设计与实现、系统的初始化、RS485总线程序、继电器控制程序、DA输出控制程序、AD采集程序的设计。本设计的的采集模块不局限某一单一用途，可以完成温度、湿度、压力、流量、位移、电压、电流等模拟量的采集。系统接口简单可靠，用途多样，具有一定灵活性。

关键词：RS485；远程通信；数据采集；远程控制

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南华大学船山学院毕业设计（论文）

Design of the Remote Acquisition and Controller

based on RS485 Communication

Abstract: In some poor and very dangerous conditions, such as deep well, strong radiation space which do harm to human beings and the space which is inconvenient for human's activities, it's almost impossible to make on-the-spot comprehensive data analysis and decisions. In these conditions, remote data acquisition and control system has its great advantage. In some other conditions whose management is decentralized and data collection is large, to make on-the-spot data acquisition becomes very complicated, so remote data acquisition is a good and convenient way.

This article will put forward a remote data acquisition and control method that is based on RS485 communication. Its purpose of the design is to realize three-channel data acquisition processing, two-channel data feedback device, two-channel way relay control remote control. First, this article will introduce the RS485 protocol. Then, this article will give the hardware design scheme of remote data acquisition and control system. The hardware design includes microcontroller application circuit, power supply voltage regulator circuit, AD sampling circuit and DA circuit, RS485 interface circuit and relay control circuit part of the hardware circuit design. Finally, practical software design scheme will be given.This design scheme includes the overall design and implementation, system initialization, RS485 bus, relay control, DA output control program, the AD acquisition program design. Collection module of this design is not limited, and not just for a single use, it can complete many collection, for example, temperature, humidity, pressure, flow, displacement, analog quantities voltage, and current .The system interface is simple and reliable, and its uses is various and flexible.

Keywords: RS485; remote communications; data acquisition and control

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南华大学船山学院毕业设计（论文）

目 录

1 绪 论.................................................................................................................... 1

1.1 研究的背景与意义.......................................................................................... 1 1.2 国内外研究现状.............................................................................................. 2 1.3 本文主要工作内容.......................................................................................... 3 1.4 系统分析.......................................................................................................... 4

1.4.1任务要求................................................................................................. 4 1.4.2 设计方案论证........................................................................................ 4 1.4.3 总体设计................................................................................................ 6 1.5 本文章节安排.................................................................................................. 7 2.1 RS-232/422/485 标准 ...................................................................................... 8

2.1.1 RS-232 标准 .......................................................................................... 9 2.1.2 RS-422/485 标准 ................................................................................... 9 2.2 RS-485 通讯协议 .......................................................................................... 12

2.2.1 ModBus 协议(RTU 模式) .................................................................. 12 2.2.2 多功能电能表通讯规约(DL/T645-1997) ........................................... 15 2.3 RS-485 应用要点 .......................................................................................... 16 2.4 本章小结........................................................................................................ 16 3 基于RS485通信远程采集与控制器的硬件设计 ................................................. 17

3.1 硬件系统总体设计........................................................................................ 17 3.2 单片机应用电路............................................................................................ 18 3.3 电源模块电路................................................................................................ 20 3.4 主从机RS485接口电路设计 ....................................................................... 21 3.5 继电器控制电路............................................................................................ 24 3.6 2路DA转换电路 .......................................................................................... 25

3.6.1 TLC5615简介 ...................................................................................... 25 3.6.2 TLC5615功能框图 .............................................................................. 25

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南华大学船山学院毕业设计（论文）

3.6.3 TLC5615引脚功能 .............................................................................. 26 3.6.4 TLC5615推荐工作条件 ...................................................................... 26 3.6.5 TLC5615的时序 .................................................................................. 27 3.6.6 TLC5615的两种工作方式 .................................................................. 27 3.6.7 DA电路 ................................................................................................ 28 3.7 3路AD转换电路 .......................................................................................... 28 3.8 本章小结........................................................................................................ 29 4 基于RS485通信远程采集与控制器的软件设计 ................................................. 30

4.1 通信协议的设计............................................................................................ 30 4.2 主程序流程.................................................................................................... 32

4.2.1 主机主程序流程.................................................................................. 32 4.2.2 从机主程序流程.................................................................................. 36 4.3系统初始化..................................................................................................... 41

4.3.1 主机系统初始化.................................................................................. 41 4.3.2 从机系统初始化.................................................................................. 43 4.4 RS485总线的程序设计 ................................................................................. 45 4.5 继电器控制程序的设计................................................................................ 46 4.6 2路DA输出控制程序设计 .......................................................................... 46 4.7 3路AD采集程序设计 .................................................................................. 47 4.8 本章小结........................................................................................................ 50 5 总结与展望.............................................................................................................. 51

5.1 总结................................................................................................................ 51 5.2 展望................................................................................................................ 51 谢 辞.......................................................................................................................... 53 参考文献...................................................................................................................... 54 附件一 电路原理图.................................................................................................... 56 附件二 PCB图 ........................................................................................................... 59

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