基于Modbus TCP电力监控系统的设计与应用
关键词：电力监控系统 Modbus TCP RS485 CRD-600
毕业论文设计说明书（论文）外文摘要
Title Design and Application of Modbus TCP.based Power Monitoring System
Abstract
Power monitoring system is mainly constituted of the three level. structures, namely: Master layer, communication layer and device layer. The distributed collection and centralized supervision of the power system data can be achieved in the system. In this paper, a power monitoring system is designed based on Modbus TCP communication protocol. Firstly, the Modbus communication protocol , the difference between Modbus and Modbus TCP and the methods of converting Modbus to Modbus TCP have been studied; Then, the advantages and disadvantages of RS485 and RS232 are analyzed and the Modbus TCP communication unit based on the RS485 is designed under RTU mode; Finally, using the Modbus TCP communication unit designed in this paper , power monitoring system is simulated on the hardware platform which is constituted of 10 CRD-600 monitoring devices. In the test, the communication can be realized normally and centralized monitoring and management of data can be realized. The feasibility of the system and the correctness of the communication have been verified.
Keywords Power monitoring system Modbus TCP RS485 CRD-600
目次
1 绪论 1
1.1 电力监控系统的作用及发展状态 1
1.2 现场总线 2
1.3 Modbus的总体描述和应用 2
1.4 小结 4
2 Modbus 通信协议 5
2.1 Modbus数据单元 5
2.2 Modbus标准功能码 6
2.3 Modbus通信原理 8
2.4 串行链路上的Modbus协议 9
2.5 Modbus传输模式 10
2.6 小结 11
3 Modbus TCP 12
3.1 Modbus TCP协议总体通信结构 12
3.2 Modbus TCP数据帧及MBAP报文头 12
3.3 Modbus TCP的客户机/服务器模型 13
3.4 Modbus TCP响应处理 14
3.5 Modbus TCP通信协议的通信描述 16
3.6 小结 17
4 通信接口与系统整体设计 18
4.1 RS232与RS485 18
4.2 RS485通信的特点 18
4.3 网络时间考虑 19
4.4 系统网络结构 19
4.5 系统通信信息点设定 20
4.6小结 23
5 软件设计 24
5.1 通信流程 24
5.2 数据类型定义 25