摘要电力监控系统主要由三个层级结构构成，分别是：主控层、通信层和设备层，在该系统的作用下，电力系统中数据信息的分布式采集和集中式监管得以实现。本文基于Modbus TCP通信协议，对电力监控系统中的通信部分进行了设计。首先，研究了Modbus通信规约，比较了Modbus和Modbus TCP 之间的区别并研究了Modbus向Modbus TCP转换的原理和方法；其次，分析了RS485与RS232的优缺点，设计了RTU模式下基于RS485接口的Modbus TCP通信单元；最后，利用本文设计的Modbus TCP通信单元，在包括10台CRD-600监控装置的硬件平台上进行了模拟仿真测试。测试中，通信能够正常进行，可以实现数据的集中监控管理，系统的有效性和通信的正确性得到了验证。22295
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 基于Modbus TCP电力监控系统的设计与应用:http://www.youerw.com/zidonghua/lunwen_14855.html