Modbus Protocol-based Power Monitoring System

The real-time information of modern electrical networks have increased rapidly, the achievment of the unmanned substation and the remote control through the integrated automation control mode is a trend of substation management, and the communication protocol is the key to achieve control.Modbus protocol is a common language applied to the electronic controller, which is open, expansion, easy realization and wide range of users, so it's applied widely in the industry monitor and control field.This thesis discusses hardware and software designing and realization of a power monitoring system based onμC/OS-II, which transmits and receives data followed Modbus RTU communication protocol.On this basis the thesis have accomplished the function of remote communication with PC through the Modbus TCP.Firstly, the thesis introduces development and actuality of embedded system and substation monitoring system in a practical sense. Then, the thesis introduces some basic knowledge related to the work, including technical features of embedded systemμC/OS-II and Modbus communication protocol.In the last two chapters, the thesis narrate the design of hardware and software, some diagram and soft coding are presented.In software section, the thesis introduce portingμC/OS-II, then give a detailed description of the software design, and highlight the Modbus-based module of data acquisition and analysis.That system is a complete power control system, and has been deployed to the actual project.Practice has proved that this system is reliable, low-cost and high-expansionary. In order to provide remote monitoring and network management, based on the uIP protocol stack and RTL8019AS we expand system, and the communication with PC complies with the standard Modbus TCP protocol.Finally, we summarize the thesis, point out the deficient and what should be improved in the following work.