Design Of Electrical Meter-Reading System Based On GPRS

With the development of economy and society, electric power is getting more and more importance in our daily life. How to read the electric meter by long-distance and manage this system properly has been the focus of electricity field. At the same time, using the GPRS technology which has been mature in computer and communication domain into the power meter-reading system is now becoming high-light in electric industry. This dissertation focuses on power meter-reading system based on the GPRS. This system uses GPRS technology to monitor and manage the power usage by long-distance. The whole system consists of main station software and hardware terminals. The main station software remote control the users' terminals, editing and distributing the collecting or load plan, receiving the alert data of the terminals. Installed in scene, the hardware terminals collects, monitors and manage the users' power meters at real time followed by the commands of main station software. The terminals use embodied platform design. This study mainly discusses the design and implementation of the GPRS-based power meter-reading system, especially focuses on main station software and terminal software.In the practical use of GPRS-based meter-reading, terminals get on the internet by GPRS, their IP are achieved dynamically and change ceaselessly. Meanwhile the client has intranet IP distributed dynamically. Then the communication between these two dynamic IP is a technical problem. By analyzing client requirements adequately, this dissertation creates a practical project to resolve this problem. In this project, the main station is designed with four systems: communication server; front-end server; application server; client program.Settled on the Internet, communication server has static IP. It supplies the transfer serve for electricity bureau intranet to visit the GRPS terminals, receive the data which the terminals upload and distribute the command which the main station give off to the specific terminal. In essence, the communication server is a communication proxy between client and terminal.As the communication media between client and communication server, the front-end server supply the functions such as command queue; data cache; communication encapsulation; failure monitor, etc. It can also act as a communication proxy between client and communication server, fulfilling the commands of client and receiving the results.Application server system has two functions. One is web distribution, offering the clients WEB query, statistic and analyze functions. It can also supply other models Web Service. The other function of this system is to be an application server, encapsulating the data and part of the logic functions, easing the client operation, improving the safety of database visiting.Client faces the users directly, supplying many functions, such as terminal management, real time data collection, etc.There are so many domestic terminal producing companies. Almost everyone has its own communication protocol. A main station system must be compatible so as to apply different terminals. But how to turn this design into reality, It's a practical problem we must solve. This study put forward a creative program project based on the abstract terminal. This project collects all the commands from different terminals, transforming them into a set of virtue commands. The whole system does not transform the virtue commands into physical commands until the front-end server distribute the commands. Using this project, different terminals communication library can be used by the higher layer as components. To add a new terminal, just supply the front-end system a new communication DLL library.The system this dissertation discusses is designed strictly by three-layer architecture: presentation layer; business logical layer; data access layer. These three layers are designed separately, running on different computers in distributing mode, calling the component and communicating by Remoting and Web Service. This architecture implements the encapsulation and isolation for the data, improving the safety of the database servers.The main function of GPRS-based meter-reading terminal software system is to receive the commands of the main station, to monitor the power meter and some other equipment at real time according to the program of main station, to save and upload the data. The specific functions include timing collection; real time collection; alarm monitor. The terminal program support several communication ways such as infrared, GPRS and serial port. Memories of ATM platform are small, reading and writing speed is low, but it need save a great number data. To solving this problem, the dissertation put forward a dynamic save project to improve the save speed and advance the efficiency of the system. Flash reading degree is limited but this project design a simple bad block dynamic program to solve this problem.This dissertation discusses particularly the communication server, front-end system, application server and terminal program, draw an outline of the client and WEB presentation. Beside these, the study resolves some practical problems such as real time communication, a lot of terminals running at the same time, etc. At the end of this dissertation, it discusses the application of popular software technologies (for example: design pattern; Web Service and Remoting) in GPRS-based power meter-reading system.