Research On Automatic Meter Reading System With GPRS

Automatic Meter Reading (AMR) is a new technology in the supply and management of water, power, and gas. The disadvantage of traditional manual meter reading system can be overcome, such as lower efficiency and so on. Meanwhile, with the development of General Packet Radio Service (GPRS) technology, which is introduced into the AMR system is a new idea and will become a trend.In this paper, a new automatic meter reading system based on GPRS is presented. The system is based on the analysis of AMR technology and to meet the application of GPRS in wireless data transfer system. The lower layer is adopt RS-485 bus topology, upper layer utilizes direct connection between GPRS and Internet, setting a center server in Internet to take charge of data communication with GPRS terminal equipment for real-time data acquisition and transfer.The hardware and software design of data terminal equipment with GPRS is researched in this paper, which is the key technology of the system. The hardware design of data terminal equipment is interface and supporting circuit design of the micro-controller and GPRS module. MSP430F149 is selected as the MCU of this platform, Siemens MC39i lead-free module is chosen as the GPRS module. The equipment is compact,reliable and steady. As to the software project, firstly, many international protocols of GPRS are researched and the reduced TCP/IP protocol of this system is proposed. Secondly, Point-to point protocol is researched and reduced PPP programming scheme is given. Thirdly, compared the transmission layer protocol UDP with TCP in the transport efficiency and system requirement, for the single chip system, UDP is preferred in our system. Lastly, the user-defined protocol in application layer is proposed, by adding the number byte in data frame and adopting the scheme of response to assure the reliability in data transmission.The AMR system proposed in this paper can be used in power meter system and other wireless transfer applications. It can find wide applications and acquire great economic and social benefits.