Study And Implementation Of GPRS Wireless Date Terminals In A Monitoring System

GPRS wireless network has been linked with the Internet and become a resource of sustainable used and developed. As GPRS network with strong real-time, low capital costs, large system capacity, high data transfer rate, and low cost of communications, GPRS communications applied to monitoring system has great significance. Because of low consumption and strong performance characteristics, the embedded system is widely used in telecommunications, industrial control and other areas. This thesis has studying on GPRS wireless monitoring system, built a monitoring system, used the embedded systems and the GPRS network, designed and implemented the GPRS wireless data terminals in a monitoring system.The terminal took the AT91SAM7A3 microprocessor as the center, with driving GPRS module of communication, connected to the Internet by GPRS wireless network, achieved data transmission in a monitoring system.Firstly the thesis introduced characteristic and principle of GPRS network, Constructed a monitoring system included user terminals, GPRS data terminals, transmission networks (GPRS networks and public data network), remote control central, then leads to key issues: the realization of GPRS wireless data terminals. Elaborated the function and application of GPRS wireless data terminal, followed by hardware and software design and realization of GPRS terminal. This terminal's hardware design mainly includes the choice of microprocessor chip, the interface design of M23 module of communication, the circuit design of memory modules and serial port and so on. The Software mainly includes the transplant ofμC/OS-Ⅱ on AT91SAM7A3, the realization of TCP/IP stack which including PPP,IP,UDP and so on. The division of system task and the specific realization of each function module. The software plan adopted can be described as an embedded operating system+TCP/IP stack+application program. The application program was developed on the basis ofμC/OS-Ⅱand divided into mufti-task, which simplified the software design of application system and improved the reliability of system. Then thesis designed and realization of remote data centers's software in the monitoring system, and the functions of GPRS data terminals were tested. Finally, the thesis summarized the work and puts forward improvement method and prospects.The GPRS wireless data terminal has realized in this topic, embedded in TCP/IP stack, can connect to the Internet through GPRS network, and real-time data transmission is strong, which provides the transparent data-transmission channel for users and have a wide range of applications in the power automation, environmental protection, transportation monitoring and other areas, particularly applicable to the mobile environment, wireless sites and remote areas.