Research On Remote Monitoring And Maintenance Of Field Instruments Based On Ethernet

Information has been acquired from every corner of the world with the development of network and computer. In order to achieve long-distance and large-scale distributed measurement based on stereo vision, instruments are distributed in the complex and changefully field environment, remote monitoring and maintenance should be carefully designed and programmed for the reliable operation of the measurement instrument.In the context of the research and development of a coordinate measuring system of bomb-fall, this dissertation analyses remote monitoring and maintenance of field instruments based on Ethernet. The main contents and innovative points include:1. By analyzing the key techniques of remote monitoring and maintenance, a scheme to implement remote monitoring and maintenance of field instruments based on Ethernet is proposed. the embedded monitoring and maintenance terminals join up with Ethernet based on the collaborative work of MCU and NIC (Network Interface Chip),then the main contents of remote monitoring and maintenance programs of field instruments are elaborated.2. According to the remote monitoring and maintenance requirements of field instruments, actuating modules of remote monitoring and maintenance terminal are designed, these modules implement the functions of temperature and relative humidity monitoring, power voltage monitoring, remotely power on the embedded SBC and switch communication channels. The design of temperature and relative humidity acquisition using calibrated digital sensor and temperature control scheme are expatiated in detail, the heating and cooling device are designed based on semiconductor cooler, the temperature control experiment result is given.3. Ethernet communication interface of monitoring and maintenance terminal is designed, the hardware circuit and NIC driver design is given. The TCP/ IP protocol is condensed into the form of facing hardware and embedded into MCU, a reduced TCP state machine is given, the design of communication program based on embedded TCP/IP protocol is discussed in detail. At last, the communication ability of monitoring and maintenance terminal is tested and verified in virtue of the Sniffer Pro network analyzer.