The Research And Design Of Monitoring Network Based On Modbus/TCP

With the rapid development of social economy and cities, the quality of city atmosphere is becoming more and more serious. It is of great value to establish an air monitoring system which is high-quality and high-efficiency in order to heighten the quality of air and improve the environment of atmosphere. This thesis does an analysis and design work on the air quality monitoring system mainly. The contents and fruits of this research are as bellow:First, the concept of industrial Ethernet was introduced, then its history, current status and development in the future were analyzed, especially the protocol of Modbus/TCP. The design idea of establish a network communication system based on the Modbus/TCP was presented. Second, through the analysis of function requirements of air quality monitoring network, the thesis put forward the idea of design master system make use of Kingview which is mighty-function, steady-performance, expedite-operation. In the slave system, native database storage module, Modbus/TCP data processing module and exception handles module were designed in use of modularization idea. The communication protocol between master system and slave system is Modbus/TCP. In order to make the communication data reliable, the double communication channels: ADSL/GPRS were used. Third, through deep analysis of Modbus/TCP protocol, based on WinSock module and multi-thread technology, the Client/Server communication mode is presented. According to the network structure of multi-slave and single-master, a kind of data format is defined and it guarantees integrity to transmit data. In the end, in virtue of advanced computer technology and communication technology, using multi-layer systematic, a air quality monitoring system that integrates intelligence, network and systematization is constituted.The system has been successfully implemented the primal requirement and shown huge superiority in reliability, real-time, security. In the course of running and debugging the system, all the functions satisfy the demand of application.