Research On Centralized-Monitoring System Of Middle Water Recycling

As the resources of water is contaminated increasingly and seriously, monitoring for water quality become more and more important. Because the customers using water is scattered about and the quantity is large .It become a very serious problem to implement real-time water quality monitoring efficiently and reliably.Currently, the main method of middle water-quality monitoring mostly is the distributed intelligence network which is based on the LonWork net domestically and internationally .In this method, the node is used which is composed of Neuro chip(nerve cell chip) as the monitor terminal controller. The local monitor terminal was connected to the LAN through the host computer,so as to realize centralized monitoring. Although this kind of monitoring system could present real-time watching of the testing data, the disadvantage was the high cost of the net and small area of monitoring. The other method was a centralized one which was based on Internet, but the fee spended on the monitoring data tranfering through Internet was high.According to the actual characteristic of water-quality testing spot,In this paper, a new scheme of water-quality centralized monitoring is put forward which is based on wireless SMS(Short Message Service)—that is –use the GSM SMS data tranfer platform as the transmission channel between the local monitoring station and the monitoring center.In this paper, the GSM wireless communication net was deeply studied, the principle and technology of the interface between the GSM wireless transceiver and the local host was also deeply researched. The interface circuit and the serial communication program was given.It was proved that this system could realizd the long distance monitoring data transmission wirelessly.This system introduce PLC to implement the acquisition and storage of the COD value of the water-quality monitoring terminal.The testing data was transferred to the host through the asynchronism serial COM.This paper go deep into the asynchronism serial communication interface between the PLC and the host PC, both the interface circuit and communication program was also designed. They could implement the asynchronism serial data commuication between PLC and the host by simulating. An on-line COD value monitoring scheme was proposed and trailed and developed.In this paper, the monitoring system make full use of the existing communication infrastructure,large area water-quality monitoring was carried out. Because of the low service fee of the GSM SMS,this system was of low cost,and that monitoring middle water-quality of large area with low cost was come true.This system was provided with such advantages as the little investment,the convenience of usage,the large scope of supervising and controlling and the low expenses when circulating etc.It will promote to implement the national policies of water-resources-protecting.It will have the profound and actual meaning.