Research And Realization Of The Campus Control Network Based On LonWorks Fieldbus

With the expansion of the campus scale and the prevalence of network, higher demands have been put forward for timely policy-making and information sharing. Since stolen cases occurred frequently on campus during the past years, the school leaders require that, during the campus network reconstruction, campus control system, especially the safety precautionary system, should be added to " digital campus " so as to guard against the fire, give out an alarm in case of fire, get the electricity power controlled, actualize security personnel supervising, automate water-supply-derange advices, automatically control buildings, etc.As an indispensable part of "digital campus ", the campus control system has adopted B/S structure as a whole, which is divided into three levels, including the campus worksite, scene and the Web server. Making the RDBMS which is based on B/S structure as the information integration platform, the campus control level realizes the distributed processing of information.. Scene level system accomplishes independent controlling process that is available for analyzing, accounting and managing of real-time datum by the system. At the same time, the system issues controlling order timely. The scattered intellectual nodes on the scene and the server platform have formed a B/S structure.In the distributed controlling system that is based on LonWorks bus, each on-the-spot intelligent instrument will be replaced by intellectual node that integrates the incorporating control, communication and I/O as a whole. Not only can the intellectual node accomplish the tasks of gathering and processing data on its own, but also transmit data to the computer in the controlling centre by communication node, so as to make the computer show, type the on-the-spot data , keep it in the archives or do other processing to it. At the same time the computer can send various orders to the intellectual node, so as to realize the real "digitalized" central management, optimized control and scheduling.In the direct numerical control system of the computer, PID controller is realized by the PID controlling algorithm procedure. Load PID controlling algorithm and other advanced algorithms written in Neuron C directly into intellectual nodes, and build up intellectual control algorithm or optimized algorithm on monitoring node In this way, most application demands can be satisfied, and the problem of memory capacity can also be solved . It not only maximizes the intelligence of the network, but meets the need of low cost and opening policy.The system has adopted the modular designing with its flexible structure, which is convenient both to be imbedded in another controlling system and to be expanded or upgraded to the more complicated and opened network, so as to realize the total networked process control.Try out LonWorks technology for controlling in the"digitized campus", and then expand it to all continuous, dispersed industrial fields such as electricity, metallurgy, petroleum, chemical industry, building materials, light industry, papermaking, commercial automation, automation of the buildings, traffic automation and home automation, etc. The mixing of on-the-spot technology and exiting network technology has very profound significance.