The Research And Design Of LonWorks Intelligent Node

Fieldbus is a brand new network integrating automatic control technology, which is based on the open systems interconnection model. It has many advanced characteristics such as full digital communication, intelligent field devices, completely distributed structure and open interconnect protocol. Fieldbus can change the traditional automation from isolating information system to distributed, intelligent control network. LON is a Local Operating Networks put forward by American Echelon Corporation in 1991, offers a powerful means for distributed control. For supporting the LON, Echelon Corporation designs a suit of platform, that is called LonWorks technology.First, this paper discusses basic concept of fieldbus. After introducing the basic theory of fieldbus, background of putting forward the task and the author's main works, it reviews briefly the develop course of the fieldbus, introduces the advanced character of fieldbus and puts forward the prospect of the fieldbus development. This paper detailedly dissertates the technology content of LON. In conformity to designing the intelligent node, It introduces the core technology of LonWorks, including Neuron Chip, firmware of Neuron Chip, software system of Neuron C, usual LonWorks development tools, discusses the theories of interoperability and the methods of realizing the interoperability by Echelon Corporation, and dissertates hot points of LON fieldbus nowadays.According to the introduction of basic theory, this paper put forward a total design of the intelligent node including hardware and software realizations based on LonWorks technology. It dissertates detailedly the design method of functional circuit of intelligent node with temperature as the object, includes the Control Module, data acquisition, display, power and so on, and points out the advertent problems in the progress of designing the circuit. According to the design of hardware, it sets forth the design methods of Neuron C application software of intelligent node accord with the LonMark Standard with examples of data acquisition and seven segment code display, and dissertates resolvment of the watch and control software in the top layer based on the LNS DDE Server.According to building automation system, whose function is complete and which leads in technology and is first in China, This paper introduces the application of LonWorks intelligent node in brings forward the project, detailedly discusses the structure, composing and the methods to realize various functions with intelligent nodes.In the end, the author summarizes this paper, and sums up technique fruit and engineering experience from the project.