Studies And Developments Of Bus-Powered Technology On Industrial Ethernet

With the quickly development of Ethernet technology, the uncertainty of data transmission of Ethernet has been resolved gradually. So it becomes an irresistible tendency that Ethernet technology will extend the use to industrial field equipment level beyond traditional management level. Now domestic and international companies are both at the start stage in the research of industrial Ethernet. And this offers us a chance to compete fairly with international companies to formulate the new standard.Under the support of 863 Program, the author's laboratory, the national laboratory of industrial, has undertaken lots of works and drafted out an industrial Ethernet standard called EPA for short after tackling the key problems in the area of industrial Ethernet.As a sub-project of EPA, the main task of this project is to research a bus-powered method on industrial Ethernet, and prove the correctness and feasibility of the method by designing a system prototype. In the beginning, the paper analyses and compares several technologies in control industry and gets the result of the necessity and advantage of bus-powered technology. After a deeply researching of the power over Ethernet technology, a bus-powered method on industrial Ethernet is given in the paper. Then, the intrinsic safety which will influence the design of power system is discussed; it includes the principle and methods to protect the instruments for explosive atmosphere, and the recent development of the intrinsic safety of Ethernet. Further more, pre-detection module and power-management module which has the capabilities of detection, classification and power-off protection are designed by using chip microcomputer technology. Using these two modules, a power system prototype is built and a satisfying result is showed by the test of the system prototype. At last, the whole work and prospects of the later work are summarized in the paper.In this paper, the power souring equipment of the designed system prototype has well performed the detection and classification functions to the powered device. It is a creative attempt by using a safety mechanism in the research of bus-powered technology on industrial Ethernet, and it resolves the problem of the validation between the power souring equipment and the powered device before powering on. With the development of the intrinsic safety technology of industrial Ethernet, the problem of bus-powered will be resolved finally and pave the way for Ethernet technology into the industry field equipment level.