Development Of Fieldbus Technology

Through worked quite well the traditional DCS system still have some weakness:First, the communication between the instrument and the control station of the DCS using analog signal and it may be easily disturbed. Second, all kinds of DCS systems are closed to each other for every manufacturer has their own system architecture. They can interchange the components between them, neither the control soft-ware. The 3rd weakness is that all of its control functions are centralized in the control stations and is regarded to be dangerous. That the Fieldbus Control System (FCS) based on FF is replacing the Distributed Control System (DCS) is irreversible. Being a e facto?industry standard of intelligent instruments, the HART protocols have its special superiority and practical value.One of the key problems of developing FCS is research and development of FF protocol, which is the purpose of this thesis. Besides, the paper introduces the improvement of intelligent transmitter based on HART protocol.This thesis includes as following:Chapterl introduces the summary of Fieldbus, including the history of Fieldbus, the international standard of Fieldbus and the prospect of Fieldbus.The first part of HART protocol include chapter 2,3,4.Chapter 2 introduces the physical layer, data link layer and commands of the HART protocol.Chapter 3 describes the type 1151 intelligent transmitter, also analyses the problem of old transmitter. Chapter 4 introduces hardware and software design, and the reason of choosing CPU. Some key technical problem is also discussed in chapter 4.The second part of FF protocol include chapter 5,6,7.Chapter 5 include FF protocol stack and the Data Link Layer. The subprotocol is analyzed and the whole development solution is presented here.Chapter 6 introduces the Application sublayer, which converts the information format between the user and the lower protocol layer.Chapter 7 include the Network Management and System Management sublayer, which is the unique part of FF and whose functions and implement are provided.Finally,We expect the development of FieldBus.