The Research On HBS Fieldbus Technology Of Multi-Air Conditioner

With the high-tech engineering applications standing for information technology, which included the modern network technology, electronics technology, computer technology, software technology and so on, the future direction of building development, must be the intelligent building which integrated automation systems, office automation systems and communication automation systems. One building automation system is based on the building which combined with electricity and plumbing operations and services carried out in a wide range of system integration. Administrators can monitor and manage the various subsystems of intelligent building through the system management software.Currently, multi-air conditioners have been widely used in the apartment, houses and villas. It is free to carry out the identification and communication of the multiple indoor units and outdoor units, to achieve flexible control of all air-conditioned area. You can set different indoor ambient temperatures, according to the change of load and individual need. You can achieve the communications between the air conditioner and computer by HARC. You can easily detect and manage the operation of the air-conditioner through the management software on the computer. In short, the above characteristics also make the multi-air conditioners develop rapidly in the domestic market.To multi-air conditioners, one of the most important technologys is the realization of the communication, and it's different from the short distance and one-to-one mode between the indoor unit and the outdoor unit. Longer transmission distance, multi transmissions among multi equipments, self-identification of multi equipments, realizing the connection and data transmission with the software, all of these must be considered.In this thesis, after understanding actuality and development trend of the international fieldbus technology, the communication problems of the multi-air conditioner system are analysed, by comparing the characteristics of Fieldbus technology,MM1192 based on HBS communication protocol is finally selected as adapter chip. Around the chip, simplifying the system interconnection (OSI) seven layer model is simplified and the technical features of the physical layer, data link layer and network layer are cited.In this thesis, the design of electrocircuits to the physical layer is expatiated detailedly in the hardware design chapter,We detailed analysis of the chip and the external circuit, and the resolvent of the key problem is expounded:the selection and design of components, ways and means how to match impedance correctly to solve the problems such as Bit Error Rate and shortening of communication distance caused by ill-matched impedance, the methods how to carry out the software and hardware simulation on the singlechip without clock output are discussed.The design of the frame structure in data communication is the most important task of data link layer. The definitions of the main and assistant parts in control tactics are introduced according to the definitions of the baud rate and the bit constitute. The rule of address identification and data re-sending for the identification of the multi-devices in the same system is a perfect solution in the similar products. Data structure and the whole communication process are introduced briefly.The major software functions and software processes are also introduced.With the development of the network, it's indubitable that it's a good method using Web browser as the the system management software. In the thesis, the technology using the Web to realize the management is described brieflly. Air conditioning is a subsystem in the automation system integration, The development of air-condition centralized control and management through the centralized controller is introduced. At the same time, the methods how to connect the field bus is introduced.As one of the core technologies, The realization of the technology has solved the key problem which puzzles the development of corporations.Now the extension and application in our corporation are in the works.