Beijing Capital International Airport, Building Automation Protocol Conversions

With the rapid development of modern information technology, information technology businesses work more and more attention. In the large building construction and planning, the building control subsystems expanding the number and size of equipment and systems of non-uniformity between the protocol, making the management of the increasingly heavy, fieldserver makes the development of equipment and systems established a connection, so data conversion and call control even more of the specification, this paper on the Beijing airport in the HVAC air-conditioning project for development of the protocol conversion process, on the fieldserver functional requirements, performance requirements, data needs to be a detailed analysis, the use of software engineering in software development thinking on fieldserver protocol converter for Development. The focus of this paper is based on MODBUS, RS485 structure under study. MODBUS IDA is Johnson provided a standard protocol development platform for system developers to data transfer protocol provides a wealth of technology options. However, a high-quality application also depends on well-designed architecture support. How to apply MODUBUS core technology to design a stable, reusable MODUBUS application architecture is the problem to be solved in this paper. MODBUS technologies in various analysis and comparison, this paper models on the MODBUS layers depth research, the original 7 layer model into four layers, thus reducing packet length and reduce unnecessary processing overhead of communication It will also save the cost of production building automation industry; protocol defines its own network layer and application layer, which will control the system at a high level of unity. In the data link layer and physical layer, taking into account the fact that the existing established various networks, but also to make the agreement better compatibility, open, and taking into account the advantages and features of the standard, the agreement provides 5 different options, including Ethernet, ARCnet, MS / TP, RS485, RS232, LonTalk, etc.. Provided for each of the corresponding standards. Thus, fieldserver from architecture to ensure the standards and openness. Fieldser Gateway development is interoperability between different devices, called the agreement to enhance communications capabilities and to achieve the Beijing airport, HVAC automatic control systems of protocol conversion.