Research Of The BACnet Building Controller Based On ARM9 And Embedded Linux

With the continued development of information technology, people on the requirements of the building environment have been improving. It promotes the rapid development of the intelligent building and building automation systems. An important part of building automation systems-building control communication network is going through that is form companys designing their own communication protocol to the unified and open communication protocol. BACnet standard is the only building control network data communication protocol with international standards, It is gradually being accepted and used by the building control equipment manufacturers.BACnet standard be depth studied in this thesis. Combined the actual situation which is within a building general layout of the Ethernet, there applied BACnet/IP technology and designed an building controller. The building control center can link this controller that is in different floors and have different function, in high-speed Ethernet.The main contents in this thesis is showed in follows:First, according to the BACnet standard, the thesis depth understanding of the BACnet protocol architecture, object model, service model, coding rules, principles, and the principle of building control systems. On this basis, it designed the model of BACnet controller and choiced the specific hardware platform and software platform for the controller.Second, through investigation and study, the thesis used the ARM9 embedded processor as the core of hardware platform and designed the peripheral and auxiliary circuit of processor. According to the specific needs of the controller, it designed the storage system, the Ethernet interface circuit and the controller input and output modules of the functional circuit.Third, the thesis described the embedded operating system migration. Embedded operating system software provided a stable environment for the system and maked that the application has good portability. This thesis used an embedded Linux operating system. The operating system migration inclued in the BOOT LOADER migration, kernel migration, file system migration and driver migration.Finally, it was the design of the controller application, which focused on the completion of the BACnet protocol stack specific C language. The service data of application transformed to TCP/IP data packets through the tag coding, the coding of application layer, and the coding of the network layer. The thesis designed the control programs, control algorithms and the method which is the controller integrated in engineering application.