Lntelligent Building Control Syetem Base On ARM Modbus Protocol

With the rapid development of science and technology and economy, the intelligentbuilding is used more and more widely at home and abroad now. Not only it has broughtthe facilitation enjoyment to the intelligent building occupants, but also brings convenientto the building manager. In contrast to the Complex and tedious traditional buildingmanagement, the modern intelligent building is toward to the development direction ofintelligent, integrated and opening up to society.In the current market, the intelligent building control products are mostly developingbased on the foreign products, but it brings a problem that if the key compent has problem,it is very trouble to solve. For example the Schneider’s building control system which isusing the LONWorks bus and including the OSI seven layer communication protocolmodel. The protocol is not open to the public and can only compatible with the same typeof products, so it can not be extended very good. if there is a problem, it is difficult torepair. The paper put the Modbus protocol as the data communication format, which isbelonging to the seventh layer application layer of the OSI model and can be used indifferent types of bus and network with good good compatibility and maintainability. Thehardware system is developed and designed based on the ARM processor platform with ahigher data processing capacity, high performance and high stability.The Direct Digital Control system in the paper mainly includes two parts which arethe DDC bus controller and the DDC controller. The DDC bus controller is mainlyresponsiable for the data processing and communicating with the upper monitor by modbusprotocol, and transimitting the data obtained from the DDC controller to the softwaresystem or transimitting the specified equipment movement data to the DDC controller.Connecting the DDC controller to the device sensor or the actuator directly, we can trackthe realtime state of the device through the analog input channel or the digital inputchannel, also we can control the device through the analog output channel or the digitaloutput channel.