Research On Communication Protocol Of Building Automation And Control Network

The BACnet(Buliding Automation Control network)standard is the only ISO(International Organization for Standardization)standard in the field of intelligent building control.At present,the standard is mainly based on wired communication.How to efficiently transmit and control for different application scenarios is the core of intelligent building communication protocol research.This article is mainly based on the BACnet standard protocol,researches on a variety of typical scenarios,and designs different topology architectures and conducts simulation analysis.First of all,according to the needs of modern intelligent buildings,this article explains the domestic and foreign research progress of intelligent building system communication protocols.The article introduces the development of the BACnet standard and the data communication transmission technology used,discusses a variety of industrial real-time Ethernet buses,and analyzes the development status of wired transmission of intelligent buildings at home and abroad.Secondly,this article discusses the related technologies of BACnet communication network and protocol.The article first summarizes the BACnet standard,analyzes a variety of transmission technologies,clarifies the importance of studying wired communication,and then analyzes a variety of industrial Ethernet buses,including Ether CAT,PROFINET,Ethernet/IP,etc.,and points out them The existing advantages and disadvantages,and related comparisons between them.Then,this article analyzes the Ethernet communication protocol based on the BACnet standard,and discusses the application of the BACnet standard in wired scenarios.The application of the scenario is studied by designing linear network topologies,ring network topologies and tree network topologies.Finally,based on IEEE The 802.3 Ethernet transmission protocol has designed different topological network frame structures.Then,according to the two burst high-speed broadband transmission services of the linear topology network of the intelligent building,this paper designs a combination of static time slot and dynamic time slot allocation,and performs the performance of the two transmission services based on different data frame structures.analysis.Aiming at the frame synchronization timing deviation,this paper proposes a scheme to add a guard interval between nodes,and simulates and analyzes the data transmission error rate of the nodes.The simulation results show that the scheme can meet the needs of burst high-speed broadband transmission services under different data frame structures,and changing the dynamic time slot allocation can optimize the performance of the entire network.Finally,this paper studies and compares the non-linear topology networks of intelligent buildings.First,it explains the reasons for the network delay in the system,and then designs the frame structure of the ring topology network architecture and the tree topology network architecture.Then this paper calculates the minimum cycle time of different topology networks,and analyzes the delay and minimum cycle time of the topology network through Matlab simulation.It can be seen from the simulation results that the network performance of the ring topology is more stable when data is transmitted,while the advantage of the tree topology is that the adjustment ability of the system network is better than the ring topology,and the two nonlinear topologies are in different frames.The structure can meet the needs of transmission services.