BACnet

BACnet
Name	BACnet
Developer	ASHRAE
Initial release	1995
Latest release	ISO 16484-5 amendments
Written in	C, Embedded C, C++
Operating system	FreeRTOS, Linux, Windows, RTOS variants
Genre	Building automation protocol

BACnet

BACnet is a communications protocol for building automation and control, designed to allow devices from multiple manufacturers to interoperate across HVAC, lighting, access control, and fire detection systems. It provides standardized object types, services, and network layers to support system integration in commercial, institutional, and industrial facilities. BACnet is governed by standards bodies and widely adopted across vendors and projects worldwide.

Overview

BACnet was developed to address integration challenges among vendors such as Siemens, Johnson Controls International, Schneider Electric, Honeywell, and Siemens AG subsidiaries, enabling connectivity among devices in projects like the Burj Khalifa, Wembley Stadium, and corporate campuses of companies such as Google, Amazon (company), and Microsoft. The protocol is standardized by organizations including ASHRAE, ISO/IEC, and adopted in building codes and procurement standards used by institutions like U.S. General Services Administration, National Institute of Standards and Technology, and multinational consortia such as CIBSE. Major integrators—examples include Siemens Building Technologies AG, ABB, Schindler Group, and Carrier Global Corporation—implement BACnet in controllers, gateways, and supervisory systems for facilities in cities like New York City, London, and Singapore.

History and Development

Work on BACnet began under the auspices of ASHRAE committees influenced by participants from Trane Technologies, Ingersoll Rand, and the American Society of Heating, Refrigerating and Air-Conditioning Engineers membership. Early demonstrations involved vendors showcased at trade shows such as AHR Expo and conferences like Realcomm and LightFair International. The standard evolved through ballot cycles, amendments, and collaborations with ISO/IEC JTC 1 and regional standards bodies. Adoption accelerated with endorsements by building owners including General Motors and Walmart (company), and integration projects tied to construction firms like Bechtel and Skanska.

Protocol Architecture and Components

BACnet defines services—such as Who-Is, I-Am, Read-Property, and Write-Property—and object types including Analog Input, Analog Output, Binary Input, and Calendar. Vendors like Honeywell International Inc. and Johnson Controls implement these services in controllers and supervisory panels, integrating with building management systems from Schneider Electric SE and Delta Electronics, Inc.. The architecture maps to networking models used by standards organizations including IEEE and IETF for lower-layer interoperability, and coordinates with protocols employed in projects by Cisco Systems, Inc., Oracle Corporation implementations, and embedded platforms from ARM Holdings.

Communication Media and Networking

BACnet supports multiple transport options including Ethernet, IP, MSTP (RS-485), ARCNET, and point-to-point serial, enabling deployment across infrastructures managed by firms like AT&T, Verizon Communications, and fiber backbones used by Equinix. Implementations often run over IPv4 and IPv6 stacks standardized by IETF working groups, and interoperate with network equipment from Cisco Systems, Juniper Networks, and industrial Ethernet providers such as Belden Inc. and Molex LLC. Large-scale projects in airports—e.g., Heathrow Airport and Hartsfield–Jackson Atlanta International Airport—use BACnet across zones coordinated with facility management services like Sodexo and CBRE Group.

Object and Data Modeling

Objects in BACnet encapsulate properties, alarms, and scheduling used by controllers made by Siemens Building Technologies AG, Johnson Controls International plc, and Schneider Electric. Integrators map these objects to supervisory applications from Siemens and open-source platforms such as projects inspired by Linux Foundation initiatives. Data modeling enables integration with analytics and tenant platforms developed by companies like IBM, Siemens Energy, and startups incubated in accelerators like Y Combinator for energy optimization and fault detection in buildings owned by entities such as The Walt Disney Company and IKEA.

Interoperability, Security, and Standardization

Interoperability testing events—hosted by organizations like BACnet International and supported by labs at universities such as Massachusetts Institute of Technology, Georgia Institute of Technology, and ETH Zurich—ensure multi-vendor compatibility. Security considerations have been addressed through addenda and secure variants integrating cryptographic practices from standards bodies including NIST and IETF TLS/DTLS, with products audited by firms like Deloitte and KPMG. Compliance and certification programs reference building codes and procurement rules influenced by agencies such as European Committee for Standardization and regulatory frameworks in jurisdictions including California, New York (state), and the European Union.

Implementations and Applications

BACnet is implemented in controllers, supervisory software, and gateways by manufacturers such as Schneider Electric SE, Honeywell International Inc., Johnson Controls International plc, Siemens, and Delta Electronics, Inc.. Applications include HVAC control in landmarks like The Shard, lighting control in cultural venues such as the Sydney Opera House, and integrated safety systems in hospitals managed by networks like Mayo Clinic and Cleveland Clinic. BACnet interfaces with energy management platforms from Schneider Electric and Siemens Energy and participates in smart-building deployments coordinated with urban initiatives from municipalities including Singapore and Barcelona.

Category:Building automation