BACnet

BACnet is the global data communications protocol standard for building automation and control networks. BACnet was developed and is continuously maintained and enhanced by the BACnet Committee, a standing technical committee (SSPC 135) of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). BACnet is an ISO standard (EN ISO 16484-5), a European standard and a national standard in many countries.
BACnet provides a vendor-independent networking solution to enable Interoperability among equipment and control devices for a wide range of building automation applications. It was designed specifically to meet the communication needs of building automation and control systems. It includes specific support for building automation applications such as heating, ventilating, air-conditioning, lighting, access control, elevators, security and fire detection systems. BACnet enables interoperability among these systems by defining communications messages, formats and rules for exchanging data, commands, and status information. BACnet provides the data communications infrastructure for intelligent buildings and is a key component of smart cities.
A global product certification process is in place to ensure products claiming conformance to the BACnet standard have been independently tested using industry accepted test definitions. A global listing of products that have achieved certification is maintained by the BACnet Testing Laboratories (BTL).