The full form of BACnet is Building Automation and Control Networks. It was developed in 1987 with the backing of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. An American national standard. It is also a European standard and a national standard in more than 30 countries and also a part of an ISO global standard.
A data communication protocol that is mainly used in the building automation and HVAC (Heating Ventilation and Air-Conditioning) industry.
Equipment such as air conditioning machines, pumps, and ventilation devices are allowed to communicate with such protocol to be with a PLC. A high degree of automation is created with intelligent houses.
Source:- BACNet