ASHRAE 135-2024 ✓ Most Recent

BACnet, the ASHRAE building automation and control networking protocol, has been designed specifically to meet the communication needs of building automation and control systems for applications such as heating, ventilating, and air-conditioning control, lighting control, access control, and fire detection systems. The BACnet protocol provides mechanisms by which computerized equipment of arbitrary function may exchange information, regardless of the particular building service it performs. As a result, the BACnet protocol may be used by head-end computers, general-purpose direct digital controllers, and application specific or unitary controllers with equal effect.

This protocol provides a comprehensive set of messages for conveying encoded building automation data between devices:

• Hardware binary input and output values
• Hardware analog input and output values
• Software data values
• Schedule information
• Alarm and event information
• Trend and event logs
• Files
• Control logic
• Application specific data for a large range of building services
• Network configuration including security

The 2024 edition of Standard 135 includes many new capabilities and several clarifications. These new capabilities include a BACnet/SC Certificate Authority Requirements Interchange File Format, support for BACnet/SC configuration including certificate management, Device Proxying, Authentication and Authorization, new Color Object concepts and modernization of language used for defining to MS/TP.