What is BACnet? Everything you need to know

October 9, 2023

BACnet, standing for Building Automation and Control Network, is a global standard for data communication in building automation and control systems. This article endeavors to answer fundamental questions about BACnet and its aim to enhance building efficiency and foster a global community of building automation enthusiasts.

Quick access:

What is BACnet?

What are the key features of the BACnet protocol?

Who developed BACnet?

What encoded data can BACnet convey?

Why is BACnet important for building automation?

How widely is BACnet used?

How does CIM utilise BACnet?

What type of data does PEAK collect via BACnet?

How does PEAK handle non-BACnet/IP compatible sites?

What is BACnet protocol?

BACnet is a data communication protocol designed specifically for managing and controlling building automation and control systems. These systems include heating, ventilation, and air conditioning (HVAC) systems, lighting, access control, fire detection systems, and other building management systems. Developed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), BACnet provides a standard method for the different systems in a building to communicate with each other, regardless of the manufacturer.
BACnet helps facility managers and building owners integrate and manage their building systems more efficiently, leading to reduced energy consumption, improved building performance, and enhanced occupant comfort.

What are the key features of the BACnet protocol?

The key features of the BACnet protocol include:

  • Interoperability: BACnet was designed to ensure that equipment from different manufacturers can work together in a single building management system.
  • Scalability: It can be used in both small and large installations, from a single building to complex campuses with multiple buildings.
  • Flexibility: BACnet supports various communication networks, including Ethernet, IP, MSTP (Master-Slave/Token-Passing), and wireless technologies, allowing it to be adapted to many different types of building environments and requirements.
  • Object-Oriented Approach: The protocol uses an object-oriented approach to represent different devices and functions within the building automation system, making it easier to implement and understand.
  • Standardization: As an ASHRAE, ANSI, and ISO standard (ISO 16484-5), BACnet ensures that devices conform to a globally recognized standard.

Who developed BACnet?

BACnet was developed by ASHRAE, the American Society of Heating, Refrigerating and Air-Conditioning Engineers. ASHRAE is an American professional association seeking to advance heating, ventilation, air conditioning and refrigeration systems design and construction. ASHRAE has over 50,000 members in more than 130 countries worldwide. The relevant standard can be found at: ASHRAE Standard 135-2016 - BACnet - A Data Communication Protocol for Building Automation and Control Network.

What encoded data can BACnet convey?

BACnet provides a comprehensive set of messages for conveying encoded binary, analog, and alphanumeric data between devices including, but not limited to:

  • Hardware binary input and output values
  • Hardware analog input and output values
  • Software binary and analog values
  • Text string values
  • Schedule information
  • Alarm and event information
  • Files
  • Control logic

It models each building automation and control computer as a collection of data structures called objects, the properties of which represent various aspects of the hardware, software, and operation of the device. These objects provide a means of identifying and accessing information without requiring knowledge of the details of the device's internal design or configuration.

Why is BACnet important for building automation?

BACnet's significance lies in its ability to foster interoperability among various building automation and control systems, irrespective of the vendor. This interoperability facilitates seamless communication and operation among different systems, thereby enhancing building efficiency, reducing operational costs, and ensuring a more sustainable building ecosystem.

How widely is BACnet used?

BACnet holds a notable market share in building automation and control systems. A study indicates that BACnet's global market share has continued to rise over the years, exceeding 60%​​. The market for BACnet Building Management Systems is anticipated to grow further, emphasizing the protocol's significance in this sector​​.

How does CIM utilise BACnet for data collection?

CIM's building analytics software, the PEAK Platform, integrates with building control systems and sensors, where BACnet plays a crucial role. To ensure compatibility, CIM requires the Building Management Systems (BMS) to be BACnet/IP compatible or support automated CSV exports. Data collection is achieved via a plug-and-play gateway device named 'BACER,' which is installed on the building's Building Automation Control (BAC) network. This device continually collects data from controllers, even during outbound internet disruptions, and sends it to the PEAK Platform for analysis and further utilisation.

What type of data does PEAK collect via BACnet?

Through BACnet, CIM's PEAK Platform collects data from Building Management Systems (BMS) like HVAC, lighting, indoor air quality, and sub-metering. Additionally, it can integrate data from third-party providers and APIs, such as utility metering and weather stations.

How does PEAK handle non-BACnet/IP compatible sites?

For sites that are not BACnet/IP compatible, CIM's PEAK Platform can ingest data via automated CSV extractions, facilitated through email from the BMS/EMS Server. This setup can be executed by a BMS/EMS technician, ensuring a smooth data acquisition process despite the lack of BACnet/IP compatibility.

Antonious Mickaeal
October 9, 2023
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