What is the role of the field bus/network in a BAS?

• A. Connect devices and transport data between field devices and controllers
• B. Supply air to zones
• C. Control lighting fixtures
• D. Manage energy tariffs

Answer: (A)

The field bus/network is the communications backbone of a BAS. It interconnects sensors, actuators, and controllers, carrying the data they generate and the commands that control equipment. For example, a temperature sensor sends its reading to a controller, and the controller sends a damper position command back to an actuator to adjust airflow. This shared data path reduces the need for point-to-point wiring and enables scalable, real-time control and monitoring across the system. While supplying air, controlling lighting, or managing energy tariffs are important functions in a building, the primary role of the field bus is to enable reliable data exchange and command transmission between field devices and controllers.