: Physical devices that interact with the building environment, including:

: Controllers and automation stations that process data and execute programmed logic for specific applications like air conditioning or lighting.

: High-level devices like operator stations, cloud servers, or management software for data analysis and human interaction.

A BACS typically functions through a modular structure consisting of three primary layers:

Building Automation and Control Systems (BACS) serve as the "brain" of a facility, integrating hardware, software, and services to monitor and manage utilities like HVAC, lighting, and security. This draft guide outlines the core components, standards, and implementation steps based on established industry frameworks like ISO 16484 and ASHRAE's BACnet . 1. Fundamental System Architecture