A Building Management System (BMS) or Building Automation System (BAS) is a centralized computer-based control network installed in modern facilities to monitor and optimize mechanical, electrical, and plumbing equipment.
1. Architecture of a Modern BMS Network
- Management Level: SCADA Workstations, Central Server, Cloud Analytics Interface.
- Automation Level: Direct Digital Controllers (DDC) executing control loop algorithms.
- Field Level: Temperature sensors, pressure transmitters, CO2 sensors, motorized control valves, and VFD speed drives.
2. Communication Protocols: BACnet vs Modbus
Modern BMS controllers integrate seamlessly with chillers, VFDs, and energy meters via open protocols: BACnet MS/TP or IP for HVAC equipment and Modbus RTU/TCP for electrical power meters and trip units.