Designing a building automation system with open protocol communication and intelligent electronic devices

Building Automation System (BAS) is a microprocessor-based control network setup for controlling a building’s technical service systems such as air conditioning, ventilation, lighting, and hydraulics. BAS main microcontroller automatically handles all electronics in the building. To control the liked devices to suit the needs of the buildings’ occupants, the controller needs to be smart or intelligent. The system will be very flexible if the communication network between control and device used an open communication protocol. In this paper, we present a miniature BAS solution implemented using intelligent electronic devices (IED) as controlling devices. The system is built using 8-bit microcontrollers, sensors, and actuators. There are three IED in use, each handling lighting, air conditioning, and water pumps respectively. Communication between the devices and the human-machine interface (HMI) used the free and open Modbus TCP protocol.