Building and Campus Automation
Building automation is the automatic centralized control of a building's heating, ventilation, and air conditioning, lighting and other systems through a Building Management System (BMS) or Building Automation System (BAS). The objectives of building automation are improved occupant comfort, efficient operation of building systems, and reduction in energy consumption and operating costs. A BAS should reduce building energy and maintenance costs compared to a non-controlled building. Most commercial, institutional, and industrial buildings built after 2000 include a BAS. Many older buildings have been retrofitted with a new BAS, typically financed through energy and insurance savings, and other savings associated with pre-emptive maintenance and fault detection.
Technology advancements in cloud-based building automation services and smartphone and tablet interfaces grant building owners an incredible degree of personalization in the way they interface with their building systems. Systems can be personalized on a wide scope such as turning off lights during unoccupied times, or on a smaller scope such as having specific room temperature settings for certain personnel.
The Connectivity Challenge
A key requirement for a BMS or BAS implementation is that various devices and subsystems used in the building to implement specific HVAC or lighting or security or metering functions need to be physically inter-networked and logically integrated into the centralized management system, and furthermore into the cloud for remote management. The challenge is that many devices or subsystems in the building speak different languages or “field" protocols that need to be translated into the management protocol used by the BMS/BAS.
Protocols are a set of standards/rules for data exchange within or between computers, networks, or programs. One can think of protocols as being different languages that machines use to communicate with one another.
Although it is common to connect Modbus to BACnet, the real world is a “protocol soup". For example, a building may have standardized on BACnet/IP or a JCI Metasys N2 based management, but may need to incorporate a heating subsystem based on LonWorks, a fire and gas detection subsystem based on Modbus, a metering subsystem based on M-BUS, a fire alarm control system based on the vendor's proprietary protocol, an event logger that speaks SNMP, and a Programmable Logic Controller (PLC) that speaks Ethernet/IP. Furthermore, the facility manager may have a requirement to log critical alarms and data points in the cloud, and may want to use a modern standard like REST or JSON or XML to connect the building to the cloud in a secure manner.
The Need for Protocol Gateways
Facility managers can place the integration requirement either on their integrator or on their equipment and subsystem providers (the Original Equipment Manufacturer - the OEM). Integrators buy and use specialized protocol gateways to connect different best-of-breed devices and subsystems developed by OEMs to the centralized management system and the cloud. Alternately, the building specification can insist that every selected device or subsystem OEM must speak an agreed upon protocol in order to simplify the integration task. In this case, it is the OEM that has to effectively embed a protocol gateway inside their device to translate from their preferred protocol to the specified protocol.
Additional Campus Automation Requirements
University, government, or business campuses are often complex organizations incorporating many different building controls that have been implemented independently. For example, a typical campus might have multiple types of fire alarm panels added over different periods of time. In addition, the buildings on a campus may range from a historical building to a modern biotechnology laboratory requiring vastly different control approaches. The campus facility manager is responsible for bringing the diverse products and subsystems into a common central building control system to monitor energy usage, maintain safety, and provide the necessary learning and working environment for the occupants.