Like most technologies, building automation has advanced just within our lifetimes at a rate that would have baffled facility managers and engineers in, say, the 1950s. Back then, automated buildings relied on pneumatic controls in which compressed air was the medium of exchange for the monitors and controllers in the system.
By the 1980s, microprocessors had become small enough and sufficiently inexpensive that they could be implemented in building automation systems. Moving from compressed air to analog controls to digital controls was nothing short of a revolution. A decade later, open protocols were introduced that allowed the controlled facilities to actually communicate with one another. By the turn of the millennium, wireless technology allowed components to communicate without cable attachments.
Here are some of the terms that we believe are most useful
Building Management System (BMS) and Building Control System (BCS) — These are more general terms for systems that control a building’s facilities, although they are not necessarily automation systems.
Building Automation System (BAS) — A BAS is a subset of the management and control systems above and can be a part of the larger BMS or BCS. That said, building management and building automation have so thoroughly overlapped in recent years that it’s understandable people would use those terms interchangeably.
Energy Management System (EMS) and Energy Management Control System (EMCS)— These are systems that specifically deal with energy consumption, metering, etc. There is enough overlap between what a BAS does and what an EMS does that we can consider these synonymous.
Direct Digital Control (DDC) — This is the innovation that was brought about by small, affordable microprocessors in the ‘80s. DDC is the method by which the components of a digital system communicate.
Application Programming Interface (API) — This is a term common in computer programing. It describes the code that defines how two or more pieces of software communicate with one another.
What makes the terminology particularly complicated is that the technology evolves so quickly that it’s hard to know at what point a new term needs to be applied. Then, you also have professionals in different countries using different terms but still having to communicate with one another. Just be prepared for the terminology to be in a state of flux.