This summer marks the 20th anniversary of the passage of ASHRAE Standard 135 — better known as “BACnet.” Over the past two decades, the building automation industry has largely been transformed from a business based upon proprietary communications to one where customers have options for open protocols including BACnet, LonTalk, Modbus, and others. Vendors now offer broad support for open protocol based systems, and standards such as BACnet are continuously being updated and improved.

As an industry then, have we “solved” the issue of interoperability? While we now have good choices in terms of robust protocols for use in commercial buildings, areas remain where more effort is needed. Here are a few key areas to look for continued improvements.


Device Support

Today, it is common to be able to specify HVAC controls that comply with open protocols such as BACnet. There are, however, many other building systems such as lighting, meters, elevators, IT equipment, kitchen appliances, solar panels, fire and security systems that should potentially be integrated. These systems follow a frustrating combination of open, industry-specific, or proprietary protocols, making integration complicated and expensive, if not impossible. With the new “Internet of Things” movement, expect to find more devices in buildings that are good candidates for integration. The need for easier device support is an area that needs to continue to evolve.


Management and Supervisory Support

Protocols such as BACnet can readily be applied through something as basic as a sensor or controller up through a workstation, but building systems continue to become more highly integrated, merging with the larger world of IT systems. For example, many BAS systems today are using web services (web browser, cloud storage, IP communications, etc.) as a key part of their operations. Future buildings will be more integrated with renewable resources and the grid. Expect to see more work in the area of how IT standards can readily be applied for building systems.


Information Management

Most of the current open protocol work has been focused on sharing data (points or objects) between devices and workstations. But critical operational information such as the definition of how devices are configured, programmed, and information is identified is not generally covered in the protocols; instead, it has been left up to the system supplier. This has proved to be an area of ongoing frustration for building owners as they experience the challenges of supporting various programming tools, integrating systems, and connecting to services such as analytics analysis. Efforts such as Project Haystack are attempting to set some guidelines for how to improve the area of semantics, but much more work is needed in this area to be able to move toward a “plug and play” solution.

Currently, organizations including the Department of Energy, Gridwise Alliance, and ASHRAE continue to work in these areas. Expect to see further changes and improvements so that systems can become even more open and interoperable.