While it seems like just yesterday, it is now 21 years since the BACnet standard, ASHRAE 135, was approved and published. Since then, much has happened. We had a brief, but furious, industry debate over the need for open protocols, and battles over which protocol to use. Over the years, it has largely settled out: Essentially all HVAC controls suppliers offer systems that use BACnet and provide fairly strong support for other protocols such as LonWorks and Modbus, along with various uses of XML and other web standards. In many ways, it feels like this is an issue that has been resolved and no further work is needed.

This really could not be further from the truth. While it should be expected that robust open protocols like BACnet will continue to be widely used, readily supported, and continually enhanced, we should also expect that new protocols will be needed for markets, applications, and use cases that are not readily supported by a control protocol such as what was originally defined in BACnet. Here are some examples of what will need to be supported in future protocol implementations.

  • Semantics. One thing we have learned in doing systems integration and data analysis is that it isn’t just a matter of being able to integrate but of being able to understand what you have connected to. This meaning of data is semantics. Standards for semantics, such as being proposed in project Haystack, are key to having better operating integrated systems.

  • Cross-industry support. Different industries have gravitated to different interoperability standards. Moving to common standards will make integration easier to implement broadly. Note that this includes not only lighting and HVAC applications but in the future also vehicle chargers, solar panels, etc.

  • Business and grid support. Control systems will be expected to readily provide data to business systems and to bring data to and from the grid (often called Building to Grid). These will largely be IT-based standards.

  • Small commercial and residential support. Today’s solutions are fairly commonly applied in larger commercial buildings. Future solutions are also needed that can be used for integration and connection of smaller commercial buildings as well as residential applications. While ideally the same set of standards could be used for all building applications, it may make more sense to have one set of solutions for consumers/residential applications and another for commercial applications.

There is ongoing work from a number of groups to evaluate and develop new and expanded open protocols. ASHRAE is very active in expanding BACnet, but work is also ongoing from groups including NIST and the DOE to help define standards for expanded capabilities and functionality for open and interoperable systems. ES