Maximizing Interoperability with BACnet
Part 1: What is BACnet Interoperability
What is BACnet Interoperability
July 2010 - Building Automation
Ask most facility managers what BACnet means and they'll answer with one word: interoperability. The whole point of the protocol is that it operates across multiple systems.
BACnet has been so successful that all major building automation system (BAS) manufacturers now offer "BACnet systems." But the fact is that all so-called "BACnet systems" are not created equal. Simply buying products that offer BACnet capability doesn't necessarily guarantee interoperability within a BAS.
"It is reliable communication at both the device and network management levels," says Ben Dorsey, vice president of marketing for KMC Controls. "But it also is a standard, and some providers do a better job than others at implementing this standard. As such, certain things can inhibit interoperability. I always encourage facility professionals to be aware of these things so that their expectations can be met."
It's important for facility managers to dig below the surface of claims for interoperability of various systems. That's because true interoperability can bring benefits for the life of the system. Creating a BACnet-based, interoperable system provides a strong basis for future expansion, says Tom Zaban, executive vice president of sales and marketing at Reliable Controls.
"The whole 'future-proofing' concept is key here," Zaban says. "With whatever new equipment is added from here forward, facility managers need to consider that equipment's connectivity and data-sharing capabilities and ask themselves the important question, 'How do we want to grow our control systems?'"
The flexibility provided by an interoperable system becomes especially powerful for the "smartest" buildings.
"Designing an intelligent building and making it interoperable is the ultimate business value," says Marc Petock, vice president of global marketing and communications at Tridium, Inc. "The building can be operated at lower cost, meaning equipment and systems — lighting, HVAC, elevators, security — can run for a lot less money. It's easierÊfor maintenance and monitoring, too. You're able to manage and control all interoperable building systems 24/7 from anywhere. You can pull up the interface on your Blackberry orÊother PDA and make it work as easily as you can from inside the maintenance department."
Those are powerful benefits. But it takes a little homework on the part of facility managers to ensure that they get those benefits.
In the past, if an existing building system, such as a chiller, came from a particular manufacturer, facility managers would need to assure that they had that same company's front-end software on their computers if they wanted to make any changes to the system remotely.
"But, if you operate with BACnet, you can access an entire building's systems — not one, but all — through a Web browser on any computer," says Mike Olson, power and controls sales manager for ABB.
Interoperability allows control systems manufactured by different vendors to work together, sharing data as required via a Web-based interface that operators can access through a single front end. An open interoperable system is based upon an open standard, such as BACnet, that can be used by any manufacturer without requiring licensing fees or restrictions on use.
"It helps give you better access to information," says Roy Kolasa, open system integration manager at Honeywell Building Solutions. "This allows facility managers to make more informed, efficient business decisions."
As such, interoperability's ability to allow various building systems to work together to create new monitoring and control strategies gives facility managers the opportunity to achieve important operational goals. These include reduced energy consumption, occupancy-based control and general streamlined maintenance and operation. Interoperability can yield lower life-cycle costs, increased system flexibility and lower supplier risk.
"The ability to monitor and control a building's interconnected system can offer substantial savings in time and effort," says Larry Haakenstad, Alerton's director of sales. "The availability of information to multiple users can positively impact productivity, making it easier and less time-consuming to manage these systems."
There are various levels at which interoperability takes place:
"For various reasons, different vendors sometimes supply systems to different wings of a building. Or, on a large campus, different vendors may supply the BAS in different buildings," says Steve Tom, director of technical information at Automated Logic Corp. "This is particularly common if the systems are installed at different times, under different contracts."
This can present challenges, particularly if not all products in the system comply with an open protocol, such as BACnet.
Litmus Tests for Interoperability
For facility managers considering a BACnet-based interoperable system, it's worthwhile to determine if vendors can pass two important tests. One is to find out if the vendor has devices listed by BACnet Testing Laboratories (BTL), which tests devices to ensure that they have correctly implemented the BACnet features they claim to offer. BTL listing ensures that a product conforms to the BACnet standard. For a list of BTL-listed devices, visit: www.bacnetinternational.net/btl
Another important indication that a vendor will be able to deliver a truly interoperable BACnet system is to ensure that they've worked successfully with other vendors in the past. For case studies on successful multivendor BACnet installations, visit: www.bacnetinternational.net/success/stories.php
Maximizing Interoperability with BACnet