BACnet Makes Friends


The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recently released a new version of the building automation and control networks (BACnet) building automation system protocol. BACnet Secure Connect (BACnet/SC) makes the protocol friendly with building IT networks, enabling easy and secure transfer of large amounts of data for the internet of things (IoT) age.

BACnet is an open industry standard that enables communication for applications such as HVAC, lighting control, access control, fire-detection systems and other applications in place since 1995. As of 2017, more than 700 products from more than 130 manufacturers were listed by the BACnet testing laboratory. BACnet’s global market share now exceeds 60%, according to BSRIA, an HVAC industry research firm in Chicago.

The BACnet protocol evolved to define various data links and physical layers such as ethernet, BACnet/IP, BACnet/IPv6, BACnet/MSTP, Zigbee, etc. BACnet/IP allowed for communication between devices in an internet protocol (IP) or ethernet network. While this made BACnet adaptable to a building’s IT infrastructure, it was not considered IT-friendly largely because it relied on standards, such as a security method, not widely adopted by the IT world.

“BACnet/IP took the principles of IT but tweaked it to support the needs of BACnet and the constrained devices it supported,” said Scott Ziegenfus, director, controls support and service at Hubbell Lighting Inc., Greenville, S.C. He serves as an officer and secretary for the ASHRAE SSPC135 BACnet committee, chair of the SSPC135 Data Modeling Working Group, co-chair of the BACnet international education committee and is a past recipient of the BACnet international leader of the pack award.

“Essentially, BACnet/IP required IT departments make the network adapt to BACnet instead of BACnet adapt to their network,” Ziegenfus said.

BACnet/SC took the next step of enabling BACnet to adapt to any secure IT network. Rather than the standard’s clause 24, the current BACnet security method, BACnet/SC requires the use of the TLS cybersecurity protocol preferred by IT professionals along with a secure sockets layer approach, earning the label, “secure connect.” Through this, the BACnet network becomes as secure as the IT network. BACnet/SC also enables building systems to connect through IT firewalls without any special configuration.

BACnet/SC works with and uses common IT protocols, meaning it can be installed and managed using any typical IT configuration. It also eliminates the need for static IP addresses and dependency on broadcast messaging.

Installers do not need to learn a new protocol because the BACnet language remains largely untouched. For existing systems, BACnet/SC is completely backward-compatible with currently installed systems. Nothing needs to be removed from an installed BACnet system to adopt to BACnet/SC, and no capability is lost, Ziegenfus said.

“Today’s users don’t need to learn anything new,” he said. “Those with an existing BACnet system that want to change the communications to BACnet/SC simply use a BACnet router because it is a different data link. The BACnet message stays the same, only the wrapper changes.”

The biggest benefit is it allows building systems to confidently integrate IT networks by enabling the secure flow of large amounts of data on the premises, EDGE or cloud. This better positions BACnet for a role in the IoT.

As part of this, BACnet/SC facilitates integration with other building system networks, such as networked lighting controls. The larger the project, the more likely the lighting control system will be integrated with the building automation system.

By using BACnet/SC, the level of IT conversation and overall time required to ensure a smooth integration are lessened. As such, BACnet/SC offers the lighting industry a protocol enabling integration with both popular building automation systems and IT networks and supported by a security standard widely adopted by IT departments.

“BACnet is already arguably the most prominent building management system protocol used today,” Ziegenfus said. “This helps establish a strong future leadership position. By keeping the widely adopted existing protocol, but adding an element of IT friendliness, BACnet maintains its dominance and rate of expansion throughout the world.”

To learn more about the protocol and product availability, visit or contact preferred manufacturers of BACnet-based building systems.

Stay Informed Join our Newsletter

Having trouble finding time to sit down with the latest issue of
ELECTRICAL CONTRACTOR? Don't worry, we'll come to you.