BACnet vs. Modbus: What to Consider

July 13, 2023
Richard Theron

When it comes to industrial and commercial automation, should you use BACnet® or Modbus®?
The answer is “yes.”

Both of these open protocol standards are designed to enable device communication and are
found among tens of thousands of BMS (building management systems) worldwide.

What is BACnet?

BACnet, which stands for Building Automation Control Network, is a popular protocol that’s been
around since 1995 and has a deployment of more than 25 million devices around the world.
Developed and maintained by the American Society of Heating, Refrigerating, and AirConditioning Engineers (ASHRAE), BACnet facilitates cross-communication.


By allowing devices from varying manufacturers within HVACR, lighting control, fire and life
safety, and other building automation functions to talk with one another.

What is Modbus?

Introduced in 1979 by Schneider Electric (then known as Modicon), Modbus is an even older
protocol than BACnet. Today, you can find more than 7 million nodes in North America and

Although used in BMS today, Modbus was originally developed as a way to transmit information
between programmable logic controllers (PLCs).

BACnet vs. Modbus: What’s the Difference?

BACnet and Modbus are both open communication protocols, which means that anyone can
design and manufacture BACnet or Modbus equipment without the need for proprietary
technology, tools, or fees.

Both protocols have a few other things in common—and quite a few differences, too. Here’s a
side-by-side comparison of the features and benefits of BACnet and Modbus.

The Evolution of BACnet vs. the Stasis of Modbus

Both BACnet and Modbus have a substantial installation base. BACnet, however, has garnered more than half the market share and has a growing adoption rate for one simple reason: BACnet continues to evolve, adding new objects and capabilities that are aligned with modern-day digital advancements and connectivity capabilities.

Most recently, ASHRAE introduced BACnet Secure Connect (BACnet/SC). According to ASHRAE, BACnet/SC is …

… a secure, encrypted communication datalink layer that is specifically designed to meet the requirements, policies, and constraints of minimally managed to professionally managed IP infrastructures.

In other words, this newest addition to the protocol is a proactive response to cybersecurity threats. BACnet/SC ensures that every device is authenticated and authorized to use a network, thereby protecting network security and information and infrastructure integrity.

BACnet vs. Modbus: Making the Choice

While each protocol has its rightful place, many OEMs and system integrators are considering making the switch to BACnet. If that’s you, then you need a powerful solution to make the most of BACnet’s capabilities.

The MSA QuickServer gateway is just that solution. FieldServer can connect your HVAC units, boilers, chillers, lighting systems and fire panels so that you get the data you need to monitor and control your facility effectively and efficiently.

To learn more, read “The 4 Amazing Benefits of a Good BACnet Router” or request more information today.

Richard Theron
Richard Theron is the product line manager for FieldServer at MSA, where he works intimately with companies in the building automation, industrial automation, energy management and life safety markets to help them cloud-enable their equipment.

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