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Using Gateways for BACnet Integration

The Building Automation industry has seen migration from vendor-specific proprietary protocols towards BACnet which has provided tremendous benefits and choices to building owners and systems installers, resulting in lower ownership costs.

According to, a 2023 market study entitled "Market Penetration of Communications Protocols 2018 - 2027" shows that the global market share of BACnet has continued to increase its trend over the past 10 years and now stands at an interim 77% globally. The study was conducted by BSRIA, a well-known provider of market intelligence in HVAC and building automation and control. The study's five-year outlook forecasts continued growth in BACnet adoption with continued improvements to the standard.

BACnet provides the unifying protocol and universal access for not only operator workstations and global controllers but any value-added application that follows the BACnet standard. This includes not only being able to incorporate legacy, proprietary Building Automation Systems (BAS) into BACnet but also incorporating newer non-BACnet technologies into this common ecosystem.

A gateway can translate one protocol to another, and there are multiple protocol gateways available for integration to BACnet. Modbus is a popular protocol traditionally used in the energy industry that lends itself well for BMS integration with the use of a gateway. Modbus is commonly found in jobs such as boiler control, variable speed drives, and metering applications, but these devices lack BACnet compliance. Contemporary Controls' BASgatewayLX Modbus to BACnet Gateway supports up to 100 Modbus serial devices, with each device appearing as an individual BACnet device. It has one 10/100 Mbps Modbus TCP and BACnet/IP Ethernet port and an opto-isolated Modbus EIA-485 serial port for Modbus RTU or Modbus ASCII devices.

Chillers, energy meters and Variable Frequency Drives (VFDs) are an important part of any energy optimization strategy in building automation. More and more equipment manufacturers are incorporating BACnet for these devices but a Modbus to BACnet gateway provides a viable alternative. Heat Pump systems are also gaining popularity and can be integrated into the BMS with the use of a VRF to BACnet gateway.

As the BACnet protocol continues to gain the global market share, the ability to seamlessly integrate non-BACnet devices into a BACnet network becomes increasingly important. The BASgatewayLX makes Modbus device commissioning fast and easy thanks to pre-built device profiles and virtual routing. The virtual routing feature in the BASgatewayLX allows each connected Modbus device to appear as an individual BACnet compliant device. A device profile is required for each Modbus type device, and Contemporary Controls maintains a library of common device profiles available for download in the Modbus Mapping Support Materials section. If the device profile is not available, we will provide it upon request.

To learn more, visit the BASgatewayLX Modbus to BACnet Gateway product page.


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