HD67938-MSTP-B2 BACnet MSTP Slave to MQTT Converter for Secure IoT Integration

Industrial BACnet MSTP Slave to MQTT converter, housing type B (wide), DIN rail mount.

HD67938-MSTP-B2 allows to publish and get the data into/from a MQTT Server using a BACnet Master (like PLC, Supervisory System etc.). These gateways allow a fast and easy access to the IoT world and they are compatible with IoT Servers that support MQTT. The MQTT communication can be encrypted using TLS / SSL protocols, ensuring a SECURE and SAFE communication.

The HD67938-MSTP-B2 is a reliable solution for connecting BACnet MSTP networks with modern MQTT-based IoT infrastructures. Acting as a BACnet MSTP Slave, it communicates with a BACnet Master device over RS-485, while simultaneously publishing or receiving data through an MQTT broker. This ensures that legacy automation systems can easily be integrated with new IoT platforms, bridging the gap between traditional BMS solutions and cloud-based applications.

The device is equipped with two communication interfaces: an RS-485 port for BACnet MSTP and an Ethernet port (RJ45) for MQTT communication. It supports BACnet MSTP data rates up to 115200 bps, while the Ethernet interface provides 10/100 Base-T autosensing capability. This combination ensures efficient, stable, and scalable data transmission across both protocols, making it suitable for demanding industrial applications.

Designed for industrial use, the converter comes in a wide housing type B with DIN rail mounting, allowing easy installation in control panels or cabinets. With a broad operating temperature range from -40°C to +85°C, it guarantees long-term reliability even in harsh environments. Power flexibility is also provided with a range of 8…24VAC or 12…35VDC, making integration seamless across various electrical infrastructures.

Cybersecurity is a critical factor in today’s IoT deployments. With TLS/SSL support, the HD67938-MSTP-B2 ensures secure transmission of sensitive building and industrial data, protecting systems from unauthorized access or cyber threats. This makes it compliant with modern Industry 4.0 requirements, ensuring trust and reliability in energy monitoring, smart building, and critical infrastructure applications.

Configuration is simple and user-friendly through the free SW67938 software. The tool allows engineers to map BACnet objects to MQTT topics, adjust baud rates, and enable security parameters quickly and efficiently. This helps reduce commissioning time and avoids complex programming, making it ideal for system integrators who need fast deployment and stable performance.

Typical use cases include HVAC automation, lighting management, energy monitoring, and the integration of existing BACnet MSTP networks with modern IoT dashboards. The compact design (60 x 36 x 95 mm) and lightweight build (approx. 200 g) make it easy to install in limited-space control cabinets, providing flexibility for both small and large-scale projects.

Specifications:

• Ports: 1x Ethernet, 1x RS-485
• Ethernet protocol: MQTT
• BACnet protocol: BACNet MSTP Slave
• Data Rates BACnet: Up to 115200 bps
• Data Rates MQTT: 10/100 Base-T with autosensing
• BACnet MSTP connector: RS-485
• MQTT connector: RJ45
• Power supply: 8...24VAC 12...35VDC
• Power supply connector: 2-way 5mm terminal block
• Operating temperature: -40°C / +85°C (-40°F / +185°F)
• Dimensions: 60 mm x 36 mm x 95 mm (DxWxH)
• Weight: approx. 200 g
• Mechanical fixing: DIN Rail mount
• Software: SW67938
• ORDER CODE: HD67938-MSTP-B2

Configurator – Software SW67938 FREE DOWNLOAD

Manufacturer's warranty: 24 months

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