HD67C05-5-B2 Industrial Modbus Slave and MQTT Broker Converter for RS485 and Ethernet

HD67C05-5-B2 – Industrial Modbus Slave and MQTT Broker Converter for RS485 and Ethernet.

The HD67C05-5-B2 is an industrial communication converter from ADFweb that combines Modbus RTU in Slave mode with a fully integrated MQTT Broker, enabling seamless data exchange between RS485-based automation systems and modern IoT or cloud platforms. Designed in the compact type-B DIN rail housing (Modulbox 4M), the device offers screw terminals for RS485 and an RJ45 Ethernet interface.

The converter provides galvanic isolation between the power supply and Ethernet, supports a wide 8…24V AC / 12…35V DC power input range, and operates in harsh environments with temperatures from -40°C to +85°C. These features make it suitable for industrial, BMS, energy and remote monitoring installations.

Key Features and Advantages

• Modbus RTU Slave (RS485) – supports Holding and Input Registers with fully configurable mapping.
• Integrated MQTT Broker – topic management, client permissions, QoS settings, JSON/RAW formats, cyclic publishing.
• Galvanic isolation between Ethernet and the power section for increased electrical safety and EMC robustness.
• SW67C05 software – configuration of Modbus settings, MQTT parameters and Ethernet network options.
• Diagnostic LEDs – visual indicators for RS485 activity, network communication, device status and error conditions.
• Industrial-grade design – wide temperature range, stable transmission and long RS485 line support (up to 1200 m).
• DIN rail mounting – compact housing suitable for panels and industrial cabinets.

How the Converter Works

The HD67C05-5-B2 maps data from MQTT topics into Modbus registers, allowing PLCs, SCADA systems and BMS controllers to access cloud or IoT data via standard RS485 communication. Conversely, the device can publish Modbus data to MQTT topics—either cyclically, on value change, or on command—enabling real-time integration between legacy RS485 networks and modern MQTT ecosystems.

With SW67C05, users can configure client permissions, supported payload formats (RAW/JSON), topic templates, MQTT Bridges and detailed access rules. This makes the converter a central data exchange point in hybrid Modbus-MQTT architectures.

Ports and Connectivity

• 1× RS485 Modbus Slave – 3-pin screw terminal (5 mm pitch)
• 1× Ethernet RJ45 – 10/100 Mbps autosensing
• 2-pin power connector – screw terminal, 5 mm pitch

Technical Specifications

• Modbus Slave speed: up to 115200 bps
• MQTT Ethernet: 10/100 Base-T autosensing
• Power supply: 8…24 V AC or 12…35 V DC
• Operating temperature: -40°C to +85°C
• Dimensions: 70 × 60 × 95 mm
• Weight: approx. 200 g
• Mounting: DIN rail 35 mm
• Software: SW67C05
• Order code: HD67C05-5-B2

Applications

• Industrial automation and RS485 device integration
• IoT systems based on MQTT communication
• SCADA and BMS platforms
• Energy monitoring and photovoltaic installations
• Remote telemetry and industrial data acquisition
• Bridging legacy RS485 devices with cloud applications

The HD67C05-5-B2 is a reliable and robust industrial converter that unifies Modbus RTU and MQTT in a compact DIN rail-mounted device. With stable communication, flexible configuration via SW67C05 and industrial resilience, it is an excellent choice for automation systems, IoT gateways and hybrid Modbus–MQTT applications.