HD67C03-5-G43-B2 – Industrial RS485 to MQTT Broker Converter with LAN and LTE SIM

HD67C03-5-G43-B2 Converter – RS485 to MQTT Broker with LAN, LTE SIM and Housing Type B.

The HD67C03-5-G43-B2 is an industrial communication converter designed to integrate devices operating on RS485 with modern IoT and IIoT platforms using the MQTT Broker protocol. As part of the HD67C03 series, this model provides reliable data translation between serial communication infrastructures and MQTT-based systems, enabling legacy industrial devices to become fully compatible with modern data architectures.

The 5-G43-B2 version extends the functionality of the RS485/MQTT conversion engine with support for LAN (Ethernet) and LTE mobile connectivity using a SIM card. This dual communication layer provides excellent redundancy, ensuring uninterrupted operation in distributed, remote or mobile environments.

The converter is equipped with a durable Housing Type B and screw-type terminal connectors, ensuring reliable wiring in industrial conditions. Its DIN rail mounting enables convenient integration into electrical and automation cabinets. All parameters match the HD67C03-5-G43-B2 datasheet and the MN67C03 technical manual, which also describes LTE functionality, SMA Female antenna support and MicroSIM handling.

RS485 to MQTT Broker – modern integration of serial devices with IoT

The converter enables complete data translation from RS485 into MQTT topic structures, allowing industrial serial devices to be integrated with cloud platforms, SCADA, BMS, analytics tools and other IoT systems.

• RS485 communication up to 115200 bps,
• DIP switch bus termination (per manual),
• serial-to-MQTT data mapping,
• MQTT publish/subscribe functionality,
• support for multiple simultaneous MQTT clients,
• compatibility with Modbus RTU and other serial protocols.

With this capability, the HD67C03-5-G43-B2 enables older RS485-based devices to operate within modern data ecosystems, including real-time monitoring, cloud dashboards, remote analytics and industrial automation frameworks.

MQTT Broker – a central industrial data hub

The device functions as a full MQTT Broker, not only as a gateway. This allows multiple clients, sensors and applications to connect to the device simultaneously for publishing and subscribing to MQTT topics.

Typical client types include:

• IoT sensors and field devices,
• PLC controllers,
• HMI panels and SCADA software,
• cloud and edge computing platforms,
• data analytics engines,
• monitoring and logging systems.

Its role as an industrial data hub makes this converter ideal for automation, building management, telemetry and infrastructure monitoring environments.

Dual connectivity: LAN + LTE SIM

The G43 version includes two communication channels:

• Ethernet (RJ45) – the primary interface for MQTT communication and setup,
• LTE SIM – mobile connectivity using a MicroSIM card.

This architecture enables:

• reliable network redundancy,
• connectivity in remote areas without wired networks,
• operation in mobile or temporary installations,
• independence from fixed infrastructure,
• support for external LTE antennas using SMA Female connectors.

The LTE interface makes this device well-suited for distributed and off-grid systems that rely on wireless data transfer.

Configuration using SW67C03 software and integrated webserver

The HD67C03-5-G43-B2 is configured using the dedicated SW67C03 software tool, which can be downloaded below:
DOWNLOAD

The software provides:

• RS485 parameter configuration,
• MQTT Broker setup and topic definitions,
• client list management,
• LAN and LTE configuration,
• firmware updates and diagnostics,
• data mapping into MQTT structures.

The device also includes an integrated webserver for:

• status monitoring,
• network diagnostics,
• real-time communication insights.

Industrial construction – Housing Type B and DIN rail mounting

The converter is designed for use in demanding industrial environments. It features:

• Housing Type B (Modulbox 4M),
• Dimensions: 70 × 60 × 95 mm,
• Mounting: DIN rail 35 mm,
• Weight: approx. 200 g,
• Screw-type terminals for RS485, power supply and signals,
• Operating temperature: -40°C…+85°C.

The unit’s rugged design ensures resistance to electrical disturbances, temperature extremes and vibration — essential for long-term operation in industrial fields such as energy, automation, utilities and process control.

Technical specifications

• Ports: RS485, Ethernet, SIM Card
• RS485 protocol: differential serial bus
• MQTT Broker: full publish/subscribe capabilities
• RS485 connector: 3-pin screw terminal block
• Network connectors: RJ45 + SIM
• RS485 speed: up to 115200 bps
• MQTT speed: 10/100 Base-T Autosensing
• Power supply: 8…24 V AC or 12…35 V DC
• Operating temperature: -40°C…+85°C
• Dimensions: 70 × 60 × 95 mm
• Weight: approx. 200 g
• Software: SW67C03
• Order code: HD67C03-5-G43-B2

If you need assistance selecting the right RS485 to MQTT Broker converter with LTE connectivity, or if you need support evaluating compatibility with your automation system, our engineering team is ready to assist.