HD67C03-2-G43-E-VPN-B2 – Industrial RS232 to MQTT Broker Converter with VPN, LAN, LTE SIM and eSIM

HD67C03-2-G43-E-VPN-B2 Converter – RS232 to MQTT Broker with VPN, LAN, LTE SIM and eSIM in Housing Type B.

The HD67C03-2-G43-E-VPN-B2 is an advanced industrial-grade communication converter designed to integrate devices equipped with an RS232 interface with modern IoT and IIoT platforms based on the MQTT Broker protocol. This model is one of the most capable variants within the HD67C03 family, combining serial communication handling, Ethernet networking, mobile LTE data transmission, an integrated eSIM, and a secure VPN tunnel that ensures encrypted and reliable communication in remote environments.

Built in a robust Housing type B with screw-type terminal connectors, the converter is intended for demanding industrial installations. DIN rail mounting allows for simple integration into industrial control cabinets, while its compatibility with 8…24 V AC and 12…35 V DC power supplies ensures flexibility across different environments, including locations with variable supply conditions.

The full device specification is detailed in the technical documentation included with the product (MN67C03_ENG manual) and the model datasheet . The G43-E-VPN version is equipped with:

• RS232 (screw connector),
• Ethernet LAN (RJ45),
• LTE SIM slot (MicroSIM),
• built-in eSIM module,
• VPN service for encrypted communication,
• a fully functional MQTT Broker.

RS232 to MQTT Broker – modern integration of legacy devices with IoT platforms

The HD67C03-2-G43-E-VPN-B2 enables full translation of serial RS232 data into MQTT Broker structures, allowing older or legacy industrial devices to become part of modern IIoT ecosystems.

• RS232 communication up to 115200 bps,
• publishing RS232 data as MQTT messages,
• subscribing to MQTT topics and forwarding control messages to RS232,
• support for multiple simultaneous MQTT clients,
• configurable payload formats (JSON, Base64, float, integer and more).

With its integrated MQTT Broker, the device can operate as an edge node enabling decentralized data processing in industrial IoT architectures.

VPN – secure encrypted industrial communication

One of the device’s most important features is the embedded VPN service, responsible for creating fully encrypted communication tunnels. This ensures:

• secure data transmission between remote nodes,
• safe access to RS232-based hardware at a distance,
• elimination of risks associated with exposing public IP addresses,
• protected communication over LTE/eSIM mobile networks,
• compatibility with IoT/IIoT cloud systems, SCADA, and BMS platforms.

The VPN layer is particularly useful in distributed, mobile, remote, and telemetry-based automation architectures.

LAN + LTE SIM + eSIM – triple connectivity and full redundancy

The G43-E-VPN version offers three communication channels:

• Ethernet (RJ45) – the primary configuration and data interface,
• LTE SIM – mobile communication via MicroSIM,
• eSIM – embedded SIM for deployments without a physical card.

Using both LTE and eSIM provides:

• network redundancy,
• independence from wired Ethernet infrastructure,
• rapid deployment in any location,
• uninterrupted MQTT Broker and VPN communication.

According to the datasheet, the LTE/eSIM module features an SMA Female antenna connector, ensuring compatibility with industrial-grade antennas.

Configuration via SW67C03 software and integrated webserver

The converter is configured using the SW67C03 software tool and the integrated webserver. The configuration ecosystem provides full flexibility for defining MQTT message structures, serial parameters, and VPN profiles.

Software capabilities include:

• RS232 configuration,
• management of MQTT topics and clients,
• VPN setup (profiles, credentials, certificate handling),
• data payload mapping,
• firmware updates and diagnostics.

Software download: DOWNLOAD

Industrial design – durable Housing type B and DIN rail mounting

The HD67C03-2-G43-E-VPN-B2 is engineered for demanding industrial installations. Key characteristics include:

• Housing type B – compact and robust enclosure,
• Dimensions: 70 × 60 × 95 mm,
• Mounting: DIN rail,
• Power supply: 8…24 V AC / 12…35 V DC,
• Operating temperature: -40°C…+85°C,
• Weight: approx. 200 g,
• Connectors: screw-type terminal blocks.

Technical specifications

• Service: VPN
• Ports: 1× RS232, 1× Ethernet, SIM Card, eSIM
• RS232 speed: up to 115200 bps
• MQTT Broker communication: via Ethernet and LTE
• RS232 connector: 3-pin screw terminal block
• MQTT/Ethernet connectors: RJ45 + SIM + eSIM
• MQTT data rate: 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: HD67C03-2-G43-E-VPN-B2

If you need assistance choosing the right RS232/MQTT Broker converter with LTE, eSIM and VPN capabilities or verifying compatibility with your industrial network, our specialists are ready to help.