HD67G11-B2 – Modbus TCP Slave to HTTP/REST Client converter

HD67G11-B2 – Modbus TCP Slave and HTTP/REST Client integration.

HD67G11-B2 is an industrial Modbus TCP Slave / HTTP/REST Client converter by ADFweb, designed to connect automation systems based on Modbus TCP with applications, servers and platforms that exchange data through HTTP/REST. On the industrial communication side, the device operates as a Modbus TCP Slave, so it can be accessed by a Modbus TCP Master in an Ethernet network. On the web communication side, it works as an HTTP/REST Client, allowing process data, machine status values and mapped variables to be sent to an HTTP/REST server. The HD67G11-B2 version is the wired LAN model, equipped with 1 Ethernet RJ45 port, without LTE, eSIM or VPN service. This makes it suitable for installations where communication is handled through a stable local Ethernet infrastructure inside control cabinets, industrial networks or automation panels.

Industrial Modbus TCP Slave / HTTP/REST Client conversion

HD67G11-B2 enables data exchange between industrial automation devices and web-oriented systems that use HTTP/REST communication. In practice, this means that values available on the Modbus TCP side can be transferred into a structure suitable for IT applications, IIoT platforms, data acquisition systems, middleware or custom software. The converter is not a simple wiring adapter, but a configurable gateway in which communication parameters and data structures are defined according to the target application. The user can set the Modbus TCP parameters, define the HTTP/REST parameters, configure the accessible endpoints and build the payload structure. This flexibility is useful when integrating PLCs, HMI panels, SCADA systems, local controllers or industrial monitoring devices with external software environments. The device provides a practical bridge between classical industrial protocols and modern REST-based communication.

Ethernet RJ45 communication and electrical isolation

The HD67G11-B2 uses one Ethernet RJ45 port for device programming, Modbus TCP communication and HTTP/REST communication. The Ethernet interface supports 10/100 Base-T Autosensing, allowing the converter to operate in common industrial and technical Ethernet networks. According to the device architecture, the interface uses two different MAC addresses, one for the HTTP/REST side and one for the Modbus TCP side. The converter also provides electrical isolation between Ethernet and Power Supply, which helps improve operational reliability in industrial environments and reduces the influence of disturbances between the communication section and the power section. The device can be powered with 8..24V AC or 12..35V DC, and the power connection is made through a 2-way 5 mm terminal block. Its type B housing is designed for 35 mm DIN rail mounting, making installation straightforward in automation cabinets and control panels.

HTTP/REST payload definition and data mapping

A key feature of the HD67G11-B2 is the possibility to define the HTTP/REST payload structure. Data from the Modbus side can be linked to the HTTP/REST side using template strings with specific keywords that define the variable format, the starting bit of the internal memory array and the data size in bits. Supported data formats include unsigned integer, signed integer, float, binary, string, hexadecimal and Base64. This allows the converter to prepare data in a format expected by the receiving HTTP/REST server, including JSON-style payloads and application-specific data structures. Such functionality is useful for transmitting measured values, machine states, alarms, counters, production parameters or process variables. The final behavior of the converter is defined through the configuration software, without the need to modify firmware or develop a dedicated embedded application.

Product features

• Modbus TCP Slave / HTTP/REST Client conversion in one industrial device.
• 1 Ethernet RJ45 port for configuration, Modbus TCP communication and HTTP/REST communication.
• Support for 10/100 Base-T Autosensing on both Modbus TCP and HTTP/REST communication.
• Operation on the industrial side as a Modbus TCP Slave.
• Operation on the web communication side as an HTTP/REST Client.
• Configuration of HTTP/REST parameters, Modbus TCP parameters and accessible endpoints.
• Template-based payload definition for HTTP/REST data exchange.
• Support for unsigned integer, signed integer, float, binary, string, hexadecimal and Base64 data formats.
• Electrical isolation between Ethernet and Power Supply.
• Wide power input range: 8..24V AC and 12..35V DC.
• Type B housing for 35 mm DIN rail mounting.
• Operating temperature range: -40°C/+85°C (-40°F/+185°F).
• LED diagnostics for device state, Modbus TCP communication, HTTP/REST communication and error state.

Technical specification

• Order code: HD67G11-B2
• Device type: Modbus TCP Slave / HTTP/REST Client - Converter
• Housing: type B, Modulbox 4M
• Connectors type: Fixed Screw Terminal
• Ports: 1x Ethernet
• Modbus TCP protocol: Modbus TCP Slave
• HTTP/REST protocol: HTTP/REST Client
• Modbus TCP connector: RJ45
• HTTP/REST connector: RJ45
• Data Rates Modbus TCP: 10/100 Base-T Autosensing
• Data Rates HTTP/REST: 10/100 Base-T Autosensing
• Power supply: 8..24V AC, 12..35V DC
• Power supply connector: 2-way 5 mm terminal block
• Consumption at 24V DC: 5 W/VA
• Operating temperature: -40°C/+85°C (-40°F/+185°F)
• Dimensions: 70 x 60 x 95 mm (D x W x H)
• Weight: 200g approx
• Mechanical fixing: 35 mm DIN rail mounting
• Software: SW67G11

Configuration and diagnostics

The HD67G11-B2 converter is configured using SW67G11 software. The tool allows the user to define HTTP/REST parameters, set the Modbus TCP line parameters, define the list of accessible endpoints from the HTTP/REST side and update the device. The software works with MS Windows systems and requires .NET Framework 4. The device can also be discovered in the network using ADFweb Discovery Tool, which helps identify its IP address. For maintenance and recovery operations, the converter includes a recovery button that allows the device to be switched into Recovery Mode if a wrong firmware update or another error compromises normal operation. Four LEDs provide diagnostic information about device state, Modbus TCP communication, HTTP/REST communication and error state.

ADFweb provides technical support for its devices and makes configuration tools and product documentation available for the corresponding product family. The product is covered by the manufacturer’s standard warranty, and service procedures can be handled according to ADFweb support and return policy.