HD67G12-B2 – Modbus TCP Slave to HTTP/REST Server converter

HD67G12-B2 – Modbus TCP Slave and HTTP/REST Server integration.

HD67G12-B2 is an industrial Modbus TCP Slave / HTTP/REST Server converter by ADFweb, designed to integrate automation systems based on Modbus TCP with applications, clients and systems communicating through HTTP/REST. On the industrial communication side, the device operates as a Modbus TCP Slave, so it can be accessed by a supervisory Modbus TCP Master in an Ethernet network. On the web communication side, the converter works as an HTTP/REST Server, allowing external HTTP/REST applications to retrieve or exchange data according to the configured endpoints. The HD67G12-B2 model is the wired LAN version, equipped with 1 Ethernet RJ45 port, without LTE module, eSIM or VPN service. This makes it suitable for installations where communication is handled locally through a stable Ethernet infrastructure, without the need for cellular transmission.

Modbus TCP Slave / HTTP/REST Server converter for automation system integration

HD67G12-B2 enables classic industrial communication to be connected with web communication based on HTTP/REST. In practice, this means that data available on the Modbus TCP side can be made available to applications, REST clients, IIoT systems, reporting tools, supervisory platforms or software developed for a specific installation. The device is not a simple network adapter, but a configurable communication gateway in which the user defines the Modbus TCP parameters, HTTP/REST communication settings, endpoint list and data mapping. Unlike HTTP/REST Client variants, the HTTP/REST Server version can expose endpoints that are accessed by an external HTTP/REST client. This is useful when the higher-level application has to actively retrieve data, send requests or integrate the converter into an existing web-based architecture. The HD67G12-B2 model is well suited for control cabinets, local supervision systems and installations requiring predictable Ethernet communication.

Ethernet RJ45, isolation and DIN rail mounting

The HD67G12-B2 uses 1 Ethernet RJ45 port for device configuration, Modbus TCP communication and HTTP/REST communication. The Ethernet interface supports 10/100 Base-T Autosensing, allowing operation in standard industrial and technical Ethernet networks. According to the manufacturer’s documentation, the Ethernet connection should be made using at least a Category 5E cable, and the maximum cable length should not exceed 100 m. The interface has two different MAC addresses, one for the HTTP/REST side and one for the Modbus TCP side, which reflects the communication architecture of the device. The converter also provides electrical isolation between Ethernet and Power Supply, improving stability in industrial environments and reducing the influence of disturbances between the communication section and the power section. The type B Modulbox 4M housing is designed for 35 mm DIN rail mounting, making installation straightforward in automation cabinets.

HTTP/REST endpoints and Modbus TCP data mapping

An important function of the HD67G12-B2 is the possibility to define Modbus data mapped inside HTTP/REST endpoints. The software allows the user to specify which data from the Modbus area should be available on the HTTP/REST side and in which format it should be exposed. Dedicated template keywords are used to link the data, defining the variable format, the starting bit in the device’s internal memory and the data size in bits. Supported formats include unsigned integer, signed integer, float, binary, string, hexadecimal and Base64. This allows the converter to expose data in a structure expected by the HTTP/REST application, for example in a JSON-like format or in a layout required by a specific system. It is particularly useful for integrating measured values, counters, alarms, operating states, process parameters and diagnostic data.

Product features

• Modbus TCP Slave / HTTP/REST Server conversion in one industrial device.
• Wired LAN version without LTE module, eSIM or VPN service.
• 1 Ethernet RJ45 port for configuration, Modbus TCP communication and HTTP/REST communication.
• Operation on the industrial side as a Modbus TCP Slave.
• Operation on the web communication side as an HTTP/REST Server.
• Support for 10/100 Base-T Autosensing for Modbus TCP and HTTP/REST communication.
• Configuration of HTTP/REST parameters, Modbus TCP line parameters and endpoints.
• Possibility to define the list of Modbus TCP requests in read and write mode.
• Template-based mapping of Modbus data inside HTTP/REST endpoints.
• Support for data formats: unsigned integer, signed integer, float, binary, string, hexadecimal and Base64.
• Electrical isolation between Ethernet and Power Supply.
• Wide power input range: 8..24V AC and 12..35V DC.
• Consumption at 24V DC: 5 W/VA.
• Type B Modulbox 4M housing suitable 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: HD67G12-B2
• Device type: Modbus TCP Slave / HTTP/REST Server - Converter
• Housing: type B, Modulbox 4M
• Connectors type: Terminal Blocks Connectors, Fixed Screw Terminal
• Ports: 1x Ethernet
• Modbus TCP protocol: Modbus TCP Slave
• Ethernet protocol: HTTP/REST Server
• 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: SW67G12
• Order code: HD67G12-B2

Configuration and diagnostics

The HD67G12-B2 converter is configured using SW67G12 software. The program allows the user to define HTTP/REST communication parameters, set the Modbus TCP line parameters, define the list of endpoints accessible from the HTTP/REST side, define the list of Modbus TCP requests in read and write mode and update the device. The software works with MS Windows systems and requires .NET Framework 4. The ADFweb Discovery Tool can be used to find the device in the network and check its IP address. The converter also includes a recovery button that allows the device to be switched into Recovery Mode in case of an incorrect firmware update or a problem affecting normal operation. Four LEDs provide information about device state, Modbus TCP communication, HTTP/REST communication and error state.

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