Hattersheim, 28. Jul. 2025 – The innovative container-based application, the netFIELD App Modbus to MQTT Adapter, enables seamless integration of Modbus RTU and TCP data into IIoT platforms via MQTT, providing a highly efficient solution for data acquisition. It simplifies the connection of existing systems and serves as an ideal foundation for modern, data-driven industrial applications. Read more in our news!

Hilscher launches new netFIELD app for data acquisition in Modbus networks

Hattersheim, July 28, 2025 – Hilscher Gesellschaft für Systemautomation mbH has released a new app for IT/OT integration. This innovative software application enables seamless integration of Modbus data into IIoT platforms and provides an efficient way to acquire and transfer data.
The new netFIELD app acts as a Modbus to MQTT adapter and supports both Modbus RTU and TCP. Designed as a software container, it converts Modbus data into MQTT messages, greatly facilitating communication between Modbus devices and MQTT-based applications.

The new platform-independent container allows host devices, such as edge gateways, to exchange data between Modbus RTU or TCP server devices and user applications over an MQTT message bus. Users upload simple JSON-encoded Modbus device description files through the app’s built-in user interface. These Modbus device description files, including the required device data such as the supported register and coil configurations, serve as the basis for configuring Modbus read/write transactions with the devices.

This new app is ideal for upgrading Modbus-based systems with IIoT or smart services, as it leverages field and control data from Modbus devices to gain real-time insights into physical processes. For example, this enables faster response times for predictive maintenance or increased system productivity through real-time data analysis that leads to derived actions.
The Modbus protocol is particularly widespread in the energy sector. Many devices used in power generation, energy storage and distribution, as well as in load monitoring and building automation, are equipped with Modbus RTU or Modbus TCP interfaces. With the new netFIELD Modbus app, companies can quickly and easily retrofit their systems for energy monitoring and energy management.

The app also has a proxy function. The Modbus proxy acts as an intermediary between Modbus RTU devices and Modbus TCP clients. In this role, the app translates Modbus TCP requests into the Modbus RTU protocol. This allows, for example, Modbus RTU devices to be integrated into server applications that only support the Modbus TCP protocol.

Technical benefits
  • Compatible with all Modbus RTU and Modbus TCP server devices
  • Supports reading and writing of all types of registers and coils
  • Comfortably configurable via the integrated web user interface
  • Efficient configuration with JSON encoded Modbus device description files
  • No restrictions on the number of supported Modbus devices or the volume of communication data
  • The most efficient way to upgrade systems with Modbus devices to modern IIoT technologies and smart services by using the widely adopted MQTT protocol as the application data interface
Economic benefits
  • Fast and cost-effective integration of Modbus devices into IIoT environments
  • Facilitates comprehensive analysis of Modbus data, allowing users to gain valuable insights to increase plant productivity
  • Enables in-depth examination of Modbus device signal behavior for optimization, resulting in more efficient plant operation
  • Provides data logging and tracking throughout the lifecycle of asset processes to ensure transparency and traceability
  • Supports the implementation of automated predictive maintenance scenarios, reducing the need for manual monitoring and saving valuable human resources
  • Make energy consumption transparent and reduce energy usage – many energy meters support Modbus

Example setup of an application using the netFIELD Modbus Adapter App.

Description The app runs on a host device, such as an edge gateway equipped with at least one serial port (for Modbus RTU) or at least one Ethernet port (for Modbus TCP). Depending on the specific use case, the app must be configured for either Modbus RTU or Modbus TCP operating mode. Devices can be connected either directly to a port on the host or in a daisy-chain with multiple Modbus devices.

Key facts

  • The app’s host is physically connected to the Modbus devices through one of its serial ports or one of its Ethernet ports.
     
  • The app periodically reads and writes data from the configured Modbus devices.
     
  • The data exchanged with the Modbus devices is made available to the user via MQTT messages as the data interface.
     
  • By functioning as an MQTT client, the app is compatible with any MQTT broker.
     
  • The MQTT broker can be operated either locally on the same host devices as the app or externally on a different device.
     
  • One or more MQTT clients can access the Modbus data via the central MQTT broker.
A diagram showing the integration of MQTT clients with a central broker and the connection to multiple RTU/TCP server devices via a Modbus Converter App hosted on an Edge Gateway.
Target group

The netFIELD app is intended for companies and users who want to exchange Modbus data from Modbus RTU or TCP devices for their industry 4.0 use cases. Modbus is one of the most widely used protocols for data exchange between various electronic devices in industrial environments. Integrating Modbus support into Hilscher’s IIoT range is therefore a logical next step.

Operating requirements

To run the netFIELD app, a host device with a container engine is required. The app acts as an MQTT client and converts read and written Modbus data to and from MQTT messages. An internal or external MQTT broker is required to publish and subscribe to these topics. 
The host must have either a physical Ethernet or serial interface to connect to the Modbus devices. The app can be configured to work in either RTU or TCP mode.

Problem solving

The netFIELD app makes it easy to upgrade any Modbus-capable installation with an edge device that acts as a Modbus client and enables seamless exchange of Modbus data via a MQTT broker. This makes it easier to upgrade older Modbus systems and to set up new installations where the edge device is an integral component from the very beginning.

Related links

Programming code abstract technology background of software developer and Computer script
Scalable IIoT Solutions with netFIELD: Future-Ready at the IT-OT Edge

With netFIELD, you benefit from Hilscher’s deep expertise in industrial communication—empowering reliable IT-OT convergence and Industry 4.0 implementations. The platform enables you to efficiently operate, manage, and scale edge gateways and IIoT applications—whether cloud-connected, hybrid, or fully on-premise. 

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Markus Hoppe
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