The MQTT.box from Wiesemann & Theis is a versatile, compact, and industrial-grade solution for the IoT and automation world. It is based on the proven Mosquitto MQTT broker, one of the most reliable messaging systems for machine-to-machine communication, and is designed specifically for professional DIN rail deployment. With two separate network interfaces, it enables secure data transfer between different network segments – ideal for Industry 4.0 and building automation systems.

Featuring user management, an Access Control List (ACL), web-based configuration, PoE power supply, and rugged hardware, the MQTT.box provides everything needed for modern automation infrastructures to ensure reliable and secure communication.

MQTT broker on DIN rail – Publish/Subscribe communication

MQTT (Message Queuing Telemetry Transport) is a lightweight communication protocol globally established as a standard in IoT and industrial automation. The MQTT.box acts as a central hub (broker) that receives messages from publishers and distributes them to subscribers. Its foundation is the Mosquitto broker, a well-known open-source project respected for stability, performance, and protocol compliance.

For example, a sensor can periodically publish measurement data to a topic, while controllers or dashboards subscribe to that topic to receive updates. This creates a structured, modular communication architecture that is efficient, resource-friendly, and scalable – ideal for data-intensive applications.

Dual network interfaces for increased security

A key advantage of the MQTT.box is its separation of two distinct network segments. Through dual Ethernet ports, data exchange can occur without direct access between networks. This is especially valuable in security-critical scenarios such as segregating the production network from the corporate IT network.

Clear segmentation prevents unauthorized access while maintaining reliable MQTT communication between both segments. This makes the MQTT.box suitable for applications with high IT security requirements in Industry 4.0 and building automation environments.

User management and access control (ACL)

To secure data exchange, the MQTT.box offers built-in user management and ACL functionality. Administrators can assign individual login credentials to each client and define which MQTT topics can be read or written. This allows granular permissions for different users or devices.

Example: A sensor may only publish to its dedicated measurement topic, while a building management system can subscribe to specified topics only. Role-based access control ensures data integrity while preserving flexibility and scalability.

Universal MQTT compatibility

The MQTT.box supports all MQTT versions (MQTT 3.1, 3.1.1, and 5.0) and integrates effortlessly with popular automation and IoT platforms such as Node-RED, Home Assistant, Siemens MindSphere, PRTG, or AWS IoT Core. It serves as a universal communication interface for devices from various manufacturers.

Flexible network integration

The dual Ethernet interfaces (10/100BaseT) with auto-MDIX allow flexible integration into almost any network. A dedicated subnet for IoT devices can be maintained while the second port connects data to higher-level IT systems. This structure enables secure cross-site communication management.

Web-based management and simple configuration

Configuration of the MQTT.box is user-friendly via web-based management. Administrators can manage user accounts, ACLs, network settings, and MQTT topics directly from a browser. Clear menu structures and secure HTTPS encryption enhance usability and security.

Additionally, Wiesemann & Theis WuTility software enables quick initial setup – operational in just three clicks. Even users without advanced networking experience can deploy a professional MQTT infrastructure.

Power supply and energy efficiency

Designed for maximum flexibility, the MQTT.box can be powered via Power-over-Ethernet (PoE) or an external 24–48 V DC supply. PoE reduces installation complexity by eliminating the need for separate power cabling. Buffer capacitors allow secure shutdown during power loss, protecting against data loss.

Its energy-efficient design ensures minimal power consumption, making it ideal for continuous operation in energy-optimized systems.

Standards compliance and long-term reliability

The MQTT.box meets key international standards:

• EN 61000-6-2: immunity for industrial environments
• EN 55032:2015 + A1 Class B: emissions
• EN 61000-3-2 / EN 61000-3-3: electromagnetic compatibility

Compliance ensures interference-free operation in both office and production settings. Built for durability, it includes a five-year warranty to affirm Wiesemann & Theis quality standards.

Practical application examples

• Building automation: temperature, lighting, and energy monitoring via MQTT, with separated network segments for external sensors and internal control systems
• Industrial automation: production machines publish process data over MQTT while analytics tools process information completely isolated from the corporate network
• Smart energy: centralized monitoring and control of electricity meters, PV inverters, or charging infrastructure

Easy integration into existing systems

Built on open standards, the MQTT.box interoperates smoothly with devices from various manufacturers supporting MQTT. It integrates seamlessly into control networks and acts as a secure communication hub between IoT devices and IT systems.

Compact MQTT broker for industry and building automation

The MQTT.box from Wiesemann & Theis is a modern communications solution that delivers MQTT-based data transfer directly on the DIN rail. Featuring dual network interfaces, integrated user management, ACL protection, PoE support, and web-based administration, it strikes an ideal balance between performance, security, and usability.

For Industry 4.0, building automation, or IoT projects, the MQTT.box provides a reliable, scalable, and secure platform wherever stability and efficiency are a top priority.