In modern industrial plants, energy and building systems, and intelligent infrastructure, the precise control of 230V switching signals is becoming increasingly important. The Web-IO 4.0 230V Relay 1xNO, 1xCO from Wiesemann & Theis offers a state-of-the-art solution for users who wish to carry out switching operations reliably from a distance. It combines traditional relay technology with contemporary network communication, meeting the demands of Industry 4.0 and the Internet of Things (IoT).

This compact, network-enabled device has two bistable relay outputs – one normally open contact (NO) and one changeover contact (CO). Both are designed for direct operation with 230V mains voltage. The system not only enables straightforward remote control of devices such as lamps, motors, or heaters, but also allows integration into higher-level automation systems. By combining hardware safety, network connectivity, and browser-based control, the Web-IO 4.0 230V Relay offers a powerful platform for modern control tasks.

In addition, support for widely used communication protocols such as MQTT, OPC UA, and REST ensures seamless integration into IoT platforms, cloud services, and industrial control systems. This makes the device perfectly suited for use in smart buildings, manufacturing environments, and technical monitoring systems.

Powerful control and efficient technology

At the heart of the Web-IO 4.0 230V Relay are the two bistable relays. They retain their switching state even during a power outage – a feature that is particularly advantageous in critical applications. The NO output (normally open) and the CO output (changeover) are both rated for loads up to 16 A at 230V AC. This ensures reliable switching of both lighting circuits and high-power consumers.

Energy efficiency is further enhanced by the bistable design, as the relays only consume power during the switching operation. In the idle state, the last selected switching state is maintained. This minimizes energy loss and supports sustainable operation in automated environments.

Operation via intuitive web interface

Management, control, and monitoring are handled via a modern and multilingual web interface, available in both German and English. With its clear layout, relay states can be conveniently monitored and controlled in real time. Smart device users benefit from the mobile-optimized interface, which allows access from smartphones or tablets – ideal for on-site service technicians and IT administrators.

Access is via HTTP or HTTPS, ensuring secure communication within the network. Developers can use HTTP requests, AJAX, or JavaScript to access relay states or switch them directly from applications. The REST-API interface makes it easy to integrate into cloud-based monitoring systems or IoT management platforms. For cross-location control tasks, the proven box-to-box function is available, enabling 1:1 switching operations distributed across the IP network.

Automatic alarm and notification functions

The Web-IO 4.0 230V Relay offers an extensive range of alarm and notification mechanisms. Up to 30 actions can be individually configured to automatically trigger when relay states change. These include:

• Email notifications upon state change
• SNMP traps (version 1, 2, or 3) for network management systems
• HTTP commands to external systems or applications
• Direct switching of other Web-IO relays in remote networks

These features make the device a versatile control center, suitable for system monitoring, fault diagnosis, and preventive maintenance. This allows companies to react more quickly to faults and improve operating safety.

Seamless integration into IoT and industrial environments

With support for leading protocols such as OPC UA, MQTT, and REST, the device can be directly integrated into common IoT and automation platforms. Developers benefit from open APIs to implement custom control and data processing workflows. Furthermore, interfaces such as SNMP, Modbus TCP, Syslog, and Sensobase are also supported, ensuring seamless connectivity to IT monitoring or database solutions.

With integrated FTP support, switching operations can be automatically logged. These logs provide traceability for process states and can be used for audits, quality management, or documentation requirements.

Integrated data logger and time management

Another advantage is the built-in data logger, which automatically records state changes and switching operations. Depending on the configured logging frequency, data can be stored for weeks or up to 20 years. Export options include Excel, email, or FTP formats. An internal battery-buffered real-time clock and optional NTP synchronization provide precise timestamps – essential for tracking, analysis, and long-term documentation.

Application fields in practice and industry

• Building automation: control and monitoring of 230V lighting circuits, door drives, shutters, or heating systems.
• Remote control: triggering and monitoring of switching operations via the internet or internal networks.
• Process monitoring: documentation and control of 230V signals in manufacturing or laboratory processes.
• Home automation: automated lighting and energy management via web browser or app.
• Machine data acquisition (MDA): integration into production data acquisition systems.

Power supply and technical safety

Power is supplied via direct 230V AC (50 Hz) through a screw terminal connection. With its robust design and compliance with relevant EMC and safety standards (EN 61000-6-2, EN 55032:2015 + A1), the device is certified for both office and industrial environments. It ensures reliable and interference-free operation even under high electromagnetic loads.

Reliability and durability in continuous operation

The Web-IO 4.0 230V Relay is designed for continuous use and features robust mechanical and electrical construction. DIN rail mounting enables secure and space-saving installation in control cabinets. The bistable relays contribute to energy savings and operational safety, retaining their switching state even when the power supply fails. Wiesemann & Theis provides a standard five-year warranty – a clear sign of quality and durability.

Future-proof 230V remote control for industry and buildings

The Wiesemann & Theis Web-IO 4.0 230V Relay 1xNO, 1xCO is a modern solution for anyone wishing to switch electrical loads safely and intelligently over networks. It combines traditional relay technology with modern IoT functionality, offering both efficiency and flexibility in a compact format. With support for OPC UA, MQTT, and REST, it is ideal for implementing forward-looking automation concepts.

Whether in industrial control, building automation, or home networking – this reliable relay solution from Wiesemann & Theis offers a stable foundation for precise remote control and monitoring applications in the 230V range.