In modern industrial facilities and complex building networks, precise relay control plays a decisive role in optimizing processes, ensuring operational safety, and managing energy efficiently. The Web‑IO 4.0 Digital 4x Relay Out from Wiesemann & Theis is a highly advanced solution that enables convenient control of four independent relay outputs over a TCP/IP Ethernet network. Three of these outputs are configured as potential‑free normally‑open contacts (NO), while the fourth is a potential‑free changeover contact (CO) – a design concept that guarantees flexibility for a wide range of switching requirements.

Thanks to its specially developed web interface, usable on both desktop systems and mobile devices, operators can monitor output statuses in real time and trigger switching operations as needed. Supporting modern network protocols such as OPC UA, MQTT, and REST API, the device forms the perfect bridge between traditional switching technology and the requirements of Industry 4.0 as well as the Internet of Things (IoT). It enables seamless integration into remote monitoring, automation, and control systems without complex hardware extensions.

The modular approach, combined with a compact form factor and DIN‑rail mounting capability, makes the Web‑IO 4.0 Digital a universally applicable tool for building automation, home automation, and industrial process control. Whether for lighting, access systems, barriers, or machinery – with a direct switching voltage up to 48 V (or higher voltages via coupling relays) and currents of up to 2 A at 24 V, a variety of electrical devices can be safely and reliably controlled.

With its innovative alarm function, up to 30 actions can be defined and automatically executed upon state changes – ranging from email notifications to SNMP alerts and direct control of other Web‑IO devices. The Box‑to‑Box function allows switching signals to be transferred across locations, enabling decentralized yet synchronous control of complex systems. The device impresses with high flexibility when integrating with third‑party systems and significantly increases operational transparency.

Technical Precision and Reliable Performance

The performance specifications of the Web‑IO 4.0 Digital 4x Relay Out are tailored precisely to industrial operating conditions. Each of the four outputs is designed to ensure secure switching even in demanding environments. The three potential‑free NO contacts provide a reliable solution for pure switching‑on operations, while the CO contact offers flexible switching capability, for instance in redundantly secured control paths.

All outputs are optimized for direct switching voltages up to 48 V, with higher voltages—such as 110 V or 230 V—switchable via suitable coupling relays. Current handling capacity is up to 2 A (24 V) or 0.5 A (48 V). These specifications make the device suitable for both sensitive control systems and robust power applications.

Modern Communication Protocols for Industry 4.0

In addition to standard HTTP and HTTPS protocols, the device supports advanced interfaces such as OPC UA, MQTT, and REST API. Developers value this variety, as it allows the Web‑IO to integrate easily into nearly any IoT platform or automation software. With SNMP support (versions V1, V2, V3), the device can also be simply integrated into existing network monitoring structures. Additional interfaces including Modbus TCP, OPC DA, Syslog, and Sensobase integration via ODBC complete the feature set.

The device supports TCP and UDP connections in both client and server modes. FTP support enables long‑term logging of switching operations and subsequent data analysis.

High‑Level Alarm and Notification Functions

The integrated alarm management can be configured so that predefined actions are executed immediately when an event changes. Email alerts provide fast communication in critical scenarios, while SNMP traps enable automated network responses. Direct control of other Web‑IO devices within the network is also possible without additional hardware – a significant benefit for complex remote monitoring setups.

Data Storage and Precise Timestamping

The internal data logger ensures seamless recording of all switching activities for periods ranging from at least seven weeks to up to twenty years—depending on the set interval between 15 seconds and one hour. Export formats such as FTP transfer, Excel files, or email attachments make further processing straightforward. A battery‑buffered real‑time clock ensures that all operations are assigned precise timestamps and can be synchronized via a time server.

Flexible Power Supply and Standards Compliance

Power supply is possible via PoE (Power over Ethernet) with phantom power or through an external supply unit (12–48 V DC). This makes the device suitable for deployment in modern PoE‑enabled networks as well as traditional setups. Compliance with standards such as EN 61000‑6‑2 and EN 55032:2015 + A1 Class B underscores the system’s robust construction and high immunity to interference.

Durability and Robust Design

With a five‑year warranty and construction designed for continuous operation, the Web‑IO 4.0 Digital 4x Relay Out is a sustainable investment. DIN‑rail mounting and rugged components make it an ideal tool for production facilities, building control elements, or complex IoT projects.

A Versatile Control and Automation Module

Whether in building automation, home automation, or industrial process chains, the Web‑IO 4.0 Digital from Wiesemann & Theis is a future‑proof solution for precise relay control, flexible alarm functionality, and seamless integration into Industry 4.0 and IoT infrastructures. It is suitable for controlling lighting, heating systems, barriers, or complex machinery processes and delivers long‑term reliability, safety, and versatility.