In modern industry, process monitoring, and building technology, precise measurement and reliable control of analog signals are essential. The Web-IO 4.0 Analog 0-20mA from Wiesemann & Theis provides a universal solution for this purpose. It combines state-of-the-art network technology with high-resolution analog signal processing, merging precision measurement with IoT communication – ideal for Industry 4.0 and Internet of Things (IoT) applications.

With two independently configurable channels that can function as inputs or outputs for 0/4-20mA signals, the device offers remarkable versatility. It is suitable for data acquisition, control systems, or direct actuation of analog devices. Through seamless integration with automation systems, modern cloud services, and data management environments, the Web-IO 4.0 Analog serves as a key building block in networked measurement infrastructures.

The device architecture emphasizes reliability and ease of use. In addition to automatic network communication via MQTT, REST API, or OPC UA, an intuitive web interface provides direct access to real-time data and configuration options. This combination makes it an excellent choice for both development environments and existing automation networks.

Flexible signal acquisition and precise output control

The Web-IO 4.0 Analog 0-20mA features two channels that can each be configured either as inputs or outputs. In input mode, they capture 0/4-20mA measurement signals from sensors such as temperature, pressure, humidity, or flow transmitters. In output mode, they generate precisely controlled current signals to regulate external actuators, such as valves, controllers, or frequency converters.

Thanks to digital calibration and high-resolution conversion technology, the device provides highly accurate analog-to-digital and digital-to-analog signal processing. Distance transmission is also possible through the Box2Box function: an analog signal can be sent over the network directly to another Web-IO device, effectively creating a “virtual 20mA line” over Ethernet that transcends physical cable limitations.

User-friendly web interface and network access

With its clearly structured, browser-based interface, the device enables intuitive operation. Users can monitor measured values in real time via laptop, tablet, or smartphone. In addition to numerical displays, graphical trend visualizations are available – ideal for long-term measurements and trend analysis.

Control of 20mA outputs can be performed manually through input fields or via programmed interfaces. Developers can access channel data using HTTP requests, AJAX, or the REST API. The web interface is bilingual (German/English) and allows secure remote management in cloud-based environments.

Integration into IoT and cloud systems

The Web-IO 4.0 Analog supports modern communication standards, allowing direct integration with IoT platforms without additional gateways. Using MQTT, measured values can be transmitted directly to cloud services. OPC UA ensures compatibility with industrial automation systems, while the REST API provides accessible integration for web-based applications.

The device also supports classic IT structures with interfaces such as SNMP, Modbus TCP, and Syslog, ensuring smooth networking and monitoring. Additionally, the W&T Cloud enables global access and centralized storage of all measurement data, allowing users to analyze historical trends, generate automated reports, and manage alarms worldwide.

Alarm and reporting functions for analog signals

Up to 12 alarms can be configured to monitor defined thresholds – for example, when certain measurement values are exceeded or fall below limits. When a threshold is reached, the device can automatically execute actions such as:

• Sending an email notification with measurement values
• Triggering an SNMP trap in a network management system
• Automatically switching analog outputs
• Executing HTTP requests to external systems or cloud services

These notification features ensure rapid response times and continuous process oversight – particularly valuable in industrial applications with critical parameters. As a result, the Web-IO can be used not only for measurement but also for full process supervision.

Data logging and analysis with integrated logger

An integrated data logger records measured values over extended periods. The storage duration, depending on the logging interval (15 seconds to 60 minutes), can range from 150 days to 99 years. Data exports can be performed automatically or manually as Excel files, via FTP, or as email attachments. All recorded data is timestamped with high precision using the internal battery-backed real-time clock.

Synchronization with a time server (NTP) ensures accurate timestamps for all stored records. This is particularly valuable for audits, maintenance routines, and quality assurance processes in accordance with ISO standards.

Versatile application areas

• Process monitoring: capturing and visualizing temperature, pressure, or fill-level signals.
• Machine data acquisition (MDA): real-time tracking of production parameters.
• Remote monitoring: online collection and transmission of analog sensor data from remote sites.
• Building automation: control of heating, ventilation, or air conditioning systems with analog setpoints.
• Environmental monitoring: logging and analyzing physical environmental parameters such as humidity or light intensity.

Flexible power supply and industrial compliance

The device can be powered via Power-over-Ethernet (PoE) or an external 12–24V DC supply, offering flexibility for varying installation environments. It complies with key industry standards for electromagnetic compatibility (EN 61000-6-2) and meets emission requirements in accordance with EN 55032 Class B.

Reliability and stability in continuous operation

With its robust design and high-quality electronic components, the Web-IO 4.0 Analog is designed for continuous operation. DIN rail mounting ensures simple and secure integration into control panels and industrial environments. Wiesemann & Theis provides a five-year warranty, highlighting the system’s exceptional reliability and long-term durability.

Intelligent analog signal technology for industry and IoT

The Wiesemann & Theis Web-IO 4.0 Analog 0-20mA offers a modern solution for the precise acquisition, transmission, and control of 0/4-20mA signals. With configurable inputs and outputs, a powerful data logger, cloud connectivity, and extensive protocol support, it serves as a versatile tool for developers, technicians, and system integrators.

Whether for process monitoring, machine data acquisition, remote supervision, or building automation – this device bridges classical measurement technology with modern network communication, setting new benchmarks in analog signal processing.