The Beckhoff KL3404 is a 4-channel analog input Bus Terminal designed for precise measurement of voltage signals within industrial automation systems. Supporting a signal range of –10…+10 V, it enables flexible acquisition of both positive and negative voltages, making it a versatile solution for process monitoring, control loops, and machine diagnostics.

Each of the four inputs is configured as a single-ended channel, allowing direct measurement of voltage signals from field devices such as sensors, transmitters, and controllers. With four inputs consolidated into one module, the KL3404 simplifies wiring, reduces hardware requirements, and saves valuable DIN rail space compared to deploying multiple single-channel devices.

The terminal provides a resolution of 12 bits across the full ±10 V range, delivering fine signal granularity. For unipolar 0…10 V measurements, it operates at an effective 11-bit resolution. This high level of precision ensures smooth and accurate data capture, while a typical measurement uncertainty of less than ±0.3% relative to full scale guarantees reliable results even in demanding applications. Such accuracy makes the KL3404 well suited for tasks where process stability and product quality depend on precise measurement, such as dosing systems, closed-loop regulation, or performance monitoring.

Speed is another strength of the KL3404. With a conversion time of approximately 2 ms per channel, the terminal supports near real-time acquisition of analog signals. This responsiveness is valuable in applications with fast-changing process variables, enabling timely feedback to the control system and supporting dynamic system adjustments.

To maintain signal integrity, the module features a high internal resistance greater than 130 kΩ. This ensures that the measurement circuit does not impose a load on the signal source, preserving accuracy when working with sensitive or low-power devices.

Electrical safety and operational stability are reinforced through 500 V isolation between the K-bus and signal voltage. This isolation protects the control system from electrical interference and prevents cross-coupling between channels, making the terminal dependable in environments where noise or mixed-signal levels are present.

As part of the Beckhoff Bus Terminal family, the KL3404 integrates seamlessly into modular I/O systems. Power is supplied via the K-bus, eliminating the need for separate wiring, while configuration and operation are managed through Beckhoff controllers and TwinCAT software. Its compact design and modular approach make it an efficient and scalable choice for modern automation systems.

In summary, the Beckhoff KL3404 is a precise and robust analog input terminal offering four single-ended ±10 V channels. With 12-bit resolution, rapid 2 ms conversion time, high internal resistance, and 500 V electrical isolation, it ensures reliable and accurate voltage measurement for a wide range of applications. Whether used in process control, machine monitoring, or data acquisition, the KL3404 provides the accuracy, flexibility, and safety required in advanced automation environments.