The Beckhoff KL3351 Bus Terminal is a dedicated analog input module tailored for the acquisition of measurement bridge signals, particularly those generated by strain gauges and load cells. With its specialised design for full-bridge connections, the KL3351 enables direct integration of mechanical sensing devices into Beckhoff’s modular Bus Terminal I/O system, delivering precise and reliable measurement data to automation controllers.

The terminal features two inputs, supporting one complete resistive bridge circuit. This allows engineers to connect devices such as strain gauges, force transducers, load cells, or torque sensors without requiring external signal conditioning equipment. By supporting direct connection, the KL3351 simplifies installation, reduces wiring complexity, and lowers costs associated with additional hardware.

The measurement input range is tailored to the low-level signals typical of bridge sensors. It supports a differential signal voltage (UD) of -16…+16 mV, configurable to match sensor requirements. The reference voltage (UREF) operates within a ±10 V range, ensuring compatibility with a broad variety of transducers. These ranges make the KL3351 well suited for precise measurement tasks in weighing technology, machine monitoring, and test systems.

With 16-bit resolution, the KL3351 provides fine-grained measurement capability, capturing even the smallest changes in mechanical signals. This level of precision ensures that subtle variations in load, force, or strain can be detected and analysed, contributing to process quality, safety, and performance monitoring.

The module’s robust input design enhances measurement reliability. It offers an input impedance greater than 200 kΩ for UREF and greater than 1 MΩ for UD, minimising loading effects on connected sensors and ensuring measurement stability. Additionally, the KL3351 provides a 5 V DC excitation voltage (UV) with up to 20 mA supply, enabling it to power many standard strain gauge bridges directly, further reducing the need for external components.

The KL3351 integrates seamlessly with Beckhoff’s K-bus system, receiving its electronic power supply through the bus. This modular approach allows engineers to combine the KL3351 with other digital, analog, or communication terminals to build customised and scalable I/O solutions. Clear diagnostic LEDs on the housing provide simple feedback on operating state, aiding commissioning and maintenance.

Practical applications for the KL3351 include industrial weighing systems, force and torque measurement, material testing, and structural monitoring. Whether used in packaging lines, manufacturing equipment, or laboratory test benches, it delivers precise and dependable acquisition of critical mechanical measurement data.

In summary, the Beckhoff KL3351 Bus Terminal is a specialised and high-precision analog input module for full-bridge measurement applications. With 16-bit resolution, configurable mV input ranges, high input impedance, and integrated sensor supply, it provides a powerful and reliable solution for integrating strain gauge and load cell signals into modern automation systems.