KL4112 by Beckhoff

The KL4112 is an analog terminal from Beckhoff that belongs to the KL Analog Output Modules series and is intended for DIN-rail-mounted control cabinets. Acting as a current interface between a Bus Coupler or EtherCAT Coupler and field actuators, it converts digital process data from the controller into precisely regulated milliampere signals. This function lets a PLC drive valves, positioners, or similar devices that use standardized current loops, integrating them directly into decentralized I/O stations without the need for separate signal converters.

For each channel, the terminal provides a default resolution of 15 bits, giving 32,768 discrete steps across the output span so fine setpoints can be applied to proportional equipment. The programmable range extends from 0 mA to 20 mA, supporting common 4-20 mA and 0-20 mA loops. Internal circuitry maintains the output as long as the connected load remains less than 500 ?. Process data are exchanged over the K-bus in blocks of 2 × 16 bits, allowing both channels to be updated simultaneously with status information in a single cycle. A built-in watchdog resets both outputs to a safe state if no new command is received within 100 ms, preventing unintended actuator drift.

The terminal draws its logic and driver power through the backplane at 24 VDC through power contacts, eliminating separate field wiring and reducing panel space. It snaps onto a 35 mm mounting rail, matching the mechanical arrangement used by other Beckhoff slice modules so mixed-signal stations can be assembled end to end. The IP20 enclosure protects against accidental contact with internal components while permitting installation in protected control cabinets. The unit operates from 0 °C to +55 °C, and its two independent outputs remain accurate when the ambient temperature fluctuates within this range. Long-term storage is permitted from -25 °C to +85 °C.