KL2184 by Beckhoff

The KL2184 is a digital output terminal produced by Beckhoff for the KL Bus Terminals series. This model serves as a discrete power-switching element that distributes 24 V DC power to field devices such as relays, contactors, and signal lamps. Within a modular bus terminal system, it occupies one station width and converts the controller's bit pattern into four independent channels. This arrangement allows actuators to be driven directly through the bus coupler without separate wiring islands.

Field devices connect through a 1-wire interface, while the terminal communicates with the upstream controller through the internal backplane bus. Each channel is referenced to the system's nominal 24 V DC rail and can source up to 0.5 A, providing sufficient current for moderate solenoids or pilot valves. Internal solid-state drivers provide consistent switching for resistive, inductive, and lamp loads. The logic image occupies only 4 output bits in the cyclic process map, and the module provides a total of 4 outputs. Front-facing LEDs indicate the state of each channel, allowing operation to be checked directly at the terminal. Downstream protection diodes suppress inductive voltage spikes, and the logic circuitry prevents interference between adjacent channels.

Mechanical installation uses a snap-fit connection on a 35 mm DIN rail, maintaining a compact footprint inside control cabinets. The housing has an IP20 rating, which protects against finger contact with live components after the module is installed. Integrated electronics include reverse-voltage protection, helping prevent damage to the output stage if the supply polarity is connected incorrectly. A short-circuit-proof current limiter reduces output current when the load impedance falls below a safe level. These protective functions help preserve individual channel operation when resistive, inductive, and lamp loads are connected within the same control system. The compact terminal format also allows adjacent I/O modules to share the rail and backplane connection without requiring additional mounting hardware.