KL2622 by Beckhoff

The KL2622 is a two-channel switching terminal produced by Beckhoff for the KL Bus Terminals series. It occupies one slot on a standard I/O node and provides electrically isolated contacts that allow a controller to energize or de-energize external devices such as contactors, indicator lamps, or solenoid valves. In an automation cell, the terminal converts the binary state held in the PLC process image into physical relay action, providing deterministic on/off control directly from the fieldbus.

The terminal offers 2 independent outputs, each implemented as a mechanical relay. Every channel can handle mains potentials up to 230 V AC or extra-low-voltage circuits up to 30 V DC. Within these limits, a maximum load of 5 A per channel can be switched, so resistive heaters, motor contactor coils, or pilot lights can be driven without external amplifiers. Two output bits are mapped into the process image, allowing the PLC to write individual coil states while maintaining galvanic separation between the logic and load circuits. The relay design eliminates the leakage current associated with semiconductor outputs, making the module suitable for loads that must be completely disconnected while switched off.

An internal isolation path rated at 500 V separates the bus side from the power side, helping prevent ground loops when mixed signal levels share the same rack. The housing clips onto a 35 mm DIN rail and can be mounted in any direction because the installation position is variable. The enclosure has an IP20 protection rating, so the terminal should be installed inside a closed control cabinet that prevents exposure to moisture and conductive debris. Each channel uses a single-pole, normally open contact, ensuring that connected equipment is energized only when the PLC explicitly commands the relay to close.