The KSM-4 reversing module adjusts the polarity within the reversing loop depending on the position of the switch, ensuring that no short circuit occurs when crossing the separation point. Transition areas with integrated track occupancy detectors are arranged between the switch and the interior of the reversing loop. As soon as a train enters one of the two transition areas from the reversing loop, the switch is set for the train's exit, and the polarity within the reversing loop is adjusted.

The switch must be connected to the KSM-4 and is automatically set for the train's exit from the reversing loop. The KSM-4 has two switch inputs for connecting a button or a comparable circuit, allowing the switch to be operated externally. This way, a direction of travel within the reversing loop can be predetermined before entry.