Abstract: A method for requesting a closure of a track section and a closure revocation by way of a closure signal sent by a communication device, having a monitor on the track section, to a signal box and by way of a sent closure revocation signal. In order to render such a method more secure, the sent signals are secured by way of a secure computer module that can be optically coupled to the monitor, and a signal box is used which is expanded in such a way that the signal box detects the sent and secured signals and sends confirmation signals to the secure computer module. There is also provided an assembly with a communication device having a monitor on a track section.

Abstract: An actuator has at least one mechanical activation device, to which at least one activation cable for activating field elements in the external system of the actuator is mounted. In order to implement such an actuator in a low-maintenance fashion, the activation cable is guided to a mechanical-electronic converter from which at least one electrical line leads to electronic systems of the field elements of the external system of the actuator.