File transitions are identified that are to be tracked and at least one element of metadata is generated that characterizes each identified file transition to be tracked. In the compound-split mode the two planetary units are joined together at two connections, creating two compound member branches and two single member branches. The core accommodates the coil, and has a core element which is arranged between permanent magnets and flanks of the core. When the data signal is a square wave clock signal, a duty cycle distortion caused by the delay lines passing the un-inverted signal is cancelled by a duty cycle distortion caused by the delay lines passing the inverted signal.