The track voltage to the track section in front of the signal is directed via the BM1. If the signal is at ‘Stop’, the BM1 generates an asymmetry in the otherwise symmetrical, digital voltage. This is detected by Gold and Silver decoders as well as the new 10231-02 Standard. The result is a gentle braking of the train until it comes to a halt, optionally with the set braking delay or distance. If a train approaches from the opposite direction, it simply continues as the detection of the asymmetry is direction-dependent (i. e. the decoder detects, depending on the direction of travel, whether the asymmetry makes the digital voltage more ‘positive’ or ‘negative’). If the signal changes to ‘Clear’, the BM1 is bridged by the signal switch and the train accelerates at the speed set in the decoder.