2. Interaction between rolling stock and control and signaling subsystems

2.1 Introduction

The rolling stock and control-command-signaling (CCS) subsystems are both complex, and there are many potential modes of coupling. This interaction must be mastered at all costs, as it guarantees traffic safety, particularly in terms of the signaling component's "separation" function, which prevents a train travelling ahead from overtaking another train on the same track (figure 8 ). The track is divided into sectors called blocks. This function involves detecting the train(s) on each block, and ensuring sufficient spacing to guarantee that it is impossible to overtake the preceding train at full speed.