Can someone explain the meaning of this paragraph? The manufacturer elected to install a manually controlled monitoring function, in the form of pushbuttons located on both sides of the control panel, where pushing on either button serves to activate the monitoring mode. The pushbuttons resemble those used on existing SNCF systems. This control is linked with a time delay mechanism borrowed from Alstom’s Citadis model, established as the reference in terms of safety level, by virtue of the GAME principle mentioned above. This time delay authorizes holding the button down at most 15 s (13 s before triggering a buzzer and then 2 s until the emergency brake gets applied) or a release of at most 4 s (2 before the buzzer and another 2 before the emergency brake). I didn't understand quite well the 15 s and 4 s mechanisms... It's trying to explain dead man's switch, device to detect if the driver is not feeling well or drowsy.