This European Standard specifies the general requirements for the installation of the passenger alarm subsystem. The passenger alarm subsystem is fitted to passenger trains used on national networks including trans-European high-speed and conventional interoperable rail systems. The passenger alarm subsystem includes the passenger emergency brake system. NOTE The passenger emergency brake is sometimes shortened to emergency brake (esp. German: Notbremse) or passenger alarm (esp. English: alarm, French: alarme). The passenger emergency brake can be operated in case of emergency brake demand by passengers or personnel in the train in order to stop the train.