This standard specifies the Passenger Alarm System (PAS) fitted to the passenger carrying rolling stock: a) The system itself: clause 4; b) The functional requirements for an alarm triggered in the driving cab: clause 5. c) The communication channel between the driver and passengers or on-board staff: subclause 5.3; d) The dynamic analysis of the Passenger Alarm System: clause 6; e) The requirements for the degraded modes management: clause 7 f) The safety related requirements: clause 8; g) Requirements for the handle and handle area: clause 9. This standard is applicable to passenger trains, including Tram-Trains, High Speed Trains, metros with drivers and excluding Trams, metros without driver and historical vehicles. This standard is not covering the "call for aid" system for trains. NOTE existing Passenger Alarm Systems may require modification to work in conjunction with vehicles that comply with this standard.