scope:

This standard is applicable to safety-related electronic systems (including sub-systems and equipment) for railway signalling applications. The scope of this standard, and its relationship with other CENELEC standards, are shown in Figure 1. This standard is intended to apply to all safety-related railway signalling systems/sub-system/equipment. However, the hazard analysis and risk assessment processes defined in EN 50126 and this standard are necessary for all railway signalling systems/sub-systems/equipment, in order to identify any safety requirements. If analysis reveals that no safety requirements exist (i.e.: that the situation is non-safetyrelated), and provided the conclusion is not revised as a consequence of later changes, this safety standard ceases to be applicable. This standard applies to the specification, design, construction, installation, acceptance, operation, maintenance and modification/extension phases of complete signalling systems, and also to individual sub-systems and equipment within the complete system. Annex C includes procedures relating to electronic hardware components. This standard applies to generic sub-systems and equipment (both application-independent and those intended for a particular class of application), and also to systems/sub-systems/equipment for specific applications.