1.1 This European Standard specifies the process and technical requirements for the development of software for programmable electronic systems for use in control, command for signaling applications and any on-board of rolling stock. This European Standard is not intended to be applied in the area of electric traction power supply (fixed installation) or for power supply and control of conventional applications, e.g. station power supply for offices, shops etc. These applications are covered typically by standards for energy distribution and/or non-railway sectors and/or local legal frameworks. For railway related fixed installations (electric traction power control and supply) the EN 50562 is applicable. 1.2 This European Standard is applicable exclusively to software and the interaction between software and the system of which it is part. 1.3 Intentionally left blank 1.4 This European Standard applies to all software used in railway systems, including - application programming, - operating systems, - support tools, - firmware. Application programming comprises high level programming, low level programming and special purpose programming (for example: Programmable logic controller ladder logic). 1.5 This European Standard also addresses the use of pre-existing software and tools. Such software may be used, if the specific requirements in 7.3.4.7 and 6.5.4.16 on pre-existing software and for tools in 6.7 are fulfilled. 1.6 Software developed according to any version of EN 50128 or EN 50657 will be considered as compliant and not subject to the requirements on pre-existing software. 1.7 This European Standard considers that modern application design often makes use of software that is suitable as a basis for various applications. Such software is then configured by application data for producing the executable software for the application. 1.8 Entry intentionally left empty. 1.9 This European Standard is not intended to be retrospective. It therefo ...