CLC/TC 9X/WG 28 - Survey Group on a cross functional standard on software

1.1 This document specifies the process and technical requirements for the development of software for programmable electronic systems for use in: - control, command for signalling applications, - applications on-board of rolling stock. This document is not intended to be applied in the area of electric traction power supply (fixed installations) or for power supply and control of conventional applications, e.g. station power supply for offices, shops. These applications are typically covered by standards for energy distribution and/or non-railway sectors and/or local legal frameworks. 1.2 This document 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 document applies to software as per subclause 1.1 of this document 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 document also addresses the use of pre-existing software (as defined in 3.1.16) and tools. Such software can 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 Intentionally left blank 1.7 This document 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 Intentionally left blank 1.9 This document is not intended to be retrospective. It therefore applies primarily to new developments and only applies in its entirety to existing systems if these are subjected to major modifications. For minor changes, only 9.2 applies. However, application of this document during upgrades and maintenance of existing software is advisable. 1.10 For the development of User Programmable Integrated Circuits (e.g. field programmable gate arrays (FPGA) and complex programmable logic devices (CPLD)) guidance is provided in EN 50129:2018 Annex F for safety related functions and in EN 50155:2017 for non-safety related functions. Software running on softcore processors of User Programmable Integrated Circuits is within the scope of this document.