scope:

With the exception of Control Centre Identity numbers, this document is limited to recording information on SSI software and hardware that is (or was) in use on Railtrack infrastructure. Information at scheme category level is recorded, but, with minor exceptions, no scheme specific information is recorded. Information is limited to that required by SSI signalling scheme designers, testers and maintainers, and does not include the programs held in Panel Multiplexers, Train Describers, IECC, RETBs or other non-SSI systems that may be connected to SSI equipment.

Other than the ISSR, all items of a procedural nature, although referred to, are generally laid down in other procedural documentation, but any instructions given in this document are mandatory for all work affecting the configuration of SSI installations.

Purpose

To record information for the use of SSI signalling scheme designers, testers and maintainers on SSI program and data requirements, program issues, hardware modification states, their compatibility, equipment labelling, issued Control Centre Identity numbers and other related subjects.