scope:

This document is Issue Four. Section 9 contains advance information on some current development activities and their impact, which are not yet included in SSI8150. Separate Appendix NR/GN/SIG/17901/A is drawn from other sources.

It is intended for the information of users of installed SSI systems, and does not cover those elements of SSI used with the Design Workstation and On-Site Simulation systems, nor those activities relating to data preparers and scheme designers.

This document provides guidance on the use of the following equipment:

Panel Processor Modules

Interlocking and Diagnostic Multiprocessor Modules

Memory Modules

Data Link Modules

Long Distance Terminals

Signal Modules

Points Modules

Should there be any disagreement between this document and the SSI Applications Manual, the information in the SSI Applications Manual is to be taken as definitive.

Purpose

This document is a guide to the configuration of SSI Hardware and Software, based mostly upon information contained in the SSI Applications Manual, the contents of which are stated in NR/L2/SIG/17002 , and in particular upon the SSI Software Record SSI8150 . It describes through reference the various Categories of SSI system, and the permitted combinations of hardware and software in each Category. Means of identifying each Category and their defining features are described, together with upgrade paths and their advantages. It also describes SSI emulators that are used to replace SSI central interlockings.

The separate Appendix NR/GN/SIG/17901/A lists the Category of each Central Interlocking currently installed on Network Rail infrastructure.