NR SSI8003-91 ISSUE 2 PDF

Purpose and Contents

The purpose of this document is to provide a formal specification for the data constructs which may be used within Interlocking and Panel Processor data. Such a specification is intended to fulfil three purposes:

(a) It supplements the Software Requirements Specification. The Interlocking and Panel Processor software must be capable of correctly processing any data which conforms with the syntax specification.

(b) It specifies the requirements for the Interlocking and Panel Processor data compilers. The compilers must be capable of compiling any data which conforms to the syntax specification, and must detect any data which does not conform and generate meaningful error messages.

(c) It acts as a reference document for staff engaged in data preparation, to assist in the design of non-standard and complex data for which examples are not available in the data preparation guide and its supplements.

This document's role is to fulfil purpose (c), whereas British Rail Research (now AEA Technology Rail) document ELS-DOC-4416 is used to fulfil purposes (a) and (b). In order to maintain strict compliance between the two documents, the Tables in each issue of SSI8003-91 are based on a direct copy of those in the current issue (at present issue C) of ELS-DOC- 4416 (the only changes are the details added for addresses 1260 to 127F in Table 14). The syntax shown matches that which is used by compilers in SSI Design Workstation programs GS/SI8310 & GS/SI8320 Issue/Revision 8A. The additional data types and syntax associated with the SSI Axle Counter Module have been added in preparation for their future introduction.