NR SSI8505B ISSUE 6 PDF

Introduction

This document defines the processes to be adopted for the management and handling of SSI geographic data and software throughout the data lifecycle, from scheme design through installation, commissioning, maintenance, and record keeping. It also specifies the procedures to be adopted for the programming of EPROMs in support of the above activities.

The aims of these processes are:

• To commission 100% correct data.

• To exercise adequate control of versions of SSI data and issues of associated programs.

• To provide an adequate level of recording and certification.

• To maintain complete and accurate records.

• To confirm that data and programs are correctly installed in the modules to which they relate.

The following Sections describe the various stages of the data process, and these shall be adhered to, as an essential part of meeting the above requirements.

At the heart of data version control is the Central Interlocking Status Record (CISR). A summary of CISR operation follows.

A new CISR is created each time new or changed data is passed on for checking or onto other parties or the installed associated data processing programs are changed. The CISR includes the following • information for each Central Interlocking:

• Scheme/Interlocking names and numbers

• Present and previous CISR serial numbers

• Date/time stamps of all data files

• Version/Sub-version Numbers and checksums of object code

• Issues of non scheme specific documents used such as SSI8003 and this document-the appropriate issue of the SSI Applications Manual Contents document may be given

• Issues of scheme specific documents used such as scheme plans and Control Tables

• Programs that will be used with the data in the target SSIs

• Versions of related systems such as other Central Interlockings (CIs) and IECC

A master print of the CISR is produced and this is then used to record why the data has been changed and who has prepared and checked the various areas of source data. This print then accompanies that version of data as far as it proceeds through the data checking, testing and commissioning process, with each stage being signed off on the CISR before the data passes on to the next stage. If data errors are found that result in further changes then a new CISR is produced to accompany that version of data as far as it gets through the process.

Once the data reaches the EPROM programming stage an Installed SSI Software Record (ISSR) has to be completed. This provides an on site record of the program issues, data versions and equipment modification states in the SSI CI cubicle, records the serial numbers of MMs that hold the above software, and records that all necessary Design Office checks on the Memory Modules (MMs) and cubicle have been completed.

The production and management of the CISR and ISSR are the responsibility of the Data Manager. Details of the use of the CISR and ISSR are given in Chapters C and D respectively.

This document is written specifically for schemes using MkII, MkALIII and MkWSIII Interlocking Cubicle equipment. For schemes using MkI equipment, these Sections shall be followed as far as possible. The main differences between MkI, MkII, MkALIII and MkWSIII are:

• In MkI MPMs and PPMs, data and main processor programs are held in a suite of EPROMs, and these EPROMs are held in the main body of the PPM or MPM.

• In MkII PPMs and MkII, MkIIA, MkALIII and MkWSIII MPMs, data and main processor programs are held in one EPROM for each set of data or program, and these EPROMs are held in a separate MM.