scope:

Introduction

Each SSI Central Interlocking is equipped with two Panel Processors Modules. These modules each have a single processor, the "Panel Processor". The function of the Panel Processors in an SSI Central Interlocking is to provide an interface with the Panel Multiplex system which drives the indications on the Signalman's Panel and detects operation of push buttons and switches, and with Train Describer equipment. The Panel Processors are not part of the safety system and duplication is provided to achieve high availability. As with the Interlocking Processors themselves, the program in the Panel Processors is identical for all Panel applications, and the logic required to control the Panel indications and interpret push button and switch operations is stored in the processors' memory as tables of geographic data which are interpreted by the program.

See SSI8003-53 for the Panel Processor data requirements for Central Interlockings controlled by Integrated Electronic Control Centre (IECC) systems.

The purpose of this document is to describe the function of the geographic data and how to prepare it. A fundamental object of the SSI project has been that the task of data preparation should not require staff with experience of computer programming or of the actual software in the SSI Processors. Many of the features of the data are identical to those in the Interlocking Processor, which have been described in SSI8003-10, and these will not be repeated in this document, except to explain how they are applied in the Panel Processor.