NR SAO-IEC-HD-62 ISSUE 4 PDF

PURPOSE

A Remote Interlocking Interface (formerly known as a Relay Interlocking Interface) subsystem (RII) is used to allow the incorporation of Route Relay Interlocking (RRI) signalled areas into the control area of an Integrated Electronic Control Centre (IECC). IECC communicates with interlockings using the Solid State Interlocking (SSI) protocol. RII uses the same protocol, but has access to the RRI indications and controls that were previously connected to the signaller's panel.

In most cases, the RRI will have been previously controlled directly by means of an entrance-exit (NX) panel and, hence, the controls and indications connected to RII will directly mirror the switches, lamps and buttons on the panel. Data for RII when used in this configuration is described in the SSI-Like Data Preparation Guide.

However in some instances, such as the Rock Ferry RRI forming part of the Merseyrail IECC area, the RRI may have been previously controlled by an NX panel via Electronic Route Selection Equipment (ERSE) and it may be decided to replace the ERSE with a TDM link to RII. The interface between RII and the RRI therefore closely resembles that between the ERSE and the RRI, and certain functions previously carried out by the ERSE must now be performed by means of RII data. This guide describes the preparation of the data for this configuration and outlines the principles to be adopted in implementing the RII-RRI interface

Although in theory this guide is equally applicable to the functionally similar Interface Processor (IFP), reference is only made to RII. The ERSE replacement has not been and will not be implemented with an IFP.