scope:

PURPOSE

A Remote Interlocking Interface (formerly known as a Relay Interlocking Interface) subsystem (RII) or an Interface Processor (IFP) 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 and IFP use the same protocol, but have 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 (or IFP) when used in this configuration is prepared in a similar way to SSI data and is described in this guide.

However in some instances, 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 (Note. IFP has not been and will not be used as an ERSE replacement). Data for RII when used in this configuration is described in the complementary ERSE guide^[1].

RII and IFP perform the same function. RII supersedes IFP and, unlike IFP, uses the same hardware and software architecture as other IECC subsystems.

[1] IECC Data Preparation, IDPM 1502, Relay Interlocking Interface Reference, SAO-IEC-HD-60, Issue 4, 29 October 1999.