scope:

Introduction

SSI has been designed to operate with an entrance/exit push button Panel outwardly identical to those used with conventional relay Interlockings and meeting the requirements of GK/RT0025 (ref. 1).

The PPMs in the CI contain geographic data, carry out all indication meshing and button matching and are linked to the PMUXs in the Panel.

SSI can alternatively be linked to an IECC. The IECC employs Signalman's VDU type workstations, includes TD and ARS and carries out the indication and button processing functions normally done by the SSI PPMs. Thus the PPMs have a different non-data driven fixed program and purely act as a communication port between the IECC and the SSI Interlocking MPMs. For the design of, and data preparation for, the IECC system itself, the appropriate IECC documentation must be referred to.