PRACTICAL USE OF COMPUTERIZED INTERLOCKING SYSTEM 'SMILE' IN JNR.

The Japanese National Railways (JNR) has been engaged in the development of a computerized interlocking system for railway signaling for several years. The first practical model of such a system was put into operation in March, 1985, at Higashi-Kanagawa Station on a commuter line with very heavy traffic. This commputerized interlocking system is called Safe Multiprocessor system for Interlocking Equipment or SMILE for short. It controls signals and switches distributed in the station yard and sets routes for train operation. SMILE is a fail-safe and fault-tolerant system utilizing a general-purpose microcomputer as its principal component. In addition to the interlocking function, this system has various automated functions such as automatic route control, and thus it is superior to the conventional relay interlocking system in terms of workability, maintainability, economy and ease of providing interface with other electronic systems.