ELECTRONIC INTERLOCKING TO BE TRIED IN JAPAN
Ikumasa Okumura · Railway gazette international · 1980
Early in 1981, the interlocking at Ishiuchi on the Joetsu Line of Japanese National Railways will be performed by computers, working in parallel with a conventional relay interlocking so as to check the integrity of the new technology under field conditions. System design avoids the need for a large number of programs by aggregating non-vital tasks, while reliability and safety are assured by two-out-of-three voting in a triple-redundant system. In addition, fail-safe fault detecting functions watch for component malfunction and shut down the subsystem affected, thus protecting overall safety.