Has the fail-safe system and its system the grade crossing control unit

摘要

PROBLEM TO BE SOLVED: To prevent an accident caused by the erroneous use stop operation of a railway crossing controller by providing a switch having a key and at least one or more switches having no keys, and making valid the operation of the switches having no keys only when the switch having a key is rotated up to a specified state. ;SOLUTION: An interface 3 operates a use stop key switch 1 and then recognizes the operation of an up use stop switch 2-1 or a down use stop switch 2-2 when it is operated. If the use stop key switch 1 is operated after the up use stop switch 2-1 or the down use stop switch 2-2 is operated, the interface 3 does not recognize the operation thereof. The interface 3 does not recognize the operation unless the switch is operated in a specified order. Thus, even if the use stop key switch 1 is operated, an accident caused by the erroneous operation thereof is prevented.;COPYRIGHT: (C)1999,JPO