Traffic light control system and method

摘要

A traffic light control system comprising a plurality of controllers each for controlling a traffic light signal unit, one of the controllers being a master controller and the other or others slave controllers, wherein the master controller is operable to transmit to each slave controller the required signal state of its associated signal unit and each slave controller is operable to compare the actual signal state of its signal unit with its required state as defined by the last required state received from the master controller and activate a failure condition procedure in the event of a conflict between the actual and the required signal states.