Patent ID: 6173814
Filing Date: 2001-01-16
Classification: B66B,H04L

Abstract:
An elevator safety system comprising:an electronic safety controller in communication over a safety bus with a plurality of bus nodes;each said bus node receiving data from at least one sensor, wherein said safety controller further comprises a microprocessor assembly executing a safety program having multiple modes of operation including inspection and maintenance, normal operations, degraded operations, and emergency operations and wherein said safety bus further comprises:a dual redundant safety bus having a bus A and a bus B;said bus A and said bus B are physically independent from each other;each said bus node being in communication with both said bus A and bus B;wherein said safety program optionally communicates with each said bus node over either bus A or bus B or both, an elevator control unit in further communication with said electronic safety controller; anda drive and brake unit in even further communication with said electronic safety controller;wherein said microprocessor polls said bus nodes over said safety bus and processes said data received from said plurality of bus nodes and determines if an unsafe condition exists, and if so, said microprocessor sends an arrest signal to said drive and brake unit, and further sends a status signal to said elevator control.