Method and apparatus for maintaining states of an operator panel and convenience input/output station of a dual library manager/dual accessor controller system in the event of a failure to one controller

摘要

A method and apparatus is disclosed for maintaining states of an operator interface, such as an operator panel and convenience input/output station, of a dual library manager/dual controller system in the event of a failure to one controller during an operation. The invention allows control of the operator panel and convenience input/output station status lights and the states themselves by more than one controller without reinitializing at a default condition by detecting a failure during an operation, switching control to a second accessor controller and establishing a correct state for the operator interface via the second accessor controller. A correct state for a station is established by first establishing a fake empty status for the station and then locking the station, if necessary.