Patent ID: 7501930

Claim:
A control system for a lock of a door movably disposed within a frame, the lock having a latch engageable with the frame to releasably secure the door to the frame, the door having an interior handle operatively connected with the latch and an exterior handle operatively connectable with the latch, the control system comprising: a connective mechanism configured to releasably connect the exterior handle with the latch; an input device configured to generate an unlock signal; a controller coupled with the input device and configured to operate the connective mechanism such that the mechanism connects the exterior handle with the latch, the controller being selectively operable in a first, standard mode in which the controller operates the mechanism when the controller receives the unlock signal and a second, lockdown mode in which the controller does not operate the mechanism when the controller receives the unlock signal; and a lockdown-input device coupled with the controller and configured to generate a lockdown signal, the controller being configured to switch from the standard mode to the lockdown mode when the controller has received the lockdown signal from the lockdown device, wherein the controller is configured to switch from the lockdown mode to the standard mode when the door is displaced with respect to the frame, and wherein the input device is further configured to generate a master unlock signal when the input device receives a predetermined master-user input and the controller is configured to operate the connective mechanism such that the mechanism connects the exterior handle with the latch when the controller receives the master unlock signal when in the lockdown mode and receipt of the lockdown signal within a predetermined time interval subsequent to displacement of the door after the controller has received the master unlock signal in the lockdown mode causes the controller to remain in the lockdown mode.