Patent ID: 7765033

Claim:
A method for a controller to control devices associated with a monitored space, said method comprising: defining a plurality of states of the controller controlling a controlled device associated with the monitored space; at an initial state, receiving an event indicating a possible presence of a subject within the monitored space; changing from the initial state in which the controlled device is de-energized to a first state in which the controlled device is energized in the first state and in response to the received event, said first state indicating that the subject can provisionally be in the monitored space; while in the first state: initiating an event timer set to expire after a first delay; resetting the event timer in response to receiving a signal indicating a detection one or more additional events before the expiration of the event timer thereby remaining in the first state; upon expiration of the event timer, changing from the first state to a second state; while in the second state: issuing a query challenge; responsive to the issued query challenge, detecting a query response signal; responsive to the query challenge, changing from the second state to the first state and resetting the event timer when the query response signal indicates the subject may still provisionally be in the monitored space; and responsive to the query challenge, changing from the second state to the initial state in which the controlled device is de-energized when the query response signal fails to indicate the subject responded to the query challenge.