A control assembly for holding a pivoted door in an open position and releasable to enable the door to swing to a closed position. The at least one crane component is configured as a secondary energy source for energy recovery. After executing the command, the engine modifies the content of the event memory in order to recognize the completion of the command execution. The system may also convey such messages to a more remote location such as a housekeeping office and the switch may be activated remotely. In some instances, a plurality of fins can extend from the damper, with at least one fin extending from an air inlet side of the damper and at least one fin extending from an air outlet side of the damper. The recording layer includes a mixture of squarylium metal chelate compounds having ligands of the same type as well as metals of two or more types as the central metal.