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Aperture Cover was physically in closed position. Interlock controls did not report Aperture Cover in closed position and prevented closing or opening Aperture Cover.
Recovery
Drive the Shutter back to high elevation. Gravity vector returned to normal condition when closing.
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With Aperture Cover switches in correct position the Safety Logic Fault could be reset and Aperture opened.
Drive Shutter down to 7° with Aperture Cover open.
Close the Aperture Cover when shutter at bottom position.