A system and method for improving the efficiency with which data communications are passed through a protocol stack. Each well extends between the two surfaces of the holding plate, and has an aspect ratio of greater than 5:1, and a diameter less than approximately 500 microns. The relay controller is configured to open or close the first relay or the second relay in response to a power requirement indication. Among the optical discs which have been taken, a target optical disc opposite the slit of the disc control plate passes through the slit, and the other optical discs stop while abutting against the disc control plate.