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Overlapping Accessor Motions in an Automated Tape Library

IP.com Disclosure Number: IPCOM000109404D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 2 page(s) / 65K

Publishing Venue

IBM

Related People

Kishi, GT: AUTHOR

Abstract

This article describes the overlapping of accessor motions in an automated tape library (ATL) that allows the accessor to operate efficiently.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 53% of the total text.

Overlapping Accessor Motions in an Automated Tape Library

       This article describes the overlapping of accessor
motions in an automated tape library (ATL) that allows the accessor
to operate efficiently.

      An automated tape library consists of tape cartridge storage,
tape drives, and an accessor that moves tapes between the storage and
the drives.  In library operation, the accessor will be given a
series of commands to perform.  These include:
      Get a cartridge from a storage location
      Inventory a cartridge in a cell location

      This article focuses on an accessor that moves along a rail.
Cartridge storage is provided on both sides of the rail.  To get a
cartridge from a storage location, the accessor must perform the
following steps:
      Move arm clear of the storage
      Move down the rail to the goal position
      Reorient the arm to a picking position
      Read the cartridge label
      Pick the cartridge
      Get next command

      The first overlapped motion occurs when the arm is being moved
clear of the storage.  A test is made on the position of the arm.
When the arm has moved the minimum safe distance out of the storage
location, the accessor is started down the rail.  While the accessor
is moving down the rail, the arm is moved to the maximum safe
distance from the storage.  While the accessor continues to move down
the rail, the arm is reoriented to its picking position....