HP SW TL881 DLT Mini-Lib/1 Compaq StorageWorks TL881/TL891 Family MiniLibrary - Page 25

1-8 Compaq StorageWorks TL881/TL891 Family MiniLibrary System Reference Guide Physical Configuration The Expansion Unit must be mounted at the top of the stack, which places its control panel at a convenient height. The control panels of the MiniLibrary Base Modules and Data Units are of secondary importance, as they serve mainly to help localize system failures. When installed, the motor drive assembly of the PTM is directly behind the Expansion Unit. MiniLibrary Base Modules can be installed anywhere below the Expansion Unit, in any order. There can be a slight performance advantage in making the MiniLibrary Base Modules contiguous, but gaps are permitted. The size of a gap is limited by the fact that the same number of 7- inch track sections must bridge each gap. For safety, available cover plates should be installed on all PTM sections that are not connected to MiniLibrary modules. The Expansion Unit senses the position of each module during initialization at power-up. Even if there are gaps between modules, the system will operate correctly. If you plan to leave gaps between modules, be sure to order additional PTM track segments and cover plates equal to the length of the gap. System Expansion A MiniLibrary system can be expanded in capacity and performance by adding or removing TL881/TL891/TL891DLX modules. Associated with the Expansion Unit and each MiniLibrary Base Module is a section of the PTM. System firmware integrates all of the robotics of these system modules with that of the PTM into a single high-performance library robotics system. Features There are a number of important external features to note about the Expansion Unit, the MiniLibrary Base Module and the Data Unit. See Figures 1-4 through 1-7 to locate the features described in the following sections.