Compaq AA-RHGWB-TE manual 11.1.3 TL881 and TL891 Rackmount Scalability

device and only works as a slave to the expansion unit. To create a multimodule rackmount system, there must be one expansion unit and at least one base unit. The expansion unit has to be the top module in the configuration.

The expansion unit works with either the TL881 or TL891 base unit.

•TL881 or TL891 base unit — includes library robotics, bar code reader, a removable 10-cartridge magazine, and one or two tape drives:

–TL881 — DLT 20/40 (TZ88N-AV) drives

–TL891 — DLT 35/70 (TZ89N-AV) drives

To participate in a MiniLibrary configuration, each base unit must be set up as a slave unit to pass control to the expansion unit. Once the expansion unit has control over the base unit, the expansion unit controls tape-cartridge movement between the magazines and tape drives.

_____________________ Note _____________________

You cannot mix TL881 and TL891 base units in a rackmount configuration as the tape drives use different formats.

•Data unit — This rackmount module contains a 16-cartridge magazine to provide additional capacity in a multi-module configuration. The data unit robotics works in conjunction with the robotics of the expansion unit and base units. It is under control of the expansion unit.

The data unit works with either the TL881 or TL891 base unit.

•Pass through mechanism — The pass-through mechanism is attached to the back of the expansion unit and each of the other modules and allows the transfer of tape cartridges between the various modules. It is controlled by the expansion unit.

For each base or data unit added to a configuration, the pass-through mechanism must be extended by seven inches (the height of each module). A seven-inch gap may be left between modules (providing there is sufficient space), but additional pass-through mechanism extensions must be used.

8.11.1.3TL881 and TL891 Rackmount Scalability

The rackmount version of the TL881 and TL891 MiniLibraries provides a scalable tape library system that you can configure for maximum performance, maximum capacity, or various combinations between the extremes.

Either library uses DLT IV tape cartridges but can also use DLT III or DLT IIIxt tape cartridges. Table 8–10 shows the capacity and performance of a

8–50Configuring a Shared SCSI Bus for Tape Drive Use