Internal Cabling Configuration; Bus Length Limitations; Physical Configuration; System Expansion - Compaq SW TL881 DLT Mini-Lib/1 Reference Manual

2-40 Compaq StorageWorks TL881/TL891 Family MiniLibrary System Reference Guide

Internal Cabling Configuration

Bus Length Limitations

Physical Configuration

System Expansion

Free-Standing MiniLibrary Base Modules
Conversion
The differential MiniLibrary system is wired in an independent-bus SCSI
configuration; the robotics and each of the drives has its own SCSI bus. SCSI
jumpers are available for those applications requiring that some combination
of drives and robotics are daisy-chained to a single SCSI bus.
The single-ended table-top unit has the robotics and first DLT drive
daisy- chained internally to shorten the total internal cable length. The second
drive is on an independent bus.
The single-ended SCSI-2 bus is limited to 19 ft (6 m) in length; single-ended
fast SCSI-2 bus is limited to 10 ft (3 m) overall length. LVD SCSI bus length
is 39 ft (12 m). In contrast, differential SCSI-2 and fast SCSI-2 buses can be
up to 82 ft (25 m) long.
All modules in a MiniLibrary system must be mounted in a rack except for the
table top module version. When a system is ordered, all the modules are
supplied in a rack-mount configuration. Modules cannot be operated alone
except for the MiniLibrary Base Module, which can be converted to operate as
a free-standing 10-slot library.
A DLT MiniLibrary system can be expanded in capacity or performance or
both by adding or removing components. Associated with each component is a
section of the PTM. The MiniLibrary storage system firmware integrates the
robotics in the individual modules and the Expansion Unit PTM into a single
high-performance library robotics system.
You can add existing MiniLibrary Base Modules to your system by changing
firmware, resetting internal jumpers, removing the pass-through cover plate,
and in some cases converting from desktop to rackmount. These tasks should
be performed by qualified service personnel. Contact your technical support
representative for instructions.