HP Compaq StorageWorks TL881 DLT Mini-Library User Manual
Page 96
Installation 3-27
To maintain safety compliance, use a power cord with a suitable rating that is
approved for the country in which the product is used. In the USA, cords must
be UL listed, in Canada, CSA certified, and in Europe use a Harmonized cord
marked
are available as part of the associated TLTL881 Country Kits (Ordered
separately.)
SCSI Interfaces
MiniLibrary Modules come with a differential Fast SCSI and one or two
DLT20/40 drive(s). FastSCSI is available as differential or single-ended, and
uses two parallel female high-density 68-pin D-Series connectors per bus. Fast
SCSI cables and terminators are secured to the connectors by jackscrews.
NOTE: Compaq strongly recommends that you use differential controllers and high-
quality SCSI cables to ensure the highest performance of your MiniLibrary. Bus errors
caused by excessive length or poor quality cables can significantly degrade performance
and reliability.
In the MiniLibrary Base Module, each drive is wired to an independent bus
with a pair of SCSI connectors. Because it can be used in free-standing
applications, the MiniLibrary Base Module has a pair of SCSI connectors for
that module’s library robotics. The library robotics SCSI interface should not
be connected when installed in a system with an Expansion Unit. The
Expansion Unit controls the library robotics for all of the modules in the
system. It has a single SCSI bus, with a pair of SCSI connectors, to enable a
host to control the library robotics.
Each of the drives in the system and the library robotics is a separate SCSI
device and is wired to a separate SCSI bus. Any of the separate buses may be
combined using a SCSI jumper cable, available from Compaq. If any two or
more devices are connected to the same SCSI bus, each must be assigned a
unique SCSI address. For information on assigning SCSI addresses, see the
section entitled Configuration.
NOTE: For reduced internal cable length the single-ended units have the robotics and
first drive daisy-chained internally.
NOTE: For best performance, no more than two TZ89 drives should be connected to a
single SCSI bus, because of the bandwidth limitations of the SCSI bus.
A terminator of the proper type (68-pin differential) must be installed on each
unused connector at the end of each bus, as explained below in the section
entitled Interface Cable and Terminator Installation. Figure 3-15 shows the
SCSI cable, connectors and bus terminator used on the module.