9710 (StorageTek) Addendum for NonStop Servers

Addendum to the StorageTek 9710 for the Tandem Environment
The DLT Drive FRU in the 9710 Automated Cartridge Subsystem
5-9
5.10 Back-End Board (3216 Only)
The back-end board (BEB) translates fiber-optic signals from the
3216 controller into small computer system interface (SCSI)
commands and information for the tape drive FRU. A cage-like
sheet-metal enclosure houses the BEB and plugs into a 50-pin SCSI
port on the 9710 ACS patch panel. The BEB enclosure is visible
only when the door panel on the rear of the 9710 Automated
Cartridge Subsystem is removed. For information on connecting
the cables to the subsystem, see “Connecting the 9710 ASC Tape
Cartridge Subsystem to the Tandem Host”.
One BEB can serve two drive FRUs. If two drive FRUs are to be
connected, a daisy-chain cable links the first drive’s SCSI port on
the 9710 ACS patch panel to the second drive’s port on the patch
panel.
The BEB contains four light-emitting diodes (LEDs). Two LEDs
are external (easily viewed at the back of the BEB cage) and two
smaller LEDs are mounted internally on the circuit board of the
BEB. The internal LEDs are used by customer engineers trained by
Compaq. Customers do not need to use the internal LEDs to
troubleshoot the BEB.
All BEB LEDs are visible if the rear panel of the 9710 Automated
Cartridge Subsystem is removed. For a description of the BEB
LEDs, see the topic “Replacing a BEB”. For BEB problem solving
using these LEDs, see “Troubleshooting a BEB”.
5.11 Fiber-Optic Cable
A duplex fiber-optic cable connects the 3216 BIC to the BEB at the
rear of the T/16 5155 DLTtape Subsystem. Cable lengths can
range from 10 meters (33 feet, the default length) to 2 kilometers
(1.2 miles). Compaq provides fiber optic cable lengths up to 500
meters. For longer lengths see cable specifications (See Table 5-6).