Installing The Pbus Terminators - HP 27115A Installation Manual

Optical receive port
D
D
--------..
::::::::
~
;
Optical transmit port
FIbcr-optic cable,
fiber with white sleeve
Figure 2-3. Fiber-Optic Cable Connection
Installing the PBus
Installing the PBus terminators has only two rules:
Terminators
Note
1. Every PBus socket must have either a terminator or a PBus cable
connector attached.
2. The terminators must be reversed with respect to each other.
Since different disk drives have different socket arrangements, there are two
terminator installation-indicator LEDs on the disk drive control boards near the
PBus cable/terminator sockets. All of the indicators on the PBus must be off. If
any is on, remove one of the terminators, invert it and re-install it. Figure 2-4
shows the disk-drive controller board for a single disk-drive installation and the
first and last controller boards for a multiple disk-drive installation.
Be sure the disk-drive power is on when you verify the LEDS. If you install the
PBus terminators wrong, the
HP-FL
link will not work. See the disk drive
manuals for more detail.
The PBus terminators for a multiple-drive
installation.
single-drive installation.
These LEDs must
be off. If either is
on, remove one
terminator and
invert it.
If any of these LEDs is on, remove
one terminator and invert it.
Figure 2-4. The Disk Drive Controllers Board Terminator LEOs
Installation and Configuration 2-5