User`s guide

remains powered by the ac power entry controller B. As shown in Figure 1–3, this
configuration provides complete power redundancy to the shelf’s devices.
The ac power entry controller A provides power to the four power supply SBBs
on power supply bus A. This is the minimum power configuration (4+0) for the
system. The power supply SBB located at the top of power supply bus B provides
power for 4+1 redundancy.
For 4+4 redundancy, the ac power entry controller B provides power to the
four power supply SBBs on power supply bus B. See Chapter 3 for additional
information on power configurations.
Figure 1–3 SW300 Power Configuration
POWER
SUPPLY
BUS A
POWER
SUPPLY
BUS B
AC POWER
ENTRY
CONTROLLER A
AC POWER
ENTRY
CONTROLLER B
PRIMARY AC
POWER SOURCE
AUXILIARY AC
POWER SOURCE
CXO-4306A-MC
POWER SUPPLY
BUS A
(USED WITH 4+1
REDUNDANCY)
SHELF 4
SHELF 3
SHELF 2
SHELF 1
CONTROLLERs
AND EMUs
1.3.2 The High-Availability Storage Subsystem Fault Bus
The HS-series controllers use the StorageWorks high-availability storage
subsystem fault bus to monitor certain fault conditions in the subsystem’s
shelves and enclosure. The fault bus, which is not a FRU, offers the following
features:
• Notification when a device is physically removed from or inserted into the
storage subsystem
• Notification of a failure associated with a device shelf and enclosure (for
example, a shelf blower)
• Visual indication of bus/device status, facilitating fault isolation by the user
The high-availability storage subsystem fault bus consists of four signals added
to each SCSI device port as described in the StorageWorks Solutions High-
Availability Storage Subsystem Fault Bus OEM Engineering Specification. The
controller uses the fault bus signals in the manner described in the specification.
Introduction to the SW300 Enclosure 1–5