IBM TotalStorage SAN140M, Installation And Service Manual

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SAN140M Installation and Service Manual 12
• An input filter and AC system harness (internal to the FRU) that
provides the wiring to connect the AC power connectors to the
power supplies (through the backplane).
Fan module
Three fan modules, each containing one system fan (three system fans
total), provide cooling for director FRUs, as well as redundancy for
continued operation if a fan fails.
A fan module can be replaced while the director is powered on and
operating, provided the module is replaced within ten minutes (after
which software powers off the director). An amber LED for each fan
module illuminates if one or more fans fail or rotate at insufficient
angular velocity.
SBAR assembly
The director is delivered with two SBAR assemblies. The active SBAR
is responsible for Fibre Channel frame transmission from any director
port to any other director port. Connections are established without
software intervention. The assembly accepts a connection request
from a port, determines if a connection can be established, and
establishes the connection if the destination port is available. The
assembly also stores busy, source connection, and error status for
each director port.
The backup SBAR takes over operation if the active assembly fails,
and provides the ability to maintain connectivity and data frame
transmission without interruption. Failover to the backup assembly is
transparent to attached devices.
Each SBAR assembly consists of a card and steel carriage that mounts
flush on the backplane. The carriage provides protection for the back
of the card, distributes cooling airflow, and assists in aligning the
assembly during installation. The rear of the carriage contains a green
LED that illuminates if the assembly is operational and active, and an
amber LED that illuminates if the assembly fails. Both LEDs are
turned off on an operational backup assembly. The amber LED blinks
if FRU beaconing is enabled.
Backplane
The backplane provides 48 VDC power distribution and connections
for all logic cards. The backplane is a nonconcurrent FRU. The
director must be powered off prior to FRU removal and replacement.