Controller Card; Ssa Loops And Links - IBM 7133 D40 Service Manual

Controller Card

The controller card of the 7133 Model D40 or Model T40:
v Monitors itself. If it detects a problem, the controller card can generate an SSA error
message through the disk drive modules.
v Monitors the ambient air temperature. If the temperature is too high, the controller
card can:
– Increase the speed of the fans.
– Generate an SSA error message through the disk drive modules.
– Shut down the 7133, if necessary.
v Monitors the status of the fans. If a problem occurs with the fans, the controller card
can:
– Control the speed of the fans. For example, if one fan fails, the controller card
increases the speed of the other two fans to increase the cooling.
– Generate an SSA error message through the disk drive modules.
– Shut down the 7133, if necessary.
v Monitors the status of the power supply assemblies. If a power supply assembly fails,
the controller card can generate an SSA error message through the disk drive
modules.
v Monitors the Remote Power On feature (if installed) through the power supply
assembly that is in position 1.
v Monitors and controls the bypass cards.
v Monitors and controls the operator panel.
v Provides support for SCSI Enclosure Services (SES).

SSA Loops and Links

The disk drive modules of the 7133 are connected through two or more SSA links to an
SSA attachment that is located in the using system. The disk drive modules, SSA links,
and SSA attachment are configured in loops. Each loop provides a data path that starts
at one connector of the SSA attachment and passes through a link (external SSA cable)
to the disk drive modules. The loop continues through the disk drive modules, then
returns through another link to a second connector on the SSA attachment.
At the back of the 7133 are four bypass cards each of which has a pair of SSA
connectors for the external cables. Each bypass card provides connections to the
backplane assemblies of the 7133. If a bypass card loses both of its external SSA
connections, it automatically reconfigures the SSA loop so that the loop remains
complete.
For full details about the operation and configuration of bypass cards, see "SSA Bypass
Cards" on page 41.
Chapter 1. Reference Information
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