Installation guide

5. The SSA connectors at the back of the 7133 are mounted on four bypass cards
(also known as SNBC cards). These bypass cards can operate in Automatic mode
or in Forced Inline mode. The default setting is for Automatic mode. You can put a
bypass card into Forced Inline mode by changing the positions of the two jumpers
on the card.
Forced Inline mode is used to disable the switching ability of selected bypass cards
in particular types of subsystem configuration. The types of configuration that might
require Forced Inline mode are those in which:
v Two 7133s are connected to each other. In this type of configuration, Forced
Inline mode removes the risk that a fault condition might break the connection
between the two 7133s. The second example in “Higher-Availability
Configurations” on page 33 shows a typical configuration of this type.
v The disk drive modules in one 7133 are not all connected to the same SSA loop.
In this type of configuration, Forced Inline mode removes the risk that a fault
condition might cause the disk drive modules of different loops to be connected
to each other.
Refer to the customer’s subsystem configuration information, and check whether all
four bypass cards are to remain in Automatic mode.
Note: The cards need not all be in the same mode.
If the cards are to remain in Automatic mode, take no further action. Go to step 6.
If any card is to be changed to Forced Inline mode, go to “Appendix B. Changing
the Jumpers on a Bypass Card” on page 39, and make the change. When you have
finished, return here, and go to step 6.
6. Refer to the customer’s subsystem configuration information, and verify that the
rules for SSA configurations have been observed (see Note 4a on page 9). When
you have verified the information, go to “Connecting SSA Cables to the 7133 Model
T40” on page 12 or to “Installing and Connecting Advanced SSA Optical Extenders
to the 7133 Model T40” on page 14, as required by the configuration information.
Note: If the subsystem configuration information is not available, agree with the
customer to use one of the example configurations that are shown in
“Appendix A. Example Configurations” on page 27, then go to “Connecting
SSA Cables to the 7133 Model T40” on page 12 or to “Installing and
Connecting Advanced SSA Optical Extenders to the 7133 Model T40” on
page 14, as required by the customer.
Installing and Testing the 7133 Model T40 11