IBM 7133 D40, Руководство по обслуживанию

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Forced Inline mode can be set by:
v
A command from the subsystem service aids
v
A command from the command line tool
v
Jumpers on the bypass card
If Forced Inline mode is set by the jumpers, the mode cannot be changed by the
subsystem service aids or by the command line tool.
Forced Bypass Mode
When the bypass card is set for Forced Bypass mode, the disk drive modules that are
on each side of the bypass card are connected to each other. (For example, in
Figure 24 on page 43, disk drive modules 12 and 13 are connected together through
the bypass card.) Connections that have been made to the external connectors of the
bypass card have no effect. The disk drive modules that are on each side of the bypass
card remain connected to each other.
A typical use for Forced Bypass mode is to ensure that the connection between disk
drive modules that are on each side of the bypass card cannot be broken or changed
by the addition of external cables.
Forced Open Mode
When the bypass card is set for Forced Open mode, no connections through this
bypass card are active.
A typical use for Forced Open mode is to ensure that the interface is isolated.
Resetting Bypass Card Modes
If the bypass card modes have been set in such a way that the using system can no
longer get access to the 7133, you cannot use the service functions to change those
modes. You can, however, manually reset the modes to their default settings.
Attention: When you reset the modes manually, all bypass cards that are not jumpered
for Forced Inline mode are reset to Automatic mode in this 7133. Your configuration
might be seriously affected.
To reset the modes, hold all three ID push buttons (see “ID push buttons” on page 11)
pressed until the display flashes after approximately 10 seconds. All bypass cards that
are not jumpered for Forced Inline mode are reset to Automatic mode in this 7133.
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7133 Models D40 and T40 Service Guide