Advantech PCA-6181, Руководство пользователя, Страница: 92 / 126

7 8 PCA-6181 User’s Manual
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If you are booting your computer from a SCSI hards disk drive
connected to the SCSI bus, the Boot SCSI ID setting in the
SCSI Select utility must correspond to the SCSI ID of the deveice
from which you are booting. By default, the Boot SCSI ID is set to 0.
We recommend that you do not change this setting.
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In Windows
©
95/98, you can use the Device Manager to determine
which SCSI ID is assigned to each installed SCSI device.
6.4 Terminating the SCSI Bus
To ensure reliable communication on the SCSI bus, the ends of the
SCSI bus must be properly terminated. This is accomplished when the
device at the end of the each cable, or the end of the cable itself, has a
terminator installed (or enabled). Terminators must be removed, or
termination must be disabled, on devices between the ends of each
cable.
Since the method for terminating a SCSI device can vary widely, refer
to the device’s documentation for instructions on how to enable or
disable termination. Here are some general guidelines for termination:
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Internal Ultra 160 and Ultra 2 SCSI devices come from the factory
with termination disabled and cannot be changed. Proper termination
for internal Ultra 160 and Ultra2 SCSI devices is provided by a 68-pin
Internal LVD (low voltage differential) SCSI cable, which has a built-
in terminator at its end.
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Termination on non-Ultra 160 and Ultra2 internal SCSI devices
usually is controlled by manually setting a jumper or a switch on the
device, or by physically removing or installing one or more resistor
modules on the device.
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Termination on most external SCSI devices is controlled by installing
or removing a SCSI terminator. However, termination on some
external SCSI devices is enable or disabled by setting a swetich on
the back of the SCSI device.
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The last external Ultra160 or Ultra2 SCSI device must be terminated
with an LVD/SE (low voltage differential/single ended) terminator