Check The Scsi Ids; Terminate The Ends - Adaptec 29160 Installation Manual

Below are some guidelines for setting SCSI IDs and termination
on your devices. Refer to the Adaptec SCSI Card 39160 User's Ref-
erence for more information on these topics.

Check the SCSI IDs

The Adaptec SCSI Card 39160 and each device you connect to it
must have a unique SCSI ID number ranging from 0 to 15 on
each channel. No two devices on the same SCSI channel can have
the same SCSI ID.
The Adaptec SCSI Card 39160 is preset to ID 7 for each channel
and should not be changed. If you boot from a SCSI hard disk,
make sure the hard disk SCSI ID is set to 0. (Most SCSI hard disks
are preset to SCSI ID 0 at the factory.) The SCSI IDs for internal
devices are usually set with jumpers; SCSI IDs for external
devices are usually set with a switch on the back of the device.

Terminate the Ends

To ensure reliable communication on the SCSI bus, the device at
the end of each cable, or the end of the cable itself, must have a
terminator installed (or enabled). Terminators must be removed,
or termination must be disabled, on devices between the ends of
each cable.
N
OTE
When connecting Ultra160 or Ultra2 SCSI devices, the
SCSI bus must be terminated either on the end of the cable
(with a permanent terminator) or with a separate terminating
connector. Ultra SCSI and earlier single-ended devices can
terminate the bus directly from the device. If you use an Ultra
SCSI terminator on an LVD Ultra160 and Ultra2 SCSI bus
you will force the bus to Single-ended mode, limiting the
speed and cable distance. For this reason be sure that you
have the necessary Ultra160 or Ultra2 cable or terminator
before installing the Ultra160 SCSI devices.
Adaptec SCSI Card 39160
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