Understanding Scsi; Preparing Scsi Devices For Installation; Scsi Ids - Adaptec USB2Xchange User Manual

Understanding SCSI

SCSI (pronounced "scuzzy") stands for Small Computer System
Interface. SCSI is an industry standard computer interface for
connecting SCSI devices (such as a hard disk drive, CD-ROM
drive, or scanner) to a common SCSI bus.
A SCSI bus is the path or channel that connects your computer,
USB2Xchange adapter, and one or more SCSI devices. It's not a
physical object that you can point to; instead, it's the whole
collection of SCSI cables and devices (including the USB2Xchange)
that make up the communication channel. The size of the bus
grows when more devices are added. When there is activity on the
SCSI bus, the LED on the top of your USB2Xchange flashes.
For the SCSI bus to function properly, each SCSI device must have a
unique SCSI ID and must be correctly terminated. For more
information, see the next section

Preparing SCSI Devices for Installation

When preparing to install SCSI devices, make sure to:
Check the SCSI IDs. Ensure that the USB2Xchange adapter and
I
each SCSI device you want to connect to it has a unique SCSI
ID. See the next section,
Use only high-quality SCSI cables to ensure reliable data
I
transfer. See
Terminate the ends of the SCSI bus. See
I
Bus on page 25

SCSI IDs

SCSI IDs identify each device on the SCSI bus and determine
priority when two or more devices are trying to use the SCSI bus at
the same time. The SCSI card is also identified by a SCSI ID. For the
USB2Xchange adapter, SCSI IDs are numbers between 0 and 7.
Adaptec presets the USB2Xchange to SCSI ID 7. You cannot change
this setting. SCSI ID 7 has the highest priority on the SCSI bus; the
remaining SCSI IDs descend in priority from 6 to 0.
Use SCSI ID 0 for the first SCSI hard disk drive.
(Preparing SCSI Devices for
SCSI
Using SCSI Cables on page 26
for more information.
IDs, for more information.
for more information.
Terminating the SCSI
Understanding SCSI
Installation).
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