Adaptec AVA-1505A, User Reference Manual

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3
Understanding SCSI
Terminating the SCSI Bus
To ensure reliable communication on the SCSI bus, terminators must
be installed (or enabled) on the devices at the extreme physical ends
of the SCSI bus. The terminators on all devices between the physical
ends must be removed (or disabled).
Since the method for terminating a SCSI device can vary widely,
refer to the peripheral’s documentation for instructions on how to
enable or disable termination. Here are some general guidelines for
termination:
■
Termination on internal SCSI peripherals is usually controlled
by manually setting a jumper or a switch on the peripheral, or
by physically removing or installing one or more resistor
modules on the peripheral.
■
Termination on external SCSI peripherals is usually controlled
by installing or removing a SCSI terminator.
On some external peripherals, termination is controlled by set-
ting a switch on the back of the drive.
■
Termination on the SCSI Card 1505 itself is controlled manu-
ally by removing or inserting termination resistors.
■
Most SCSI peripherals come from the factory with termination
enabled.