Terminating The Scsi Bus - Adaptec AVA-2906 User Reference Manual

Terminating the SCSI Bus

To ensure reliable communication on the SCSI bus, you must termi-
nate both ends of the SCSI bus. If the SCSI Card 2906 is connected at
one end of the SCSI bus, you must still terminate the device at the
other end. Termination prevents the signal from bouncing off the
end of the cable and interfering with the original signal.
If the SCSI Card 2906 is connected in the middle of the SCSI bus, it
will not terminate itself and you must terminate the SCSI devices
connected at both ends of the SCSI bus.
The method for terminating a SCSI device varies widely. Refer to the
SCSI device's documentation for instructions on how to enable or
disable termination. Here are some general guidelines for
termination.
Termination on internal SCSI devices usually is controlled by
manually setting a jumper or a switch on the device, or by
physically removing or installing a terminator module on the
device. The internal SCSI device at the end of the cable must be
terminated.
Termination on external SCSI devices usually is controlled by
installing or removing a SCSI terminator. On some external
devices, termination is controlled by setting a switch on the
back of the device. The external SCSI device at the end of the
cable must be terminated.
By default, termination on the SCSI Card 2906 is set to
Automatic (the preferred method). To manually set termination
on the SCSI Card 2906, see Configuring the SCSI Card 2906 with
SCSISelect on page 15.
Most SCSI devices come from the factory with termination
enabled. Some SCSI devices include a terminator block or
pass-through terminator. See your SCSI device documentation
for information on enabling and disabling termination.
SCSI Card 2906 User's Reference
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