i-Stor iS16U3, User Manual

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SATA II RAID Subsystem
User Manual 27
3.4 SCSI Termination
Two 68-pin wide SCSI connectors are provided on the back of the enclosure for
connecting the array to the system. These connectors are used in one of two ways:
ƒ
If the disk array is the only external SCSI device, or is the last external
device in a daisy-chained configuration, connect the incoming cable (the one
which is attached to the SCSI adapter) to the Host A & B in connector and
install the external SCSI Terminator on the Host A & B out connector.
ƒ
If the array is to be placed in the middle of a daisy-chained configuration,
connect the incoming cable (the one which is attached to the SCSI
adapter) to the Host A & B in connector and connect the outgoing cable (the
one which continues on to other devices) to the Host A & B out connector.
In this case, no terminator is required at the disk array but the last device in
the daisy chain must have a terminator.
Correct SCSI termination procedures require that the last devices on the SCSI
bus be terminated. If the last device is not terminated or if devices other than
the last are terminated, erratic SCSI bus performance may occur. Typically, the
system or host adapter (SCSI card inside the PC) is the first device and is
already terminated. When installing the disk array on a SCSI bus with other
devices, be sure to observe the above rules with all devices on the SCSI bus.
Consult your system and/or host adapter manual for additional information on
correct termination procedure.
Note: If you are connecting another external device after the
subsystem, make sure to disable the terminator at the
subsystem’s host channel A & B out connector. The default host
channel’s terminator is disabled.
SCSI Terminator
Host B out
Host A out