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Installation Instructions: SCSI Disk Drives
7.0TERMINATOR POWER
In order to properly terminate the SCSI bus, one of the SCSI peripherals must be
configured to supply termination power to the SCSI bus.
Use the following guidelines to determine which peripheral will be used to supply
termination power for the SCSI bus:
1.Whenever possible, only one SCSI peripheral will be configured to supply
termination power to the SCSI bus.
2.If a computer has more than one SCSI peripheral and at least one of those
peripherals is a disk drive, one disk drive will be configured to supply
termination power to the bus. The other disk or tape SCSI devices will be
configured so they do not supply termination power.
3.If a computer does not have a SCSI disk drive, but does have one or more
SCSI magnetic tape or CD-ROM drives, then one of these devices will be
configured to supply termination power.
4.If a computer with one or more SCSI peripherals is cabled to a subsystem
with additional SCSI devices, one SCSI device in the host computer would
normally be configured to supply termination power for the bus.
You should avoid having a SCSI device in both the host computer and the
subsystem configured to supply termination power. Ideally, you want the
source of the termination power for the bus to be supplied by one power
source.
For information on how to configure terminator power, see the following documents:
SCSI Disk Drives Installation Instructions, PDI-00436-20, revision A12 or
later.
AM-625/626/627 SCSI 1/4" Streaming Tape Drive Installation Instructions,
PDI-00625-00, revision A05 or later.
AM-647 DAT Tape Drive Installation Instructions, PDI-00647-00, revision
A02 or later.
PDI-00436-20, Rev. A15