Step 6: Terminating The Scsi Chain - IBM OPTIONS SCSI Manual Del Usuario

Step 6: Terminating the SCSI chain

Note: Do not confuse termination power with device termination. The SCSI
adapter normally supplies termination power, and the SCSI device
terminates the chain. For more information about termination power, see
the documentation that comes with your SCSI adapter.
A SCSI device chain is made up of one or more SCSI devices connected by a
SCSI cable to a SCSI adapter. To prevent signal reflections on the SCSI cable,
the SCSI device chain must be terminated with active terminators at both ends;
there are no exceptions.
Termination is also subject to the following guidelines:
v Ultra2 and Ultra 160 drives do not provide termination.
v Be sure to terminate only the ends of the SCSI chain. For example, the last
device and the SCSI adapter 1 shown in the following illustration must be
terminated.
v Remove any terminators or terminating jumpers on devices in the middle of
the chain.
In the following illustration, the SCSI adapter 1 is in the middle of the
chain and is not terminated.
1-8
SCSI Hard Disk Drives for IBM PCs: User's Guide