Compaq TruCluster Server AA-RHGWB-TE, Manual

Page: 255 / 320

______________________ Notes ______________________
S4-3 and S4-4 have no function on the DS-BA35X-DA personality
module.
See Section 9.3.2.2 for information on how to select the device
SCSI IDs in an UltraSCSI BA356.
Figure 9–3 shows the relative positions of the two DS-BA35X-DA switch
packs.
Figure 9–3: DS-BA35X-DA Personality Module Switches
1
OFF
2
ON
3
SCSI Bus
Termination
Switch S4
4
ZK-1411U-AI
OFF
SCSI Bus Address
Switch S3
ON
1 2 3 4 5 6 7
9.2 Terminating the Shared SCSI Bus
You must properly connect devices to a shared SCSI bus. In addition, you
can terminate only the beginning and end of each SCSI bus segment (either
single-ended or differential).
There are two rules for SCSI bus termination:
• There are only two terminators for each SCSI bus segment.
• If you do not use an UltraSCSI hub, bus termination must be external.
Note that you may use external termination with an UltraSCSI hub,
but is is not the recommended way.
Configurations Using External Termination or Radial Connections to
Non-UltraSCSI Devices 9–5