Compaq AA-RHGWB-TE manual Terminating the Shared Scsi Bus, DS-BA35X-DA Personality Module Switches

______________________ 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

OFF ON

1 2 3 4

SCSI Bus

Termination

Switch S4

ON

OFF

1 2 3 4 5 6 7

SCSI Bus Address

Switch S3

ZK-1411U-AI

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