Ultrascsi Buses - Compaq StorageWorks TM RAID Array 3000 Pedestal Storage Subsystem Hardware User's Manual

1-10 RAID Array 3000 Pedestal Storage Subsystem Hardware User's Guide

UltraSCSI Buses

The pedestal contains two, 16-bit, single-ended, wide UltraSCSI buses
(factory-configured as a split bus) that connects the controllers to the disk
drives.
The split-bus arrangement is divided into two-bus paths designated device port
0 and device port 1 as shown in Figure 1–6. Port 0 connects the controller to
the upper four devices in the pedestal (IDs 8 through 11) and port 1 connects
the controller to lower three devices (IDs 8 through 10). The device addresses
on the bus are set at the factory by an internal configuration switch
(Figure 1–7).
Device
Port 0
Top Controller
ID=7
Bottom Controller (Optional)
ID=6
Figure 1-6. UltraSCSI bus port and default SCSI ID assignments
When set to a specific position, the switch controls the addresses of each SBB
slot. Figure 1–8 identifies the pedestal slot locations and their corresponding
SCSI ID addresses for each device port.
ID8
ID9
ID10
ID11
ID8
ID9
Device
Port 1
ID10
ID=7
ID=6
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