Compaq DWZZH - Manual (Page 25)

Chapter 2. Using the DWZZH UltraSCSI Hub
EK–DWZZH–UG. D01 2–7
2.4.2 Indicators
The large Hub has two indicators on the front panel. The green LED indicates
that POWER is applied to the Hub, while the yellow LED indicates that the SCSI
bus is BUSY.
2.5 Determining the Configuration
The UltraSCSI Hub is used in end–bus SCSI bus configurations only. The SCSI
bus segments require TERMPOWER supplied from the remote connection to
enable the UltraSCSI Hub port for that segment. Each port on the UltraSCSI Hub
has its own terminators.
All SCSI buses are terminated at the physical ends of the bus. This is true even
when using a DWZZH UltraSCSI Hub. DWZZH UltraSCSI Hubs are factory set
to terminate the SCSI bus. No user configuration of the SCSI terminators is
required.
2.6 Selecting the SCSI Cables
The StorageWorks UltraSCSI Configuration Guidelines, EK–ULTRA–CG,
describes SCSI cables in detail. When selecting a cable you must consider the
cable connector clearance. Be sure to determine the type connector compatible
with the controller connector. In some cases you must use a right–angle
connector because there is not enough clearance to use a straight connector.
Cables connected to the DWZZH UltraSCSI Hubs are BN37A and BN38C series.
2.7 Placement of UltraSCSI Hubs
UltraSCSI Hubs are available only in SBBs and may be used only within a
BA356 StorageWorks shelf or a BA370 StorageWorks shelf. The StorageWorks
shelves are only used to provide power and cooling for UltraSCSI Hubs. An
UltraSCSI Hub and I/O devices may share the same storage shelf.
Maximum combinations of UltraSCSI Hubs and disk drives within a single shelf
and with dual power supplies are listed in Table 2-1.