Compaq DWZZH manual Indicators, Determining the Configuration, Selecting the Scsi Cables

Chapter 2. Using the DWZZH UltraSCSI Hub

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.

2.5Determining 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.

2.6Selecting 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.

2.7Placement 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.

EK–DWZZH–UG. D01 2–7