Compaq DWZZH manual Sbb

DWZZH 16–UltraSCSI Hub

host adapter

A device that connects the host system I/O bus (for example, a PCI bus) to the storage SCSI bus. A host adapter performs the lower layers of the SCSI protocol and normally operates in the initiator role.

initiator

A SCSI device that requests another device on the bus to perform an operation. Any device on the bus can be an initiator or a target.

logical bus

A single-ended, or differential, physical bus connected to a differential, physical bus by a SCSI bus converter.

personality module

The BA356 module that interfaces the SCSI-bus to the BA356 shelf.

physical bus

Two SCSI terminators separated by cables, connectors, and/or the backplane circuitry.

SBB

StorageWorks building block. The basic building block of the StorageWorks product line. Any device conforming to shelf mechanical and electrical standards installed in either a 3½-inch or 5¼-inch carrier is considered to be an SBB, whether it is a storage device, a power supply, or other device.

SBB shelf

The common name for any StorageWorks shelf that contains only power supply and storage SBBs.

SCSI

Small Computer System Interface. This ANSI interface defines the physical and electrical parameters of a parallel I/O bus used to connect computers and devices. The StorageWorks subsystem implementation uses SCSI–2 or SCSI–3 for the transfer of data.

SCSI bus converter

Sometimes referred to as an adapter. (1) A connecting device that permits the attachment of accessories or provides the capability to mount or link units. (2) The device that connects a differential SCSI bus to a single-ended SCSI bus.

SCSI device

A host computer adapter, a peripheral controller, or an intelligent peripheral that can be attached to the SCSI bus.

SCSI device ID

The bit-significant, representation of the SCSI addressing referring to one of the signal lines numbered 0 through 15. Also referred to as target ID. For example, SCSI device ID 1 would be represented as 00001.

Glossary–2 EK–DWZZH–UG. D01