Compaq DWZZH - Manual (Page 32)

DWZZH 16–UltraSCSI Hub
Glossary–2 EK–DWZZH–UG. D01
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.