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Introduction
The HSD05 array controller is the entry-level product of the StorageWorks HSD
family of bus controllers. Installed in a 3½-inch StorageWorks building block
(SBB), the HSD05 array controller is used to connect a Digital host DIGITAL
storage subsystem interconnect (DSSI) bus to up to seven Small Computer
System Interconnect (SCSI) drives.
This chapter presents a basic description of the HSD05 array controller’s
features, performance, and operating environment. The HSD05 array controller
is shown in Figure 1–1; Figure 1–2 presents a typical HSD05 installation,
showing the relationship among basic system components.
1.1 HSD05 Array Controller Description
Connecting to a single port on a host DSSI bus, the HSD05 array controller
provides connectivity for up to seven SCSI or SCSI–2 disk, tape, and solid-state
disk devices. Enclosed in a 3½-inch SBB, it is mounted in a BA350-type shelf
containing up to six drives. Two shelves may be connected together to support
the maximum seven SCSI devices.
A DSSI bus connects to the HSD05 through a connector on the front panel; SCSI
bus connection is made through the shelf backplane connector. The HSD05 is a
TMSCP™/MSCP™-compliant device that performs the translations required to
support devices conforming to SCSI or SCSI–2 protocols.
The HSD05 array controller is shipped with a DSSI trilink connector and a
DSSI terminator that fits on the trilink connector. The trilink connector allows
the HSD05 array controller to be connected as either an endpoint or a middle
(daisy-chain) node on the DSSI bus. Configured as a bus endpoint, the DSSI
terminator is used to properly terminate bus signals.
One or more HSD05 array controllers may be connected on the DSSI bus
containing RF™xx/TF™xx drives, host nodes, or other DSSI-compliant nodes (up
to eight nodes maximum).
1.1.1 HSD05 Array Controller Features and Capabilities
The HSD05 array controller provides the following features:
• Warm-swapping of attached drives (with a quiesced SCSI bus)
• Support for both OpenVMS VAX and OpenVMS AXP™ systems
• Multihost support for up to three host DSSI nodes in a cluster environment
• User-selectable SCSI and DSSI node IDs
Introduction 1–1
