1.3 SCSI Concepts
Before configuring the subsystem, you must first understand some basic SCSI concepts so that the subsystem and SCSI devices will function properly.
1.3.1 Multiple SCSI Format Support
The subsystem support the SCSI interface standards listed below. Note that the data bit and cable length restrictions must be followed.
SCSI Type | Data Bit | Data Rate | Cable Length | |
8 Bits | 5 MB/Sec | 6 | m | |
Fast SCSI | 8 Bits | 10 MB/Sec | 3 | m |
Fast Wide SCSI | 16 Bits | 20 MB/Sec | 3 | m |
Ultra SCSI | 8 Bits | 20 MB/Sec | 1.5 m | |
Ultra Wide SCSI | 16 Bits | 40 MB/Sec | 1.5 m | |
Ultra 2 SCSI | 8 Bits | 40 MB/Sec | 12 m | |
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Ultra 2 Wide SCSI | 16 Bits | 80 MB/Sec | 12 m | |
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Ultra 160 Wide LVD | 16 Bits | 160MB/Sec | 12 m | |
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Ultra 320 LVD | 16 Bits | 320MB/Sec | 12 m | |
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1.3.2 Host SCSI ID Selection
A SCSI ID is an identifier assigned to SCSI devices which enables them to communicate with a computer when they are attached to a host adapter via the SCSI bus. Each SCSI device, and the host adapter itself, must have a SCSI ID number (Ultra 320 Wide SCSI = 0 to 15). The ID defines each SCSI device on the SCSI bus. If there are more than one SCSI adapter in the Host subsystem, each adapter forms a separate SCSI bus. SCSI IDs can be reused as long as the ID is assigned to a device on a separate SCSI bus. Refer to the documentation that came with your peripheral device to determine the ID and how to change it. The subsystem must be assigned a unique SCSI ID ranging from 0 to 15 for the Ultra 320 LVD SCSI host system. The default value is ID 0.
Introduction |