HP Visualize J5000 Owner's Manual page 127

Narrow Single-Ended or the Ultra2 Wide Low-Voltage Differential SCSI
bus on this system, they must adhere to cabling, termination and bus
length restrictions discussed in this chapter to assure functionality of the
SCSI busses.
Because Ultra2 Wide Low-Voltage Differential SCSI is a relatively new
technology, there can be products which are advertised as LVD
compliant, but may not meet LVD specifications. Therefore, additional
caution must be exercised when choosing Ultra2 Wide Low-Voltage
Differential SCSI
Hewlett-Packard Company to connect to the Ultra2 Wide Low-Voltage
Differential SCSI bus on this system. For example, the cabling inside one
of these devices in question may not have a differential impedance
between 110 and 135 ohms and it may be constructed in a way such that
the device has considerable crosstalk on critical signals, such as Reset,
Select and Busy. Failure to strictly adhere to the Ultra2 Wide
Low-Voltage Differential SCSI bus specifications will impact the
performance of the LVD bus. The Ultra2 Wide Low-Voltage Differential
interface is a much higher performance SCSI bus than previous SCSI
buses and is more sensitive to adherence to the electrical specifications.
Low-voltage differential signaling specifications are described in the
SCSI Parallel Interface-2 (SPI-2) document and in the Electrical
Characteristics of Low Voltage Differential Signaling (LVDS) Interface
Circuits TIA/EIA-644 document. Both of these documents can be
obtained from:
Global Engineering Documents
15 Inverness Way East
Englewood, CO 80112-5704
800-854-7179 or 303-397-7956
Chapter 7
devices other than
SCSI Connections
SCSI Restrictions
those supported by
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