Interface Cable Specifications - Compaq SW TL881 DLT Mini-Lib/1 Reference Manual

3-24 Compaq StorageWorks TL881/TL891 Family MiniLibrary System Reference Guide

Interface Cable Specifications

The MiniLibrary is a high-performance system. To avoid degradation of
performance, use the highest-quality interface cables. The detailed
requirements for SCSI cables are set forth in ANSI X3.131-1994. All SCSI
cables used with the MiniLibrary module meet at least the following
requirements:
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Shielded or double-shielded, as required to meet EMI specifications
Impedance match with cable terminators of 132 Ω
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Characteristic impedance between 90 and 132 Ω, required
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Each end of the twisted pair ground must be connected to chassis
ground.
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The maximum cable length for a single-ended Fast SCSI bus is
9.8 ft (3 m).
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The maximum cable length for a differential Fast SCSI bus is
82 ft (25 m).
NOTE: See Appendix H, "Interconnect Characteristics for Signals," for LVD/SE, SE, and
HVD recommended minimum conductor sizes.
IMPORTANT: When calculating the overall length of the bus, be sure to include the
internal cabling of the module, as follows:
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MiniLibrary Base Module:
TL881:
DLT0 19 in (48 cm)
DLT1 27 in (69 cm)
TL891/DLT8000:
DLT0 17 in (43 cm)
DLT1 26 in (66 cm)
SCSI Jumper:
12 in (30 cm)
Robotics Control:
Wide SCSI 35 in (89 cm)