Exabyte EXB-8205 - Manual (Page 36)

Appendix A Installation Requirements
This appendix lists the requirements for the following items:
SCSI cable
■ SCSI connector
■ Power cable
■ Power connector
It also provides guidelines for attaching the tape drive to a
frame and adding optional chassis grounding.
SCSI Cable
The SCSI cable for connecting the tape drive to the host is
not provided with the tape drive. You must provide a cable
that complies with the appropriate safety and regulatory
agency requirements. To comply with FCC, Canadian DOC,
and VDE limits, the tape drive requires shielded cables when
the cables are external to the mounting enclosure.
General Requirements
Use a 50-conductor flat cable or 25-signal twisted pair cable.
A minimum conductor size of 28 AWG is recommended to
minimize noise effects and ensure proper distribution of
terminator power.
Ideally, to match the cable terminators, the cable should
have a characteristic impedance of 122 ohms (differential) or
132 ohms (single-ended). However, since cables with this
high of a characteristic impedance are not generally
available, somewhat lower impedances are acceptable. A
characteristic impedance of 100 ohms
± 10% is
recommended for unshielded flat or twisted-pair ribbon
cable. A characteristic impedance greater than 90 ohms is
recommended for shielded cables.
Note: To minimize discontinuities and signal
reflections, ensure that cables used on the same
bus have the same impedances.
36 EXB-8205 and EXB-8505 (Standard and XL) 302967