9
With the voltage-selection switch set properly, plug the female end of the
power cord into the back of the unit and plug the male end of the cord into
your AC power outlet.
3.2 Recommended Cable
Twisted-Pair Cable—
A 50-pin shielded cable and connector will provide a
connection with the greatest noise immunity and distance from your host or
peripheral to the SCSI Fiber Optic Extender. But note that this cable
connection may never exceed 6 feet (19.7 m).
Section 3.5
describes
requirements for connecting to the SCSI Bus.
Appendix B
shows the
standard SCSI connector pinning chart.
Fiberoptic Cable—
Up to 3000 feet (about 1 km) of standard, full-duplex
multimode 62.5/125 µm, 100/140 µm, or 50/125 µm fiberoptic cable.
Improper connector termination, splicing of the fiberoptic cable, or use of
other cable diameters will result in reduced link distances and increased
data error rates.
Neither of these cables are included with this unit. Call your supplier to
order them separately.
3.3 Internal/External Terminator Options
The SCSI Fiber Optic Extender features internal active SCSI bus
termination to improve the cable-matching characteristics between multiple
SCSI devices. Since some applications require external terminators, you
may remove these internal terminators for added application flexibility.
To remove the internal terminators, remove the four screws on the bottom
of the unit (see
Figure 3-2
) and gently unplug terminators RN1, RN2, and
RN3 from their positions on the printed circuit board (PCB)
(see
Figure 3-3
).
Normally, terminators should be installed on opposite ends of the SCSI bus.
Note that data errors may result if more than two sets of terminators are
installed on any SCSI bus.
3.4 Internal Terminator Power and Fuse
The SCSI Fiber Optic Extender contains a replaceable internal fuse to
provide power for an external terminator. This fuse supplies 1 amp at
5 volts to the TERMPWR signal. The fuse is installed in the socket labeled
F2 on the PCB (see
Figure 3-3
). The Extender contains internal protection
and will not be affected if other SCSI devices provide terminator power.
CHAPTER 3: Installation
