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5. Interfacing Requirements
5.1 SCSI Cable Interface Requirements
The SCSI Fiber Optic Extender can be installed at any point on the SCSI bus. The
Extender provides an optically isolated SCSI bus over extended distances.
Terminators must be installed on both the local and extended bus. Make sure that
a maximum of two terminators are installed on each bus.
The desktop SCSI Fiber Optic Extender contains a 68-pin SCSI connector.
The SCSI Fiber Optic Extender supports a maximum cable length of 25 meters
(82 feet) at Ultra2 SCSI data rates (80 MBps).
NOTE
Peripherals operating at Ultra SCSI data rates require shorter cable
lengths for proper operation. The total cable length for a single-ended
Ultra SCSI bus should be no longer than 1 meter (3.3 ft.) and differential
cables 12 meters (39.4 ft.).
NOTE
Do not intermix single-ended and differential devices on any one side of
the SCSI chain unless a SCSI differential converter is used to convert
from one bus type to the other.
5.2 Internal/External Terminator Options
The SCSI Fiber Optic Extender contains an internal SCSI bus termination. The
internal terminator can be disabled by the user for added flexibility. Data errors
may result if more than two sets of terminators are installed on any SCSI bus.
Terminators should normally be installed on opposite ends of the SCSI bus. To
disable or enable the internal terminators, remove the four screws on the bottom
of the unit and configure as shown in
Figure 5-1
.
NOTE
The default setting is “INSTALLED” (internal termination enabled).
Figure 5-1. External terminator enable.
CHAPTER 5: Interfacing Requirements
Jumper E5
