Nikon 35MM Film Scanner LS-10E - Manual (Page 20)

Fig. 2.4 SCSI termination on the rear of the LS-10E
scanner
Terminaison SCSI à l’arrière du scanner
LS-10E
SCSI-AbschluB an der Riickseite des
Scanners LS-10E
2-3 Terminating the SCSi Chain
The SCSI chain is an electrical bus connecting two or
more devices. It is critical that this bus be correctly
terminated for the SCSI peripherals to work properly.
Termination is an electronics term that applies to the
impedance found at both ends of the bus. The electrical
signals on the SCSI bus are changing rapidly between
their digital “on” and “off” states. To minimize noise, a
terminator is placed at each end of the bus. The effects
of this termination may be subtle, but are critical.
"Warning! ’ j "
Incorrect SCSI termination can cause unpredictable
Typically, the computer sits as one end of the SCSI bus.
Assuming this is the case, the SCSI controller in the
computer has to be terminated.
If another SCSI peripheral shares this SCSI bus, it also
has to be terminated. If additional SCSI devices sit on
the bus in between the two end SCSI devices, these
devices can NOT be terminated. Only two terminated
devices can reside on the SCSI bus, one at each end.
Terminating an LS-10E
The LS-10E scanner box is configured with two 50-pin
SCSI connectors on the rear of the LS-10E unit as shown
in Figure 2.4. Install the standard 50-pin SCSI terminator
onto the bottom connector if termination is desired. If
the LS-10E sits in the center of a SCSI chain, then by
necessity, the bottom connector will be used for a SCSI
terminator.
[a] SCSI connectors
[b] TERM. PWR. switch
[c] SCSI terminator
Term. Power Switch
If the terminator-power is supplied by the other
connected peripherals, always turn off the “TERM.
PWR” switch on the rear panel.
If it is not so supplied, always turn on the switch.
ON: Supplies SCSI terminator-power
OFF: Stops supplying SCSI terminator-power
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