Nikon 35MM Film Scanner LS-10E - Manual (Page 46)

[a]
OPEN
OFF ON
MM: imifl:
[b]
Fig. 3.8 SCSI termination network used with the
LS-10 scanner
Terminaison interne du LS-10
SCSI-AbschluB an Scanner LS-10
3-4 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
termination is placed on each end of the bus. The effects
of this termination may be subtle, but are critical.
Typically, the computer sits at one end of the SCSI bus.
Assuming this is the case, the SCSI controller in the
computer has to be terminated.
Warningl
Incorrect SCSI termination can cause unpredictable
errors.
If one other SCSI peripheral shares this SCSI bus, it
also has to be terminated. If additional SCSI devices sit
on the bus 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.
Improperly terminated SCSI peripherals can fail
immediately or may work correctly for a week before
generating their first errors.
Terminating an LS-10
The internal-mount LS-10 scanner uses a set of
termination networks as seen in Figure 3.8. The pins of
these termination networks are numbered beginning
with number one. The number one pin is indicated with
a black dot.
[a] SCSI termination off
[b] SCSI termination on
Fig. 3.9 SCSI internal flat cable
Cable en nappe SCSI interne
Internes SCSI-Flachkabel
3-5 SCSI Cables Used with Internal
Scanners
The internal SCSI cable is a 50-pin flat cable with two
identical stamped connectors on each end. One end of
this cable will connect to the SCSI controller while the
other end will connect to the connector on the rear of
the LS-10 scanner. A typical SCSI internal cable is seen
in Figure 3.9.
[c] SCSI flat cable
[d] SCSI 50-pin connectors
[e] Connector protection key
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