Microtek ScanMaker IIG User Manual page 245

Using terminators
When using an ASPI card, you almost always need to use a termina-
tor on the last device of your SCSI chain.
Terminators are little devices that sit between a SCSI device and the
cable connecting to it, or they might be on the second port of the
SCSI device at the end of a SCSI chain. Terminators can be pur-
chased from almost any computer store. When purchasing one, be
sure you get good-quality terminators, as you may experience
problems with some of the more inexpensive models. Belkin
Components is one cable manufacturer that makes reliable termina-
tors (as well as SCSI cables).
SCSI conflicts
Conflicts between your scanner and other SCSI hardware devices in
your system can happen, owing to the varying SCSI standards that
are used for SCSI peripherals today.
If you are having SCSI conflicts:
• Change the order of your SCSI devices in the daisy chain.
Because of the varying SCSI standards in use for SCSI peripher-
als, some SCSI conflicts may be resolved by moving the
scanner and other SCSI peripherals to different positions in the
chain.
• Check the SCSI ID number of your SCSI devices. Make sure
that no two devices have the same ID. The SCSI check feature
in ScanWizard for Windows can tell you what the IDs are of the
devices in your SCSI chain.
• Use a shorter cable (4 feet or shorter) for each segment of the
chain. The use of longer-than-authorized cables accounts for
more than 50% of SCSI-related problems.
• Make sure that none of the middle SCSI devices are terminated,
and make sure that only the last SCSI device is terminated.
• Always terminate the last device in your SCSI chain with an
external terminator and not an internal terminator.
• If you have a SCSI card that allows for synchronous communi-
cation, disable it. You can normally do this by boosting your
computer and pressing a special key sequence to get to the setup
menu for your SCSI card. For more information, refer to your
SCSI card hardware manual or call your card manufacturer.
Appendix G: If you have an ASPI card G-3