Ricoh IS450DE Operator's Manual page 21

SETTING UP THE SCANNER
*2 Terminators
Generally you need to have two terminators at each end of a SCSI chain. If you
connect this scanner at the end of a SCSI chain, you should cap the scanner's
unused SCSI port with a terminator. If the scanner is located inside of a SCSI
chain that is already terminated, you do not need to terminate the scanner's
other port.
1-7