Fujitsu ScanSnap S500M Operator's Manual page 70

4. Load the document onto the scanner.
5. Press the [SCAN] button
⇒
The document is scanned in "Simplex scan" mode.
HINT
54
.
To select the "Duplex scan" mode again, go to step 2 and select "Duplex Scan
(double-sided)" instead. The selected setting is valid until you change it again.