Ricoh D129 Service Manual page 819

ADF Org Feeds
8221
These SPs count the number of pages fed through the ADF for front and
back side scanning.
001 Front
002 Back

When 1 sheet is fed for duplex scanning the Front count is 1 and the Back count is 1.

If a jam occurs during the job, recovery processing is not counted to avoid double counting.
Also, the pages are not counted if the jam occurs before the first sheet is output.
SM Appendix
Number of front sides fed for scanning:
With an ADF that can scan both sides simultaneously, the Front
side count is the same as the number of pages fed for either
simplex or duplex scanning.
With an ADF that cannot scan both sides simultaneously, the
Front side count is the same as the number of pages fed for
duplex front side scanning. (The front side is determined by which
side the user loads face up.)
Number of rear sides fed for scanning:
With an ADF that can scan both sides simultaneously, the Back
count is the same as the number of pages fed for duplex
scanning.
With an ADF that cannot scan both sides simultaneously, the
Back count is the same as the number of pages fed for duplex
rear-side scanning.
3-215
[0 to 9999999 / 0 / 1]
System SP Tables-8
D129/D130