Ricoh IS450S Service Manual page 27

22 December 1998 SCANNER MECHANISMS
Read Size Command
If selected, this is done after document table lift/paper feed.
If the scanner receives a Read Size command in ADF mode, it detects the
document size in the main scan direction as described on the previous page.
The scanner sends the width data to the host computer.
Abort and Unload Commands
These can occur at any time during the basic scanning procedure.
When the CPU receives the Abort or the Unload command during paper transport,
the scanner feeds out any original that is in the ADF.
2-13