The PC_OCD_DUPLEX_VERT box contains the command or commands which the Universal Printer Driver issues to enable vertical-duplex printing. (When pages are printed in vertical-duplex mode, they are printed in such a way that the top and bottom edges of consecutive pages may be bound; when pages are printed in horizontal-duplex mode, they are printed in such a way that the left and right edges of consecutive pages may be bound.)
The Diconix 150 Plus printer does not support a command which enables duplex printing in either the vertical or horizontal directions; therefore, the PC_OCD_DUPLEX_VERT box is empty.
For the HP LaserJet IIP, the Vertical Duplex command (ESC&l1S) is required to enable vertical duplex printing.
To specify the Vertical Duplex command, type the following in the PC_OCD_DUPLEX_VERT box:
\x1B&l1S