The PC_OCD_DUPLEX_HORZ box contains the command or commands which the Universal Printer Driver issues to enable horizontal-duplex printing.
The Diconix 150 Plus printer does not support duplex binding; therefore the PC_OCD_DUPLEX_HORZ box is empty.
For the HP LaserJet IIP, the Horizontal Duplex command (ESC&l2S) is required to enable horizontal duplex printing.
To specify the Horizontal Duplex command, type the following in the PC_OCD_DUPLEX_HORZ box:
\x1B&l2S