HP Deskjet 6540 Color Inkjet Printer - Manual (Page 155)

Note: Do not press the buttons on either side of the duplexer when installing
it in the printer. Use the buttons only when removing the duplexer from
the printer.
16.1.2 Enabling the duplexer
1. Open Chooser and select the printer.
2. Click Setup.
The Printer Setup dialog box appears.
3. Select Installed on the Duplex Unit menu, then click OK.
4. Close Chooser.
Note: After the duplexer is enabled, it is not necessary to re-enable it every time
you print.
16.1.3 Printing a booklet automatically
To print a booklet automatically, one of the following accessories must be attached
to the printer:
Automatic Two-Sided Printing Accessory
Auto Two-Sided Print Accessory with Small Paper Tray
The two-sided printing accessories only support certain paper types. For a list of
supported paper types, see the specifications for either the Automatic Two-Sided
Printing Accessory or the Auto Two-Sided Print Accessory with Small Paper Tray .
HP Deskjet 6500 series printers User's Guide
155