Canon imageRUNNER ADVANCE DX C7780i User's Manual (Notification Of New And Enhanced Functions page 32

<Use Optional Output Tray>
(Settings/Registration)
Specify whether to use the tray of the optional equipment as the output tray.
● The output trays that can be used vary depending on the optional equipment attached, such as the
finisher. For more information, see Optional Equipment.
Other Changes to the User's Guide
<Function Settings> <Common>
30
<Paper Output Settings>