Dell 3115cn Color Laser Printer - Manual (Page 409)

* Only displayed when an optional 550-sheet paper feeder is installed on the multifunction printer.
Setup printing Letter Plain from Multipurpose Feeder
On the printer operator menu, press until >SETUP appears, and then press . 1.
Press until >Tray Settings appears, and then press . 2.
Press until >MPF appears, and then press . 3.
4.