F1: opens the system information window, F2: n/a, Menu: opens the system menu – Digimerge DHU104 User Manual

Page 12: Dvr setup: displays the dvr setup menu, Rec start: begin recording, F3: n/a, Return: exits from a system menu, Ptz: switches to ptz mode, Keylock: locks all keys (except the mode button), Zoom: displays one channel with digital zoom