You can use you mouse, trackball, touch-screen, and your keyboard to change displays, acknowledge alarms, enter data etc.
The Function Keys (F1 through F12), Ctrl, Alt, and TAB keys allow display and control actions for Field Mounted panels that have "membrane" style keypads. This also provides redundancy in the event the mouse.
Engineers can also build "pushbuttons" on Graphic Displays to call other displays and menus.