Screen Navigation

This chapter focuses on some very tried-and-true techniques of navigation and entry. Screens typically used in business are for transaction functions, whereas the manipulation of control actions in a process through video screens is a navigation function. The most obvious navigation tool is the keyboard. Protection for keyboards must include shielding radio frequency interferences from communication devices or electromagnetic interferences from lighting fixtures and appliances. Both can trigger “keystrokes” without an operator pushing anything. One advantage of a mouse and trackball over a touch screen is that the targets can be smaller because the selection is more precise. A touch screen is a video screen (cathode ray tube) with which the user can interact by touching icons on a screen display rather than through a keyboard or mouse. The chapter also discusses the audio access in the control room and voice commands.