Agilent Technologies E4400-90326 LCD display provides information on the current instrument

ESG Family Signal Generators			Exploring the User Interface
			Front Panel
21.	Display	The LCD display provides information on the current instrument
		state such as modulation status, frequency and amplitude settings,
		status indicators, and error messages. Softkey labels corresponding
		to their adjacent keys are located on the right-hand side of the
		display.
22.	Hold	Press this hardkey to deactivate the currently active function and
		blank the softkey menu. Once Hold is pressed, the front panel knob,
		the arrow keys, and the numeric keypad have no effect. To return to
		normal operation, press a function or menu hardkey.
23.	Softkeys	Press a softkey to activate the function indicated by the
		corresponding label on the display.
24.	Knob	The knob increases or decreases a numeric value. Any of the values
		that can be set through the numeric keypad or the step keys can
		also be set with the knob.
25.	Amplitude	Press this hardkey to activate the power level amplitude function so
		that you can change the amplitude of the RF output.
26.	Frequency	Press this hardkey to activate the frequency function so that you
		can change the frequency of the RF output.
27.	Save	This hardkey lets you save up to 100 different instrument states in
		a combination of 100 memory registers and 10 register sequences.
		The number of states you can save, however, is limited by the size of
		whatever else is stored in the file system.
28.	Menu Keys	These hardkeys provide access to the signal generator’s primary
		functionality. Press these keys for access to softkey menus where
		you can configure modulations, step and list sweeps, and various
		frequency and power capabilities.
29.	Incr Set	Press this hardkey to toggle between the current active function and
		the increment size for that function. With increment size selected,
		you can change the current increment value.

Quick Start Guide 2-5