HP 54750A, User Manual, Page: 55 / 478

The Instrument at a Glance
The Front Panel
Histogram, Limit T est
and Mask T est
The entire area below the timebase area is used by the Histogram, Limit T est
and Mask T est features while in their respective menus .
Softkey menu area Softkey menus are displayed in this area. The menu that is displayed
depends on which key is pressed. The HP 83480A, 54750A Quick Start
Guide contains an explanation of how the softkeys operate .
Memory bar The memory bar represents the entire waveform record. The highlighted part
of the memory bar represents the portion of the waveform record currently
on the display . When possible , the acquisition hardware is set up so all of the
waveform record is displayed on the screen. When the acquisition is stopped
and the waveform is magnied with the time base controls , the memory bar
indicates which portion of the waveform is viewed.
Entry devices
The entry devices are:
the knob
the arrow keys
the keypad
Y ou can use the entry devices to change the numeric settings of some
softkeys , such as trigger level, or to select an item from a list of choices .
When using the entry devices to scroll through a list of choices , you may
notice the background color of each item change as you scroll through the
list. Occasionally , a particular feature may not be available . In this case , the
background color of that feature will not change as you scroll through the list.
1-13