11
Display Contrast
All parameter settings are displayed on the 20 character x 4 row backlit liquid crystal display
(LCD). The contrast may vary a little with changes of ambient temperature or viewing angle but
can be optimised for a particular environment by using the front panel contrast control. Insert a
small screwdriver or trimmer tool through the adjustment aperture marked LCD and rotate the
control for optimum contrast.
Keyboard
Pressing the MENU key calls the top-level menu from which all functions can be accessed.
Selections are made from this menu using the display soft-keys and numeric values are then
changed using the numeric keys or rotary control, see the Principles of Editing section.
The keys are as follows:
•
MENU calls the top-level menu screen from which the main functions can be directly
selected. These are WAVEFORM, FREQUENCY, AMPLITUDE, DC OFFSET, SYMMETRY,
MODE, UTILITY and AUX OUT. Pressing the associated soft-key of any of these functions
calls a further screen which permits the parameters of that function to be edited either from
the numeric keypad or by using the rotary control/cursor keys.
•
Numeric/Unit keys permit direct entry of a value for the parameter currently selected. Thus,
having selected the FREQUENCY screen (by pressing the FREQUENCY soft-key on the
MENU screen), a new frequency of 100kHz, for example, is set by pressing 1, 0, 0, kHz.
CE (Clear Entry) undoes a numeric entry digit by digit. ESCAPE returns a setting being
edited to its last value.
•
Eight soft-keys around the display are used to directly set or select parameters from the
currently displayed menu; their operation is described in more detail in the next section.
•
The STATUS key always returns the display to the default start-up screen which gives an
overview of the generator’s status. Pressing STATUS again returns the display to the
previous screen.
Further explanations will be found in the detailed descriptions of the generator’s operation in the
sections that follow.
Status Display
After the messages at switch-on, or at any time the STATUS key is pressed, the Status display is
shown. With the generator set to the factory defaults (Appendix 2), the display will be:
WAVE:sine
FREQ:10·0000kHz CONT
AMPL:+4·00Vpp
DC:+0·00Vdc
(+0·00V)
This display gives an overview of the status of the main generator parameters. If a waveform is
selected for which symmetry can be set (see Specification) the additional field of
SYM
metry is
shown to the right of the waveform type, see example below:
WAVE:square SYM:35%
FREQ:10·0000kHz CONT
AMPL:+4·00V
DC:+0·00Vdc (+0·00V)
For convenience, the WAVEFORM, FREQUENCY, AMPLITUDE, DC OFFSET, SYMMETRY and
MODE screens can be directly selected from the Status display, (i.e. without having to first return
to the main MENU) by pressing the appropriate soft-key beside WAVE, FREQ, AMPL, etc.
