FIRST TIME USE
3-8
Modulation field
This field shows all the current modulation settings for the selected signal source: type of
modulation; modulation deviation/depth; modulation frequency; waveform type (shown
graphically); modulation ON or OFF.
The type of modulation is selected by the
[FM],
[AM]
and
[
ϕ
M]
keys. Only two of the three keys
are shown at any time. This is because the display will already be showing the parameters for the
omitted selection key.
Modulation deviation/depth is selected by the
[FM Devn], [AM Depth]
and
[
ϕ
M Devn]
keys.
Modulation frequency is selected using the
[FM Mod Freq]
,
[AM Mod Freq]
and
[
ϕ
M Mod Freq]
keys and the value is shown on the screen against
ModF:
.
The type of waveform (sine, triangle or square) is obtained from a menu after pressing the
[Select
Waveform]
key. For external modulation this key is replaced by the
[Select Coupling]
key.
Internal modulation switching is controlled by the
[FM ON/OFF], [AM ON/OFF]
and
[
ϕ
M
ON/OFF]
keys.
Error message field
Error messages are displayed here when, for example, you exceed a parameter limit. A list of error
messages is given at the end of this chapter.
Soft key fields
These fields can hold up to 12 soft key labels. Some soft keys are used to select a field for data
entry (for example,
[Carrier Freq]
), in which case the soft key label will remain highlighted after
being pressed to show that any subsequent data entry applies to that function.
Other soft keys may perform an action (for example, turning the modulation on or off), in which
case the label will flash to acknowledge the key-press.
Some soft keys cause another menu to be displayed, in which case there is no highlighting or
flashing of the label, the change of menu acknowledges the key-press.
