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To set carrier frequency, please use the multi-functional control and direction keys or press soft key Freq, input the
required value and select the unit.
Select modulation source
The function/arbitrary waveform generator can select internal or external modulation source. After you use PSK function,
the modulation source is internal by default. You can change it with the multi-functional control on the the interface for
using PSK function or by pressing soft function key Source.
Figure 4- 84 Select modulation source
1)
Internal source
When using an internal modulation source, internal modulation wave is sine wave. The phase relation between oscillation
starting and stop can be designated by setting OSK rate.
2)
External source
When using an external modulation source, rate will not show in the parameter list, when an external waveform will be
used to modulate carrier waveform. OSK output phase is determined by logic level on external digital modulation interface
(FSK Trig connector). For example, when external input logic is low, carrier phase is output; when external input logic is
high, modulation phase is output.
Set OSK rate
The frequency between carrier phase and modulation phase can be set when using an internal modulation source. After
you use OSK function, you can set QPSK rate, which is in the range of 2mHz~1MHz and 500Hz by default. You can
change it with the multi-functional control and direction keys on the interface for using PSK function or by pressing Rate.
Set oscillation period
Oscillation period is oscillation period of internal crystal oscillator. Press soft function key OcsTime to highlight it, and input
the required value through the numeric keyboard or direction keys and control, which is in the range of 8ns -
1ms and 50μs
by default.
Comprehensive example
First set the instrument run in OSK mode, and then set an internal sine wave of 2kHz and 2Vpp as carrier signal. Set rate
to be 100Hz and oscillation period to be 1μs.
The specific steps are as follows:
