User Manual

4.2.10. Setting of duty cycle:
When the present selection of waveform is square or ramp(including pos-square and pos-ramp), users may
press【Duty】key to display present duty cycle value, input duty cycle value with numeric keys or adjusting
knob, then the output will be square or ramp with a fixed duty cycle value. The definition of square duty cycle
is the ratio of high level time of one square to the period of this square. The usual thought of square duty
cycle is 50％, waveforms with other duty cycle are usually named pulse. The definition of ramp duty cycle is
the ratio of rising time of one ramp to the period of this ramp. The ramp duty cycle is usually named ramp
symmetry, ramps with symmetry of 0% or 100% are usually named sawtooth wave, and ramp with symmetry
of 50% is named triangle wave.
When the frequency of square is comparatively high, the setting of duty cycle is limited by the edge time, in a
relationship as below formula:
Duty cycle× Period≥2× Edge time
or
Duty cycle × Period ≤ Period－（2× Edge time）
4.3. output phase setting
Under single frequency function, press 【Menu】to light “Phase” and display output phase value, input
phase value with numeric keys or adjusting knob, there are only two values, 0°and 180°, of output phase.
When setting the phase as 0°, the phase of signal from 《OUTPUT》port and is the same with the one of
signal from《SYNC》port，while when setting the phase as 180°, the two are opposite.
4.4. Frequency sweeping
In frequency sweep, the output frequency changes from the start frequency point to the end frequency point
according to the setting sweep time. Users may sweep within the whole frequency range. During this
process, the phase of output signals is continuous. All the 16 kinds of waveform could be swept, of course it
makes no sense to sweep DC or noise. Linearity frequency sweeping is similar with ramp frequency
modulation, with the difference of, frequency sweeping does not use modulation waveform, but continuously
output a series of discrete frequency points according to certain time interval.
Press【Sweep】key and the generator enters frequency sweeping function.
4.4.1 Start and end frequency:
* Press【Menu】key and “Start” letter and then set start frequency point.
* Press【Menu】key to light “Stop” letter and then set end frequency point.
* If the end frequency value is more than the start frequency value, the sweep is positive from lower
frequency to higher frequency, increasing step by step from the start frequency to the end frequency and
then return to the start frequency.
* If end frequency value is less than the start frequency value, the sweep is opposite from higher frequency
to lower frequency, decreasing step by step from the start frequency to the end frequency and then return
to the start frequency.
4.4.2 Sweeping time:
* Press【Menu】-key and then set sweep time value.
* Sweep time means the time of sweeping from the start frequency point to the end frequency point.
* The sweep time of every frequency point is the same, so the longer the sweep time is, the more
frequency points are swept, the less the step of the frequency point is, and the finer the sweep is.
* The shorter of the sweep time is, the less frequency points are swept, the more the step of the frequency
point is, and the rougher the sweep is.
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