User Manual

4.5.2. Burst count:
Press【Menu】key to light “Ncyc” indicator, and then set the burst count. Burst count represents the number
of cycles of pulse string in a repeated period, which must be small enough to be contained in one repeated
period, as following formula shows:
Pulse count＜(repeated period × pulse frequency)
If the pulse count setting is too big, the instrument will modify it to the allowable maximum value.
4.5.3. Start phase:
Press【Menu】key to light “Phase” character, and then set start and end phase value. The start and end of
the pulse string are always on the same phase of the waveform, this phase is named as the start phase. The
start phase setting range is 0° to 360°, it is not available to square wave.
4.5.4. Trigger burst:
In continuous burst mode, the generator uses internal continuous trigger source to output continuous burst
based on the repeated period and burst count set in advance. Press【trig】key to light “trig” keyboard
indicator, the burst output stop, and the generator outputs a burst each time pressing【trig】key, then keep
on the start phase point and wait for the next trigger. You can also use external trigger source, input TTL
trigger signal from the instrument rear panel “Trig In” connector. The generator outputs a burst at each rising
edge of the trigger signal, then keeps on the start phase point and waits for the next trigger. Of course, the
trigger signal cycle should conform to the restricted conditions of burst period. When trigger burst, the setting
of period is ignored. When trigger burst, press【Burst】key, the “trig” keyboard light will be off and the
generator will resume to continuous burst mode.
4.5.5. Sync output:
Regardless of in the continuous burst, single burst mode or gated output mode, a sync signal can be
outputted from the front panel “Sync” connector. It is a TTL level’s pulse wave, its rising edge is
corresponding to the burst starting point, while the falling edge is corresponding to the end of the burst. That
is to say, during the continuation of burst, sync output keeps high level; during the stop period of burst, sync
output keeps at low level.
In continuous burst, press 【Burst】key again, the keyboard indicator will be off, the generator exit burst
function and return back to continuity function.
4.6. Frequency modulation（FM）
In Frequency modulation, the frequency of the carrier is varied by the instantaneous voltage of modulating
waveform, all 16 waveforms could be used as carrier waveform, Of course, using DC or noise as carrier
wave is invalid. Before entering into frequency modulation, users should firstly set the waveform, frequency
and amplitude of carrier wave under continuity function.
Press【FM】key, the keyboard indicator of “FM” will be on, and the generator will enter into frequency
modulation function.
4.6.1 Modulation frequency:
Press【Menu】key to light “Mod_f” character, and then set modulation frequency value. In FM, modulation
frequency is usually far lower than carrier frequency.
4.6.2 Frequency deviation:
Press【Menu】key to light “Devia” character, and then set frequency deviation value. Frequency deviation
represents the frequency variation of carrier wave when the modulating waveform is with full amplitude
during FM process. When the amplitude of the modulating waveform is at positive peak value, the output
frequency is equal to the frequency of the carrier plus the frequency deviation, and when it is at the negative
peak value, the output frequency is equal to the carrier frequency minus the frequency deviation. Therefore,
the frequency deviation setting must conform to the following two conditions:
（Carrier frequency－frequency deviation）＞0
（Carrier frequency＋frequency deviation）＜The upper limit of the generator
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