4.5. Burst function
It is explained that in burst mode, the word “burst” means the cycle of any waveform, not only the pulse.
In burst output, instrument outputs a waveform with a specified number of cycles and at a specified period
at a starting phase, or it outputs a waveform with a specified number of cycles only single once. All the 16
waveforms could be used as burst waveform, Of course, using DC or noise signal as burst signal is
invalid. Before entering burst function, users should set the waveform, frequency and amplitude of the
burst under the continuity function.
Press
【
Burst
】
key to light “Burst” keyboard indicator, the generator will enter into burst function.
4.5.1. Repeated Period:
Press
【
Menu
】
key to light “Period” character, and then set repeated period. Period represents time from
the start of one pulse string to the start of the next one which must be long enough to contain the pulse
numbers of setting, as the following formula shows:
Repeated period
＞
Pulse count ÷ Pulse frequency
If the repeated period setting is too short, the instrument will modify it to the allowable minimum value.
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.
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