BURSt Subsystem
BURSt Subsystem
This section describes the BURSt subsystem.
Example
This summarizes the steps required to generate a burst.
1.
Configure the burst waveform:
Use
or the equivalent
,
, and
commands to select the waveform's function, frequency, amplitude, and offset. You can select a sine,
square, triangle, ramp, pulse, PRBS, or arbitrary waveform (noise is allowed only in the gated burst mode and DC is
not allowed). For internally-triggered bursts, the minimum frequency is 2.001 mHz. For sine and square wave-
forms, frequencies above 6 MHz are allowed only with an "infinite" burst count.
2.
Select the "triggered" or "gated" burst mode:
Select the triggered burst mode (called "N Cycle" on the front
panel) or external gated burst mode using
. If you are using gated mode, specify true-high or true-
low logic with
.
3.
Set the burst count:
Set the burst count (number of cycles per burst) to any value between 1 and 100,000,000
cycles (or infinite) using the
command. Used in the triggered burst mode only. In PRBS,
sets the number of bits of PRBS. Each burst starts at the sequence start.
4.
Set the burst period:
Set the burst period (the interval at which internally-triggered bursts are generated) to
any value from 1 μs to 8000 seconds using
. Used only in the triggered burst mode with an
internal trigger source.
5.
Set the burst starting phase:
Set the starting phase of the burst from -360 to +360 degrees using
.
6.
Select the trigger source:
Select the trigger source using the
command. Used in the trig-
gered burst mode only.
7.
Enable the burst mode:
After configuring the other burst parameters, enable the burst mode (
).
Burst Modes
There are two burst modes, described below. The instrument enables one burst mode at a time.
l
Triggered Burst Mode (default):
The instrument outputs a waveform for a number of cycles (burst count)
each time a trigger is received. After outputting the specified number of cycles, the instrument stops and waits for
the next trigger. You can configure the instrument to use an internal trigger to initiate the burst or you can pro-
vide an external trigger by pressing the front-panel
Trigger
key, by applying a trigger signal to the rear-panel
Ext
Trig
connector, or by sending a software trigger command from the remote interface.
l
External Gated Burst Mode:
The instrument output is either "on" or "off" based on the level of the external sig-
nal applied to the rear-panel
Ext Trig
connector. When this signal is true, the instrument outputs a continuous
waveform. When this signal goes false, the current waveform cycle is completed and then the instrument stops
while remaining at the voltage corresponding to the starting burst phase of the waveform.
The following table shows which modes are associated with which burst features.
Burst Mode
Burst Count
Burst Period
Burst Phase
Trigger Source
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Agilent 33500 Series Operating and Service Guide
