TEST & MEASUREMENT
Figure 2. Waveform memory splitting and sequence memory linking
form memory will be replayed once after each
• Repetitive (continuous) - data from the waveform
memory is played continuously a programmed
number of times or until a stop
command is issued.
• Gated – allows the waveform output to be
controlled by the
state of an external
• Multiple – Memory
is divided into segments
of the same
length. One segment
is output per
• Sequence – Memory
is divided into
lengths are loaded
into the segments.
A sequence file
determines the order
of output, loop
count, and segment
to be output.
Multiple and sequence
segment the waveform
memory with each segment
containing one waveform or part of a
waveform. Each trigger then advances the segment
number and outputs the selected waveform.
The sequence mode adds the ability to
loop the segment contents for a user-selectable
number of times as well as selecting the next
segment to be output.
The whole sequence process is explained in
Figure 2. The sequence mode, as mentioned
previously, segments the AWG waveform into
several data segments.
Each of the waveforms loaded in each segment
can be of a different size. The data segments
are linked in a user chosen order using
an additional sequence memory, as shown at
the bottom of Figure 2. The sequence memory
links the memory step with a specific segment,
specifies the number of loops for each segment,
and defines the next segment. Importantly,
the switching between waveform segments
occurs with no dead time between segments.
The authors continue with more details of an
example of using the sequence mode of the
AWG, illustrating the flexibility it offers in a realistic
test scenario. Click the panel below for full
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30 DesignNews NOVEMBER 2017 www.eedesignnewseurope.com