Specifications

User Manual 301/302
Sequenced
Waveforms
What Are
Sequenced
Waveforms?
Sequenced waveforms are made of a number of arbitrary waveforms,
which can be linked and repeated in user-programmable order.
Sequenced waveforms are generated from waveforms stored in a
library of memory segments (sequence table). Before using a
sequence of waveforms, load arbitrary memory with the required
waveforms. Use TRAC# or DMA methods to load waveforms into
memory. Information on how to partition the memory and load
waveforms is given in the section entitled Generating Arbitrary
Waveforms.
An example of how sequenced waveforms work is demonstrated in
figure 1.1a through 1.1d. The sequence generator lets you link and
loop segments in user-defined order. Figure 1.1d shows a sequence
of waveforms that were stored in three different memory segments.
To eliminate the need of downloading a new sequence table every
time you change your test setup, the 301/302 can store 16 different
sequences for you, each having a unique number of links and loops.
You can then use these sequences one at a time, or link them all to
one large sequence. Sequenced sequences are explained later.
Sequence
Commands
The following is an overview of how to define and program a
sequence of arbitrary waveforms.
A sequence is made of steps or links between segments. A step can
stand on its own or link to another step. It is possible to have only one
step in a sequence but the output will look like a continuous waveform.
If only one step is specified and the Model 301/302 is placed in
Triggered mode, the output will behave as in Burst mode, where the
repeat number replaces the burst count parameter.
You may download 16 different sequences to locations numbered
from 1 through 16. However, if you plan on using more than one
sequence you must first specify the maximum number of sequences
you intend to use and only then download sequence tables.
The number of sequences and the number of links in sequences are
inversely proportional. The more sequences you want to use, the less
number of links you can specify for each sequence. The following list
Configuring The Instrument
58