User manual

Table Of Contents
3152B User Manual Publication No. 980935 Rev. M
3-26 Operation Astronics Test Systems
Generating
Sequenced
Waveforms
Sequences are comprised of
waveform segments that reside in the
waveform memory
. The sequence generator lets you link and loop
segments in a user-defined order. To avoid unexpected results, i
t is
essential that waveform segments are pre-loaded into
waveform
memory before a sequence table is used.
To create a waveform sequence, you will create a sequence table
that provides instructions to the sequencer for assembling
the
waveform from the segments in the waveform memory. Figure 3-
2
shows an example of a sequence table
created using
ArbConnection. The sequence table has five fields for each step:
Link
This defines the step number. The sequence will advance
through the links in the same order in which they are entered. There
are no pauses or transitions between links.
Seg This defines the waveform
segment number that will be
linked to form the next part of the sequence. The order of
waveform
segments in waveform memory is irrelevent
. You may link them in
any order.
Loops This defines the number of times the seg
ment will repeat
itself before advancing to the next link, or step.
The number of loops
may range from 1 through 1,048,576.
Adv Defines the advance bit
, which tells the generator whether to
move to the next link immediately or to hold and wait for a trig
ger
event before moving to the next link.
The various advance modes
are discussed in more detail in another section.
Sync This specifies the link on which
you want to place a
synchronization bit. The SYNC output must be switched to the B
it
source option to enable the use of this feature. The
Normal SYNC
output is LCOM, where the output goes high at the beginning of the
sequence and returns to low at the end of the sequence.
The following paragraphs describe the commands that create
,
delete, update, and modify sequence tables.