3156B User Manual
Racal Instrument © 2005
Using the Instrument 3-27
Sequence
Commands
The following is an overview of how to define and program a sequence
of arbitrary waveforms.
A sequence is made of steps. 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 3156B is placed in Triggered mode, the
output will behave as it would in Burst mode where the repeat number
replaces the burst count parameter.
Aside from step numbers, each step has two other parameters:
segment number and repeat counter. The segment number specifies
which segment will be linked, and the repeat counter specifies how
many times the segment will loop.
The easiest way to create a sequence table is with WaveCAD. Using
this program you can define, create and download memory segments
to the instrument without thinking about low level commands, and then
use the sequence table to design a sequence. Regardless, it is
understood that not all can use WaveCAD and therefore, the only
other way to generate such sequence table is by using the following
function calls sequence:
Use the following function call repeatedly until you complete the table:
ri3156B_define_sequence_step
()
or, you can define the entire sequence table using the following
function call:
ri3156B_load_sequence_table
()
This function call has three variables:
Step number –
defines an index step in the sequence table
Segments array – provides an array of segments that will be
placed in the sequence table, and
Repeats array –
provides an array of repeats that are associated
with the segment and index number
Note that the same segment number can be used for different
sequence steps. These commands do not change the mode of
operations to sequence. The table will affect the 3156B only if you
change the waveform function to sequenced.