Tabor Electronics 5251, User Manual

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TE5251
User Manual
4-28
Arbitrary
Waveforms
Control
Commands
This group is used to control the arbitrary waveforms and their
respective parameters. This will allow you to create segments and
download waveforms. Using these commands you can also define
segment size and delete some or all unwanted waveforms from
your memory. Use the commands in this group to turn the digital
output on and off and to download data to the digital pattern buffer.
Factory defaults after *RST are shown in the Default column.
Parameter range and low and high limits are listed, where
applicable.
Generating Arbitrary Waveforms
Arbitrary waveforms are generated from digital data points, which
are stored in a dedicated waveform memory. Each data point has a
vertical resolution of 16 bits (65536 points), i.e., each sample is
placed on the vertical axis with a precision of 1/65536. The Model
5251 has 2 M waveform memory capacity as standard.
Each horizontal point has a unique address - the first being 00000
and the last depends on the memory option. In cases where smaller
waveform lengths are required, the waveform memory can be
divided into smaller segments.
When the instrument is programmed to output arbitrary waveforms,
the clock samples the data points (one at a time) from address 0 to
the last address. The rate at which each sample is replayed is
defined by the sample clock rate parameter.
Unlike the built-in standard waveforms, arbitrary waveforms must
first be loaded into the instrument's memory. Correct memory
management is required for best utilization of the arbitrary memory.
An explanation of how to manage the arbitrary waveform memory is
given in the following paragraphs.
Arbitrary memory Management
The arbitrary memory in comprised of a finite length of words. The
maximum size arbitrary waveform that can be loaded into memory
depends on the option that is installed in your instrument. The
various options are listed in Chapter 1 of this manual. If you
purchased the 5251 with in its basic configuration, you should
expect to have 1 Meg words to load waveforms.
Waveforms are created using small sections of the arbitrary
memory. The memory can be partitioned into smaller segments (up
to 16k) and different waveforms can be loaded into each segment,
each having a unique length. Minimum segment size is 16 points.
Information on how to partition the memory, define segment length
and download waveform data to the 5251 is given in the following
paragraphs.
Table 4-4, Arbitrary Waveforms Commands Summary