Generating Arbitrary Waveforms; What Are Arbitrary Waveforms; Arbitrary Memory Management - Racal Instruments 3151 User Manual

Generating
Arbitrary
Waveforms
What Are Arbitrary
Waveforms?
Arbitrary Memory
Management
Memory
Using The Instrument 3-24
The Model 3151/3151A cannot generate arbitrary waveforms without
first loading them into memory. A description of the arbitrary
waveform function and an explanation on how to load waveforms into
memory is given in the following paragraphs.
Arbitrary waveforms are generated from digital data points which are
stored in memory. Each data point has vertical resolution of 12 bits
(4096 points), i.e., each sample is placed on the vertical axis with a
precision of 1/4096.
Arbitrary waveform memory has the capacity to store up to 512K of
horizontal data points (64K for the –001 version of the 3151). Each
horizontal point has a unique address - the first being 00000 and the
last 64435. In cases where smaller wavelengths are required, the
Model 3151/3151A's waveform memory can be divided into smaller
segments. Then it is possible to select which segment is sampled,
how many times and in what sequence.
When the instrument is programmed to output arbitrary waveforms, a
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. The Model 3151/3151A provides
programmable sample clock rates from 100 mHz to 100 MHz.
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.
The Model 3151A's arbitrary memory consists of a fixed length of
524288 words (65,536 for Model 3151-001 version). 1K is always
reserved for the built-in standard waveforms. The maximum size
arbitrary waveform that can be loaded into memory is 523288 points
long. It is not always necessary to use the complete length of this
memory. The memory can be partitioned into smaller segments and
different waveforms can be loaded into each segment. The memory
can be partitioned into 4096 segments, each having a unique length
and identity. Minimum segment length is 10 points. Information on
how to partition the memory is given in the following paragraphs.
Arbitrary memory can be divided into smaller segments; up to 4096
different arbitrary waveforms can be generated with the Model
3151 And 3151A User Manual