Racal Instruments 3152A, Руководство пользователя

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3152A User Manual
Using The Instrument 3-26 Racal Instruments
©
2001
What Are
Arbitrary
Waveforms?
Arbitrary waveforms are generated from digital data points that
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. Each horizontal point has a unique
address - the first being 00000 and the last being 523,287. In
cases where smaller wavelengths are required, the Model
3152A'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 3152A provides programmable sample clock rates from
100mHz to 100MHz.
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 arbitrary waveform
memory is given in the following paragraphs.
Arbitrary Memory
Management
The Model 3152A's arbitrary memory consists of a fixed length of
524,288 words. 1000 words are always reserved for the built-in
standard waveforms. The maximum size arbitrary waveform that
can be loaded into memory is 523,288 points long. It is not
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.