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Appendix E: Functional Operation Summary
EĆ12
AWG2021 User Manual
4000
Points
Resolution
4000
4000
Points
Figure EĆ11: Relationship Between Triangular Wave Resolution and Number of Data
Points
For a triangular wave, extra waveform points beyond 8000 are meaningless. This
applies not only to triangular waves but to smooth waveforms, in general.
In normal use, this level of precision is rarely required. When it is not, the
number of waveform points may be reduced. In the equation editor and the
waveform editor, the default value for the number of waveform points is 1000.
When a sine wave is created with 1000 points, the size of this fold back
component is –60 dB, which should be no problem in ordinary use.
When making a waveform with less than 1000 points, because you are using the
maximum clock frequency, use a filter. In this case, observe the following points.
H According to sampling theory, if the ideal filter is used, with a mere two
points of data for the highest frequency component the waveform has, the
waveform can be reproduced. In order to eliminate overshoot and ringing,
the filters in the AWG2021 have Bessel characteristics with relatively gentle
shoulder characteristics. That is why more points are required.
H The amount of data required depends on the waveform shape, the S/N ratio
required, the filter cutoff frequency, and other such factors. Therefore, output
the waveform on the oscilloscope, spectrum analyzer, or the like, and check
that the waveform is what you need.
H Care is particularly necessary in creating waveforms with the equation editor.
When the Waveform Data Length is Not a Multiple of 8. Earlier, we explained that
only multiples of 8 can be set as the data length, but when the data length is
small, this becomes a problem.
When this instrument is used in Triggered mode, this problem is solved by
simply adding data at the end until the total length is a multiple of 8.