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2-47
IM 701210-05E
Explanation of Functions
2
2.6
Waveform Computation
Various computations can be performed on up to 800 kW of data on the DL750/DL750P.
(If a waveform greater than 800 kW is displayed, computation cannot be performed over
all the data at once.) The computed results become Math1 to Math8 waveforms.
Addition, Subtraction, Multiplication, and Division <Section 10.1>
Addition, subtraction, multiplication, and division can be performed between two arbitrary
waveforms of CH1 to CH16 and Math1 to Math8. These computations are useful in the
following cases.
Addition and subtraction:
Comparison with the standard signal, confirmation of the
signal logic, phase comparison, etc.
Multiplication and division:
Confirmation of the power waveform by applying the voltage
and current signals, etc.
–Computation
waveform
+Computation
waveform
×
Computation
waveform
Waveform on
which to perform
computation
Computation
waveform
Binary Computation <Section 10.2>
The specified waveform is converted to a digital waveform of 0s and 1s with respect to
the specified threshold level. The computation can be performed on CH1 to CH16 and
Math1 to Math7.
Power Spectrum Display <Section 10.3>
The power spectrum of the input signal can be displayed by taking the FFT (Fast Fourier
Transform). This is useful when you wish to check the frequency distribution of the input
signal.
Power spectrum waveform
You can select the FFT window from the following three types.
Rectangular (Rect)
Best suited to transient signals, such as an impulse wave, which attenuate completely
within the time window.
Hanning and FlatTop
The Hanning and flattop windows allow continuity of the signal by gradually attenuating
the parts of the signal located near the ends of the time window down to the 0 level.
Hence, it is best suited to continuous signals. With the Hanning window, the frequency
resolution is high as compared with the flattop window. However, the flattop window has
a higher level of accuracy. When the waveform being analyzed is a continuous signal,
select the proper window for the application.