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IM 701240-01E
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App
Index
Explanation of Functions
2.6
Waveform Computation
Various computations can be performed on up to 800 kW of data on the SL1400. (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 «For procedures, see section 10.1.»
Addition, subtraction, multiplication, and division can be performed between two arbitrary
waveforms of CH1 to CH16 and Math1 to Math7. 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 to
be computed
Computed
waveform
Binary Computation «For procedures, see 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 «For procedures, see 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
The following three FFT windows are available.
Rectangular (Rect)
The rectangular window is best suited to transient signals, such as impulse waves, 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 compared to
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.