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O
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M
PERATOR
S
ANUAL
How Does this Work?
The amplitude of the signal is about 0.3 volts, and the screen height is 0.4 volts, as derived from cells F7 and Fx.
A threshold value for amplitude was calculated by placing 0.5 * (Fy – Fx) in cell A4.
Remember that in the instrument the sources were defined to be A10 and B10. This means that the first point on
the waveform will be read into A10, and, since the waveform has 500 points, the last point will be read into A510.
The same holds true for F2 and column B, since F2 is assigned as Source2, and data is defined to write into
column B starting with cell B10.
To create the gating function in column C, the cell C10 was given the following formula:
IF ( ( B10 – B9) > $A$4, 1 – C9, C9). This was copied down the column. Column D, the output column, is
simply A * C.
The output was defined as cell H3.
The required mean in cell H3 is given by SUM (D10 : D509) / SUM (C10 : C509), for a 500 point waveform.
Correlation Excel Waveform Function (Excel Example 3)
This example uses an Excel waveform function to examine the cross-correlation between two signals, which are
both noisy sinusoidal segments. The correlation trace is, of necessity, shorter than the input traces.
The noise was generated using pseudo-random numbers. Randomize Timer was included in the VBScript to
ensure that the two traces differed, and that subsequent acquisitions differed. Functions F1 and F2 are included
only to simulate signals, and are not part of the measurement process, which is performed by F3.
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WRXi-OM-E Rev C
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