Baumuller b maXX BM5800 - Page 701

Description of the Software Modules and Parameters
Parameter manual b maXX BM5800
Document No.: 5.16029.03
701
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104.21 FFT data
The result of the analysis is shown here as an Array parameter (dimension: 7 x 500). The
data is assigned as follows:
FFT Data[0]: Amplitude process in the dB
FFT Data[1]: Phase process in the degree
FFT Data[2]: Coherence
FFT Data[3]: Spectrum Signal_1, in the dB
FFT Data[4]: Spectrum Signal_2, in the dB
FFT Data[5]: Cross spectrum, real
FFT Data[6]: Cross spectrum, imaginary
The data accordingly contains the first 500 elements of the entire FFT-evaluation (starting
with the lowest frequency). The complete FFT-evaluation accordingly has (FFT length/2)-
elements. Thus the FFT results (104.21) include data up to a maximum frequency of:
Max. frequency [Z104.19–] x 500 x 2 / FFT length [Z104.9–]
Example:
An assumed RT0 cycle Z1.8– = 250 µs results in the "Max. frequency" Z104.19– =
2000 Hz. If "FFT length" Z104.9– = 4096, then the amplitude response covers values up
to 488 Hz.
104.22 Prbs register length
Length of the Prbs register.
104.23 Prbs register clock
Clock frequency of the Prbs register. Value corresponds to a whole multiple of the RT0
cycle.