Svantek SVAN 958A - Page 149

149
SVAN 958A User Manual
2..13
FFTHeader[1]
header of the first enabled FFT analysis, defined
in the case of SLM mode - in Table B.1.8_SLM and
in the case of VLM mode - in Table B.1.8_VLM
…
…
…
2+spectrum
_count*12..
13+spectru
m_count*12
FFTHeader[spectrum_c
ount]
header of the last enabled FFT analysis, defined
in the case of SLM mode - in Table B.1.8_SLM and
in the case of VLM mode - in Table B.1.8_VLM
reserved
reserved
…
…
…
Table B.1.8_SLM. Header of the FFT analysis in one-channel SLM mode
Word
number
Name / Value
Comment
0
0xnn0C
[0C, nn=block_length]
1
FFTChannel
channel of FFT analysis
2
FFTFilter
FFT analysis filter: 0 - HP, 1 - LIN, 2 - A, 3 - C
3
FFTBuff
FFT logging: 0 - OFF, 4 - RMS
4
LowestFreqNo
number of the first line in the FFT spectrum = 0
5
NFft
number of lines in the spectrum = 1921, 961 or 481
6
NFftTot
number of TOTAL lines in the spectrum = 1
7
FftBand
band of the FFT analysis: 1 - 22.4 kHz, 2 - 11.2 kHz, 3 - 5.6 kHz,
4 - 2.8 kHz, 5 - 1.4 kHz, 6 - 700 Hz, 7 - 350 Hz, 8 - 175 Hz,
9 - 87.5 Hz
8
FftWindow
window in the FFT analysis: 0 - HANNING,1 - RECTANGLE,
2 - FLAT TOP, 3 - KAISER-BESSEL
9
FftAverag
type of averaging in the FFT analysis: 0 - LINEAR
10..11
FftSampFreq
sampling frequency
12
FftWFactor
window coefficient
13
FftLines
number of lines: 0 - 1920 lines, 1 - 960 lines, 2 - 480 lines
14
FFTCounter
number of averaged FFTs
…
…
…
Table B.1.8_VLM. Header of the FFT analysis in one-channel VLM mode
Word
number
Name / Value
Comment
0
0xnn0C
[0C, nn=block_length]
1
FFTChannel
channel of FFT analysis
2
FFTFilter
FFT analysis filter: 0 - HP, 3 - 2nd profile filter
3
FFTBuff
FFT logging: 0 - OFF, 4 - RMS
4
LowestFreqNo
number of the first line in the FFT spectrum = 0
5
NFft
number of lines in the spectrum = 1921, 961 or 481