CiDRA Use of Foundation Fieldbus Protocol with SONARtrac Transmitters User Manual
Page 24

Table 3 Transducer Block Configurations (Page 11)
SOS_TOTAL_DATA
Unsigned
Long
R/W
Calculates SOS Samples from this value and SOS
Sample Frequency: SOS Samples = SOS Total Data *
SOS Sample Freq.
SOS_WINDOW_SIZE
Unsigned
Long
R/W
Number of FFT points to use in SOS calculation.
Usually set to 1/8 or 1/4 of the sample frequency
SOS_WINDOW_OVERLAP
Unsigned
Long
R/W
Number of sample point overlap between successive
FFTs. Recommended to set this to 50% of
SOS_FFT_POINTS.
SOS_SUB_ARRAY_SIZE
Unsigned
Long
R/W
SOS Sub Array Size
SOS_NORMALIZATION
Unsigned
Long
R/W
0 selects NO normalization in the frequency domain. 1
selects normalization in the frequency domain.
SOS_DIFFERENCING
Unsigned
Long
R/W
0 selects NO differencing in the frequency domain. 1
selects 1st order differencing in the frequency domain. 2
selects 2nd order differencing in the frequency domain.
SOS_OPERATING_MODE
Unsigned
Long
R/W
Determines which ridge to use for SOS calculation. Also
determines which SOS parameter to leave fixed or
calculate and whether or not to use Linear/Log KW diff.
Bit Mapped Values: 0: Use right and left ridge averaged
1: Use right ridge only 2: Use left ridge only 4: Enable
SOS auto frequency calculation 8: Enable SOS power
weighting to auto frequency calculation 16: Linear KW
diff enable 32: Log KW diff enable.
SOS_SELECTION_THRESHOLD
Unsigned
Long
R/W
SOS Selection Threshold
SOS_MIN_FREQ_POINTS_(AUTO_FREQ)
Unsigned
Long
R/W
This value selects the minimum number of frequency
points that will be used in the SOS calculation. If this
number is not met then the calculation is not performed
and an error is reported.
SOS_ALGORITHM_DYNAMIC
SOS_VALID_FREQ_PTS_RIGHT
Unsigned
Long
R
The number of frequency points used from the right
ridge of the k-w plot.
SOS_VALID_FREQ_PTS_LEFT
Unsigned
Long
R
The number of frequency points used from the left ridge
of the k-w plot.
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