CiDRA Passive Sonar Transmitters - Manual (Page 41)

Table 5 Modbus Holding Registers (continued)
Address Size Type Value Description Values
4519 2 Long
TRANSIT_TIME_MU
LT
Default values are normally OK. Define target number of
passes through array per calculation for volumetric flow.
Use with caution.
4521 2 Long
VF_PEAK_SEARCH
_MODE
0 = No differencing, 1 = difference sensors using first
order differencing. (i.e. Ch1=S1-S2* Ch2=S2-
S3...Ch7=S7-S8). 2 - second order differencing (i.e.
Ch1=S1-2*S2+S3* Ch2=S2-2*S3+S4...).
4523 2 Long
VF_OP_MODE_SET
TINGS
0 = Dynamic frequency adjust in auto runmode (original
calculation), 1 = Fixed frequency in auto run mode, 2 =
Fixed blocks in auto run mode, 4 = Dynamic Nyquist
calculation enable, 8 = Reserved for future use, 16 =
Linear KW diff enable, 32 = Log KW diff enable.
4525 2 Long
VF_QUALITY_MOD
E 0 = original VF quality calculation, 1 = new VF quality
calculation.
4527 2 Long NUM_BLOCKS Define number of blocks used for calculations.
4529 2 Long NFFT
Number of points used in FFT. Actual FFT size is next
2^n higher value. Value of NFFT is zero padded to next
larger 2^n FFT size. This value is normally set by the
DSP.
4531 2 Long
WINDOW_OVERLA
P Define overlap of FFT windows. This value is normally
set by DSP to half of NFFT.
4533 2 Long FFT_AVGS
Default values are normally OK. In general for slower
flow rates use more FFT averages; for faster flow rates
use fewer FFT averages. This parameter affects the
number of blocks used (there is a 20 block maximum
due to DSP memory limitations). Use with caution.
4535 2 Long SOS Total Data
Calculates SOS Samples from this value and SOS
Sample Frequency: SOS Samples = SOS Total Data *
SOS Sample Freq.
4537 2 Long SOS_FFT_POINTS
Number of FFT points to use in SOS calculation. Usually
set to 1/8 or 1/4 of the sample frequency.
4539 2 Long
SOS_WINDOW_OV
ERLAP
Number of sample point overlap between successive
FFT's. Recommended to set this to 50% of
SOS_FFT_POINTS.
20959-01 Rev 02 Page 3-26