Scaime eNod4-B - Limitations; Band-Stop Filter High Cut-Off Frequency; Band-Stop Filter Low Cut-Off Frequency; Moving Average Weight Filter Depth

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User manual SCAIME: NU-soft-eNod4B-E-0716_236704-C.doc
12.3.4 Limitations
Recursive filters like eNod4 low-pass filters are computed according to the filter order, the desired cut-off frequency
and the sampling rate. There are some limitations to respect in order to ensure a safe functioning of the signal
processing. They are listed in the table below:
A/D conversion rate
(meas/s)
min low-pass cut-off frequency
(Hz)
A/D conversion rate
(meas/s)
min low-pass cut-off frequency
(Hz)
50 Hz rejection
60 Hz rejection
2nd order
3rd order
2nd order
3rd order
6.25
0.10
0.10
7.5
0.10
0.10
12.5
0.10
0.10
15
0.10
0.15
25
0.10
0.15
30
0.15
0.20
50
0.15
0.25
60
0.20
0.30
100
0.25
0.50
120
0.30
0.60
200
0.50
1.00
240
0.60
1.20
400*
1.00
2.00
480*
1.20
2.40
800
2.00
4.00
960
2.40
4.80
1600
4.00
8.00
1920
4.80
9.60
(*) In belt mode, A/D conversion rate is fixed to 400 meas./s and cannot be modified.
12.3.5 Band-stop filter high cut-off frequency
This register contains the band-stop filter high cut-off frequency expressed in Hz and multiplied by 100. That means
that 690 is equivalent to 6.90 Hz. The value must be higher than the band-stop filter low cut-off frequency.
Admitted values: from 10 up to 20000.
12.3.6 Band-stop filter low cut-off frequency
This register contains the band-stop filter low cut-off frequency expressed in Hz and multiplied by 100. That means
that 690 is equivalent to 6.90 Hz. The value must be lower than the band-stop filter high cut-off frequency.
Admitted values: from 10 up to 20000.
12.3.7 Moving average weight filter depth
This filter can be set in cascade after previous filters. The Moving average filter is used to smooth the weight value in
case of random interferences. This sliding average computes the mean of the ‘n’ last measures which are output of
the previous filters, if enabled. A high filter depth will give a better stability, with a longer response time.
Filter depth admitted values: 0(disabled) up to 128.
12.3.8 Moving average flow rate/speed filter depth
Specific average filter might be applied on belt process data to have stable display. A high filter depth will give a better
stability, with a longer response time.
Filter depth admitted values: 0(disabled) up to 128.