e
e
N
N
o
o
d
d
3
3
-
-
D
D
D
D
i
i
g
g
i
i
t
t
a
a
l
l
d
d
o
o
s
s
i
i
n
n
g
g
c
c
o
o
n
n
t
t
r
r
o
o
l
l
l
l
e
e
r
r
e
Nod3-
D
: User’s instructions
165 752-A
13/23
7.4 Feeding mode in dosing processes
For the filling and dosing by unloading functioning modes, it is possible to select the activation order of
the feed outputs :
coarse feed then fine feed after coarse feed stop
coarse feed + fine feed at the beginning of the cycle
coarse feed only
8
SET POINTS :
Set points are characterized by a high and a low value.
Their operating mode is either operating in hysteresis or operating in window.
The low and high values of these set points may be assigned either to (regardless of the functioning
mode) :
-
gross measurement
-
net measurement
9
FILTERS :
There are four available filtering levels :
∗
filtering related to the A/D conversion rate including rejection of the mains frequency (50 or
60 Hz) harmonics.
∗
2
nd
, 3
rd
or 4
th
order low-pass Bessel/Butterworth filter
∗
2
nd
order band-stop filter
∗
self-adaptive filter
- Filtering related to the A/D conversion rate : the signal resolution is related to the conversion rate.
The conversion rate might be choosen as low as possible, particularly for static applications. For dynamic
applications, a compromise must be found between the measurement rate and the low-pass filter cut-off
frequency. The
e
Nod
View
software can be used to determine appropriate filter values.
Choose a measurement rate that rejects the mains frequency harmonics according to the place of use, 50
or 60Hz.
- Bessel or Butterworth type low pass filter : a low-pass digital filter can be applied as an output of the
A/D converter. The filter order is configurable (available values are 2, 3 or 4) and the coefficients that
define it depend on the A/D conversion rate, the wanted cutt-off frequency and on the choosen order.
These coefficients can be easily calculated by
e
Nod
View
software.
- Band-stop filter : a 2
nd
order band-stop filter might be applied as an output of the low-pass filter (if
used) or the A/D converter. It allows to attenuate the frequencies within a band defined by a high and a
