Communication
11.9 DR 6 Limits
SIWAREX WT241
124 Manual, 05/2015, A5E36046748A
11.9.13 Frequency low pass filter weight/belt load/belt speed
A critically damped low-pass filter is provided to suppress interferences. The diagram below
shows the step response of the filter (f
g
= 2 Hz). The entry "0" means that the filter is
switched off. The cut-off frequency can be specified between 0.05 and 50.0 Hz.
Figure 11-1 Step response of the digital low-pass filter when f
g
= 2 Hz
The definition of the cut-off frequency is extremely important for suppressing interferences.
Defining the cut-off frequency defines the "speed" of the scale's response to changes in the
measured value. A value of 5 Hz, for example, results in a relatively rapid response to a
change in weight; a value of 0.5 Hz makes the scale "slower".
11.9.14 Order no low pass filter
The number of the filter defines the effect of damping. The values 2, 4, 6, 8, and 10 can be
set. The higher the selected order number, the higher the damping effect of the filter.
11.9.15 Depth average filter flow rate
The mean value filter is used to steady the weight against random interference. The weight
is generated from the mean value of n (n = max. 250) weight values calculated by the
weighing module every 10 ms. With n = 10, for example, 10 values are used to generate the
mean value. The oldest value is discarded every 10 ms, and the newest value included in
the calculation.