Frequency Low Pass Filter Weight/Belt Load/Belt Speed; Order No Low Pass Filter; Depth Average Filter Flow Rate - Siemens SIWAREX WP241 Manual

Scale parameters and functions of the belt scale
8.8 DR 6 Limits
8.8.13

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
switched off. The cut-off frequency can be specified between 0.05 and 50.0 Hz.
Figure 8-1
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".
8.8.14

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.
8.8.15

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.
96
Step response of the digital low-pass filter when f
= 2 Hz). The entry "0" means that the filter is
g
= 2 Hz
g
SIWAREX WP241
Manual, 04/2014, A5E33713528A