Siemens SIMATIC IOT2000 Series, Руководство по эксплуатации

Страница: 23 / 38

6.6 Low-pass filter cut-off frequency
There is a critically damped low-pass filter for suppressing faults. The diagram below shows the
step response of the filter (f = 2 Hz). The entry "0" means that the filter is switched off. A cut-off
frequency between 0.05 and 20.0 Hz can be specified.
Figure 6-2 Step-forced response of the digital low-pass filter when f = 2 Hz
The definition of the cut-off frequency is extremely important for the suppression of faults.
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 scales "slower".
6.7 Ordinal number 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 filter number, the higher the effect.
6.8 Mean value filter depth
The mean value filter is used to steady the weight against random interference. The weight is the
mean value of n (n = max. 250) weights which are recorded by the weighing module every
10 ms, e.g. when n = 10, the mean of 10 weights is calculated. Every 10 ms, the oldest value is
discarded and the newest value included in the calculation.
Parameter assignment
6.8 Mean value filter depth
SIMATIC IOT2000 SG-Shield
Operating Instructions, 08/2021, A5E50985404-AA
23