Filter

The measured value of each input channel can be filtered with a digital filter.

Enable filter

Note

Measured value jumps when enabling or disabling filters

When filters are enabled or disabled, short-term measured value jumps can occur in the process data that do not correspond to the physical values.

You can enable the filter individually for each input channel. All filters are disabled in the factory setting.
Enable the filters by setting the following CoE parameters to TRUE:

Input channel		CoE parameters for enabling the filter
1	Control voltage U_S	8000:01 "Enable filter"
2	Peripheral voltage U_P	8010:01 "Enable filter"

Select filter characteristic

You can select the filter characteristic individually for each input. Factory setting: "50 Hz FIR".

Input channel		CoE parameter for selecting the filter characteristic
1	Control voltage U_S	8000:19 "Filter characteristic"
2	Peripheral voltage U_P	8010:19 "Filter characteristic"

There is a choice of two filter types:

FIR filter

The filter works as a notch filter and determines the conversion time of the module. The higher the filter frequency, the faster the conversion time. A 50 Hz and a 60 Hz filter are available.
Notch filter means that the filter has zeros (notches) in the frequency response at the filter frequency and multiples thereof, i.e. it attenuates the amplitude at these frequencies.

The FIR filter operates as a non-recursive filter.

IIR filter

The filter with IIR characteristics is a discrete time, linear, time invariant filter that can be set to eight levels (level 1 = weak recursive filter, up to level 8 = strong recursive filter)
The IIR can be understood to be a moving average value calculation after a low-pass filter.