Measured value filter

Enable filter

The digital filter is enabled in the factory setting: parameter 0x80A0:06 "Enable filter" is TRUE.

To disable the filter, set index 0x80A0:06 "Enable filter" to FALSE.

Select filter type

You can set the filter type in parameter 0x80A0:15 “Filter settings”.

Descriptions of the behavior of the two filter types can be found in the sections FIR filter and IIR filter.

Conversion time

The conversion time is the time interval between the points in time at which the box provides a new measured value.

The conversion time and the trigger mode depend on the following factors:

• Configuration of the filters.
• Setting the synchronization mode in CoE parameter 0x1C33:01:
• By manually parameterizing in the System Manager.
  (Recommendation: enter the settings in the startup list, otherwise they will be lost in the event of a voltage reset.)
• By making an entry in the startup list.
  (Note: The entries in the startup list are only executed when the configuration is enabled.)

FIR filter (Finite Impulse Response)

The FIR filters are non-recursive notch filters. A notch filter has zeros (notches) in its frequency response at the filter frequency and multiples of the filter frequency. These frequencies are therefore attenuated in amplitude.

If an FIR filter is enabled, it determines the conversion time: the higher the filter frequency, the faster the conversion time.

Example of a typical attenuation curve of a notch filter with 50 Hz filter frequency:

Filter data

IIR filter (Infinite Impulse Response)

The IIR filters are low-pass filters. They can be set in eight levels:
From level 1 = weak filter to level 8 = strong filter.

With the synchronization mode “Free Run”, the filter operates with an internal cycle time of 500 µs.