To calculate the characteristic values, DIN EN 61000-4-7 dictates an anti-aliasing filter to suppress high-frequency interference that would corrupt the calculation of the harmonic components. A digital anti-aliasing filter with a cut-off frequency of approx. 3 kHz is implemented. This filter is also used for the raw values recorded with ibaPDA.

ibaPQU-S activates this anti-aliasing filter with the signals used for characteristic value calculation or as synchronization signal. The configuration of these signals in ibaPDA is ignored in this process.

Signals not used for characteristic value calculation are not changed and the settings in ibaPDA are active.

The following table shows the filter effect:

Signal used for characteristic value calculation

Inputs

Filter (cut-off frequency fc)

Delay

Total

yes

AnalogU / I

Analog filter with fc=12 ... 25 kHz and digital filter with fc=3 kHz

approx. 0.3 ms

no

Analog

None*

0

Analog filter with fc=12...25 kHz*

0.04 to 0.08 ms

Analog filter with fc=12...25 kHz

and digital filter with adjustable fc*

Depends on fc

no

Digital

None or debouncing in mode "stretch rising/falling edge” or “stretch both edges”*

0

Debouncing in mode “delay both edges”*

Set debounce time in µs

* Setting in ibaPDA