Configure

Notice

Invalid measured values with activated filters

If one or more filters are activated and the sampling rate is not in the factory setting, invalid measured values may be output.

  • Make sure that the measured value filters of all channels are disabled before setting a sampling rate unequal to 4 kHz.
    See chapter Measured value filter.

Up to and including firmware 02, you cannot set the sampling rate.

From firmware 03, you can set the sampling rate in parameter F800:0D "Sampling rate".

Configure 1:

By setting the sampling rate, you also influence the cut-off frequency of the integrated low-pass filter, which is used to pre-filter the measured values. This low-pass filter cannot be disabled.

The following table shows the possible values for the sampling rate, the associated cut-off frequency of the low-pass filter and the maximum EtherCAT cycle time recommended in each case.

Value

Sampling rate

3 dB cut-off frequency of the low-pass filter

Recommended maximum EtherCAT cycle time

0 (default)

4000 Hz

1000 Hz

250 µs

2

1000 Hz

250 Hz

1 ms

4

250 Hz

62.5 Hz

4 ms

6

62.5 Hz

15.625 Hz

16 ms

10dec

3.906 Hz

0.977 Hz

256 ms

Ensure that the recommended maximum EtherCAT cycle time for the set sampling rate is not exceeded. If necessary, reduce the sampling rate or the EtherCAT cycle time of the controller. This prevents measuring errors due to aliasing effects.

Influence of the sampling rate on the measured value noise

The measured value noise decreases with lower sampling rate.