Sampling-Rate (ODR)
The sampling rate specifies how often the box provides an updated measured value for the controller.
You can set the sampling rate in parameter F800:0D “Sampling rate”. Factory setting: "4000 Hz".
This parameter applies to all six measuring axes. An individual setting for individual axes is not possible.
The sampling rate setting also influences the following factors:
- The measured value noise. The lower the sampling rate, the lower it is.
(prerequisite: the maximum EtherCAT cycle time specified below is observed) - 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 recommended maximum EtherCAT cycle time.
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 (ODR) | 3 dB cut-off frequency of the low-pass filter | Recommended maximum EtherCAT cycle time (For operation without oversampling) |
|---|---|---|---|
0 | 4000 Hz | 1000 Hz | 250 µs |
1 | 2000 Hz | 500 Hz | 500 µs |
2 | 1000 Hz | 62.5 Hz | 1 ms |
3 | 200 Hz | 100 Hz | 5 ms |
4 | 100 Hz | 100 Hz | 10 ms |
255 | "Auto" 1) | According to the automatically selected sampling rate. | Variable. The sampling rate adapts to the cycle time. |
1) With the value "Auto", the sampling rate automatically adapts to the EtherCAT cycle time.
If the sampling rate is not set to “Auto”, ensure that the recommended maximum EtherCAT cycle time for the set sampling rate is not exceeded during operation without oversampling. If necessary, reduce the sampling rate or the EtherCAT cycle time of the controller. This prevents measuring errors due to aliasing effects.