Mechanical cut-off frequency (0x80n1:19 “Mech. operating frequency”)
The input of the mechanical cut-off frequency via index 0x80n1:19 "Mech. Operating frequency" offers the option of signal filtering. A distinction is made here between
- free running filters (20 Hz ... 200 Hz) and
- Frame-triggered filters (synchronous level 1 ... synchronous level 8)
The free running filter does not run frame-synchronously to the EtherCAT cycle, but is calculated asynchronously in the product. A cut-off frequency can be specified for this.
The frame-triggered filter is called up synchronously with each EtherCAT cycle and therefore has a direct time reference that must be taken into account in calculations. Overshoots can occur due to the temporal jitter of the EtherCAT frame. The attenuation may be lower than with the free running filters.
![]() | Note Frame-triggered filters If EtherCAT cycle times in the range up to 300 µs are used, it is recommended to use the frame-triggered filter. Otherwise, signal step changes may occur due to duplicate or missing values. |
The following filter frequencies are available
Index 0x80n1:19 "Mech. operating Frequency" | |
|---|---|
Setting | Meaning: Cut-off frequency |
Filter disabled | Additional cut-off frequency filter is inactive, only internal filter 1 is active |
20 dec | 20 Hz |
30 dec | 30 Hz |
40 dec | 40 Hz |
50 dec | 50 Hz |
60 dec | 60 Hz |
80 dec | 80 Hz |
100 dec | 100 Hz |
200 dec | 200 Hz |
1001dec | Synchronous level 1, fg = 20 Hz * 100 µs / cycle time [µs] |
1002dec | Synchronous level 2, fg = 30 Hz * 100 µs / cycle time [µs] |
1003dec | Synchronous level 3, fg = 40 Hz * 100 µs / cycle time [µs] |
1004dec | Synchronous level 4, fg = 50 Hz * 100 µs / cycle time [µs] |
1005dec | Synchronous level 5, fg = 60 Hz * 100 µs / cycle time [µs] |
1006dec | Synchronous level 6, fg = 80 Hz * 100 µs / cycle time [µs] |
1007dec | Synchronous level 7, fg = 100 Hz * 100 µs / cycle time [µs] |
1008dec | Synchronous level 8, fg = 200 Hz * 100 µs / cycle time [µs] |
Fig.113: Filter characteristic curve free running filters
Fig.114: Filter characteristic Frame-triggered filters