Application
Applications using the low-cost absolute value encoder of the Stegmann company.
Function description
Besides the Stegmann encoder (type SCM70) the following additional Hiperface sine/cosine absolute value encoder types can be parameterised without inserting new codes or additional selection options in existing codes:
Number of pulses per revolution
[Periods/rev] | Data format
[inc/rev] | Encoder type |
| 2048 | 2^16 | not available on the market |
| 1024 | 2^15 | Stegmann SRM50, SRS50 |
| 512 | 2^14 | Stegmann SCM70/60, SCS70/60, Standard |
| 256 | 2^13 | not available on the market |
| 128 | 2^12 | Stegmann SKS36 |
| 64 | 2^11 | not available on the market |
The encoder initialisation is adapted to the different encoder data formats by means of the number of pulses per revolution (C0420). When entering the above mentioned discrete number of pulses per revolution the data format is observed as listed in the table above during the initialisation. The data format (inc/rev) determines the reachable resolution of the initialised absolute value encoder.
Procedure to set the Hiperface absolute value encoders used:
1. Set C0025 'encoder selection' if only one encoder is available or set C0490 'feedback system position' if the absolute value encoder is used as position encoder only.
All single-turn types: C0025 = 310 (AS512-8V); C0490 = 3 (Absolute-ST)
All multi-turn types: C0025 = 410 (AM512-8V); C0490 = 4 (Absolute-MT)
and
afterwards (!):
2. enter the number of pulses per revolution under C0420 if it deviates from 512 number of pulses per revolution
3. set the encoder voltage supply to 8 V under C0421
It is very important that this order is adhered to since otherwise C0420 is overwritten by the encoder selection.
Compatibility:
Only if the above mentioned number of pulses per revolution are selected the under C0420 the initialisation changes as described before. In case of all other numbers of pulses per revolution the behaviour does not change.
Behaviour of previous versions:
Up to now it was only possible to use Hiperface absolute value encoders with 512 numbers of pulses per revolution. It was possible to adapt other encoder numbers of pulses per revolution under C0420 but the data format of the serial transmitted absolute value was not adapted either. As a result, the actual position value and the rotor position (C0060) were always initialised incorrectly.
