Operation with modulo
In the case of operation with a modulo, the following properties are brought to bear:
- 1. The range of the multi-turn encoder is subdivided into four large ranges
- Range of the multi-turn encoder = 4096 revolutions
- One quarter range = 1024 revolutions
- 2. Saving procedure
- On each transition from one quarter range to another, the modulo data set is modified and saved in the servo drive (real position and CRC)
- The servo drive always has two modulo data sets saved. These data sets are used in alternation.
- A modulo data set is also saved if the EtherCAT state changes from SaveOP to PreOP.
- 3. Power-on procedure
- Both modulo data sets are read if the EtherCAT transition changes from Boot to Init. The last valid data set is used to reconstruct the modulo position.
- 4. Power supply error (uncontrolled voltage drop of the 24 V supply)
- Under certain circumstances it may no longer be possible to save a data set because the 24 V supply has been interrupted. Because two data sets exist at all times, however, one of them is valid and can be used to reconstruct the modulo position at the next power-on.
- 5. Maximum speed during operation with modulo
- Since the saving of the modulo data sets in an internal persistent memory in the AX5000 cannot take place at an infinitely fast speed, the motor speed is limited. An example of the calculation of the maximum possible speed can be found in the section Maximum possible speed.