For precise speed control in rolling mills the main drives as well as the roughing stand and coilers need to be equipped with an encoder. In addition, it is often necessary to provide increased protection for personnel during the following operating statuses:
- Safe standstill
- Safe limited speed
- Maintenance work on a live system
A sensible solution in this case is an overspeed switch that operates independent of the encoder and fulfils the special safety requirements (Safety Integrity Level SIL / Performance Level PL).