A02020 alarm in siemens 6RA80 DC Drive indicate that the Parameter cannot be changed. This means this parameter setting cannot be changed when the function generator is active (p4800 = 1).

1. See also: p4810, p4812, p4813, p4820, p4821, p4822, p4823, p4824, p4825, p4826, p4827, p4828, p4829
2. Stop the function generator before parameterizing (p4800 = 0).
3. If required, start the function generator (p4800 = 1).