1021: Parameter cannot be written: Function block active

Info:
Data type:

Description:
Response error while writing a parameter, which does not allow a change in the value when the corresponding function block is active.

Reaction:
The parameter value is not accepted.

Cause/Remedy:
The function block does not support an 'online' change of this parameter.
The function block is active in a certain operating state, which does not allow an 'online' change of this parameter (e.g. MPGEN in a compensation movement).
The parameter was written too late, after activation of the function block or operating state.
The function block was not deactivated before writing the parameter or a status request is missing.