Abstract: The invention relates to a controller for a wind turbine with an operating software for operating the wind turbine, wherein the operating software is set up to regulate or control at least an electrical output of a wind turbine generator, a speed of a wind turbine rotor, an azimuth angle of a wind turbine nacelle, and a pitch angle of at least one rotor blade of the wind turbine rotor, wherein the operating software comprises a core module and at least one customer application. The customer application is set up to determine a parameter, in particular a control variable, in particular a target value, depending on at least one function of the customer application, and provide it for the core module.

Abstract: A method of providing an electronic key for an access, in particular a control access, to at least one wind turbine or at least one wind farm controller with an access control system, which includes receiving a request for an access to one or more wind turbines selected with the request and/or one or more wind farm controllers selected with the request from an input means or a data interface of the access control system, retrieving data of the one or each of the selected wind turbines and/or the one or each of the selected wind farm controllers by the access control system, and creating and issuing at least one electronic key for the one or each of the selected wind turbines and/or the one or each of the selected wind farm controllers when a criterion is met, wherein a decision as to whether the criterion is met is made depending on the retrieved data by the access control system. An access control system is also provided.