A control system for a wind turbine is provided. The control system includes a local terminal for locally generating wind turbine control commands, a control arrangement for generating control signals for the wind turbine on the basis of wind turbine control commands, and a switching arrangement for switching between a remote mode of operation over a main communication network, and a local mode of operation over a local communication network between the local terminal and the control arrangement such that a message passed between the local terminal and the control arrangement does not travel beyond the local communication network in the wind turbine. A method of locally controlling a wind turbine, and a wind park including a number of wind turbines, wherein each wind turbine comprises such a control system are also provided.