Enercon develops and produces gearless wind power turbines that are a benchmark for the market in terms of power, reliability and lifespan. Therefore, research and development at Enercon determines the level of innovation. Enercon has chosen Moeller's XC100-FC modular programmable logic controller (PLC) with a fibre-optic CANopen interface for controlling and monitoring its aviation beacon system. This article describes first the controls needed in the wind turbines and then how the modular PLC from Moeller is integrated into such systems.