Abstract: A control system and a method arranged for redundant supply of power to active magnetic bearings adapted for support of a shaft or rotor in a rotating machine. The control system comprises at least two control modules which are supplied external power. The control modules are connectable to a base module comprising a first set of power and sensor signal pathways which can be switched in to provide contact between a first control module and the active magnetic bearings, and a second set of power and sensor signal pathways which can be switched in to provide contact between a second control module and the active magnetic bearings. Each control module comprises a switching mechanism which is controllable for connecting the control modules one at a time to the active magnetic bearings via the first set or via the second set of power and sensor signal pathways.