The undulator control system is based on off-the-shelf components commonly used for industrial automation. The use of the high performance real-time fieldbus EtherCAT makes it possible to implement both the numerical control (NC) and the programmable logic controller (PLC) as software tasks on a standard industrial PC instead of using expensive dedicated hardware. The gap drive consists of two independent servo axes for each magnet girder to allow for maximum flexibility, needed e.g. for tapering or beam height adjustment.
Each axis is equipped with a multi-turn absolute rotary encoder to ensure an operational reliability even after electrical power loss. The four axes are synchronized electronically via the NC. The PLC monitors all mechanically relevant operating conditions like the tilt of girders or limit switches. It also controls peripheral components such as power supplies for corrector coils and provides interfaces for communication with the global and beam line control systems.