The Ferrocontrol DARC S04‑00‑2Q is a digital axis controller used in Elumatec machines; it receives a 600 VDC intermediate circuit from the DARC supply module and modulates it into the three‑phase voltage required to drive the synchronous motor, with resolver feedback for position. Common failure modes for this class of servo modules include power‑supply degradation (voltage ripple or over‑temperature), I/O interface faults (open/short on encoder or resolver signals), overheating of the internal MOSFET array, and firmware corruption that can trigger error codes such as “I/O fault” or “overcurrent”. First‑check diagnostics: verify the 600 VDC supply rail is within spec and free of ripple; inspect all I/O connectors for corrosion or loose contacts, especially resolver leads; review the controller’s diagnostic display or log for recent fault codes.[oss-gpt-20b]