The error occurs when the HMI’s handshake with the NCK fails. Primary causes:
The CCU unit has physical switches that determine the OPI address. sinumerik 810d waiting for nck connection
If the screen stubbornly remains on "Waiting for NCK Connection," you may need to force a reset. On the CCU unit (usually integrated into the drive module), there is a reset button or a toggle switch (often labeled S1 or S3 depending on the revision). The error occurs when the HMI’s handshake with