Loose cables (especially Profibus or MPI connections), faulty CCU modules, or seated "child cards" that have vibrated loose can disrupt the connection.
If the battery failed, your machine is "forgetting" who it is. sinumerik 810d waiting for nck connection
After 20+ years, capacitors dry out and chips fail. Power surges or improper shutdowns can corrupt the
Power surges or improper shutdowns can corrupt the NCK or PLC data, preventing the control from reaching a "Ready" state. It would move—but dangerously, blindly
| Category | Specific Cause | |----------|----------------| | | 24VDC dips or noise; missing 24V to NCU (NC unit) or MMC | | Bus/Cable | Damaged, loose, or incorrect serial/ethernet cable (RS232, TTY, or proprietary) | | Hardware | NCU (NCK) not booting (LEDs: green/red status), defective MMC/PCU | | Parameter | Incorrect machine data (MD10000, MD10012) for HMI communication | | Firmware/Software | Version mismatch between NCK system software and HMI software | | Boot sequence | NCK boot slower than HMI → HMI times out waiting |
That last line hit like a punch. Defaults meant the machine had zero knowledge of its own travel limits, acceleration curves, or backlash compensation. It would move—but dangerously, blindly.
She looked at Danforth. "The battery died. The NCK's BIOS settings and bootloader prefix are corrupted. It's not 'waiting' for a connection—it's waiting for a ghost. It can't find its own identity."