Siemens alarm 411502: Incorrect basic PLC program version
SINUMERIK PLC system alarm · Siemens 840D/810D powerline
What it means
The loaded PLC basic program does not match the version expected by the installed NCK software (Siemens attributes the detection to the FB15 interface check). Interface signatures between basic program, NCK and HMI must agree; any drift forces this alarm and prevents clean run-up. Load the basic program release that belongs to the NCK version on the machine.
Likely causes
- PLC basic program from a different SW step than the NCK image
- NCK upgraded (e.g. HMI/Operate update) without updating the toolbox basic program
- Restored archive pairing mismatched components
Triage note: Frequently seen together with 411501; both require bringing basic program, FB15 and NCK to one consistent version level.
Need the part urgently?
Send us alarm 411502 with your machine details — typical RFQ turnaround is 24–48h.