Siemens alarm 411501: Incorrect version of FB 15, > general reset, do not transmit FB 15 from project
SINUMERIK PLC system alarm · Siemens 840D/810D powerline
What it means
Function block FB15 (the SPL/safety-linked block of the basic program) does not belong to the PLC basic program version currently in the CPU - typically because an offline project still contained an older FB15 that was downloaded over the correct one. Siemens prescribes a general PLC reset and reloading the matching basic program, explicitly NOT transmitting FB15 from the user project. Until fixed, safety-related data cross-checks cannot be trusted.
Likely causes
- User STEP 7 project contains stale FB15 from a different toolbox release
- Mixed-version download: basic program updated but FB15 taken from the old project
- Backup/restore across different software steps
Triage note: Companion alarm 411502 fires when the basic program itself mismatches the NCK/HMI version expectation; 411503 flags wrong NCU type in the hardware configuration.
Need the part urgently?
Send us alarm 411501 with your machine details — typical RFQ turnaround is 24–48h.