Siemens alarm 428630: Failure of the PROFINET IO system
SINUMERIK PLC system alarm · Siemens 840D/810D powerline
What it means
The complete PROFINET IO system went down - OB82/OB86 reported the loss of the IO controller's device network rather than a single station. Every distributed device on that Ethernet subnet drops out simultaneously, which usually trips several machine functions at once. Check the PROFINET cabling/switch infrastructure feeding the IO devices and restore the link.
Likely causes
- Industrial Ethernet switch failure or power loss
- Trunk cable to the device group damaged/disconnected
- IO controller port fault on the NCU
- Network reconfiguration/IP conflict taking devices offline
Triage note: Per-device companions: 428631 failure of a PROFINET device, 428632-428634 restoration messages (with fault, parameterization error, preset/actual discrepancy).
Need the part urgently?
Send us alarm 428630 with your machine details — typical RFQ turnaround is 24–48h.