Siemens alarm 810001: Error OB event, error analysis via STEP7 required
SINUMERIK PLC system alarm · Siemens 840D sl
What it means
This is one of the reduced PLC system error messages (range 810001-810009) that the control displays when the SIMATIC-side diagnostic buffer records an event; here an error organisation block was called. The HMI text is intentionally terse - the actual diagnosis (OB number, stack, station) lives in the PLC diagnostic buffer readable with STEP 7. Use STEP 7 online diagnostics to pinpoint the fault location.
Likely causes
- Programming error triggering a synchronous/diagnostic OB
- System-level event in the S7 CPU forwarded to the HMI
- Hardware fault raising a diagnostic interrupt OB
Triage note: Range marker for the documented standard 'system error messages from PLC' 810001-810009 (plus 810015 on sl); per Siemens these are analysed exclusively via the STEP 7 diagnostic buffer.
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