Siemens alarm 300506: Axis %1 drive %2 NC sign-of-life failure
SINUMERIK 840D/810D powerline drive alarm (SIMODRIVE 611D) · SIMODRIVE 611D/611U
What it means
In every position-control cycle the NC must refresh the sign-of-life handshake to each enabled drive; here an update was missed, so the drive dropped its pulses. On multi-drive n-axis configurations the message often appears on all axes although only one axis genuinely caused it.
Likely causes
- consequential failure: another axis' alarm stopped NC updates (fix that axis first)
- drive bus communication disturbance (cable, screening, termination)
- hardware defect in the addressed drive module
- NC hardware fault (rare)
- MD 10082 $MN_CTRLOUT_LEAD_TIME set too large, or wrong STS config MD 1003
Triage note: Check whether this alarm is preceded by another drive alarm in the log - treating it standalone wastes time.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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6FX2003-…
cable · Common cause
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6SN1118-…
control-board · Check if others ruled out
Need the part urgently?
Send us alarm 300506 with your machine details — typical RFQ turnaround is 24–48h.