Siemens alarm 300200: Drive bus hardware fault
SINUMERIK 840D/810D powerline drive alarm (SIMODRIVE 611D) · SIMODRIVE 611D/611U
What it means
Hardware-level fault on the 611D drive bus between NCU and drive modules.
Likely causes
- drive bus ribbon/cable open or intermittent
- missing termination at bus ends
- damaged drive-bus transceiver in an individual drive module
- NCU drive-bus interface failure
Triage note: Isolate systematically: reseat bus connectors and terminators first; substitute cables before replacing electronics.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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6FX2003-…
611D drive bus cable set · Primary suspect
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6SN1123-… / 6SN1118-…
power module incl. fitted control board (transceiver fault) · Common cause
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NCU 57x.x (6FC5373-…)
NCU box (last resort after cables/modules ruled out) · Check if others ruled out
Need the part urgently?
Send us alarm 300200 with your machine details — typical RFQ turnaround is 24–48h.