Siemens alarm 300505: Axis %1 drive %2 measuring circuit error of absolute track, code %3
SINUMERIK 840D/810D powerline drive alarm (SIMODRIVE 611D) · SIMODRIVE 611D/611U
What it means
Fault on absolute encoder track (C/D track wire-break for ERN1387; encoder hardware/EnDat interface monitoring for EQN1325). Fine-diagnostics bits include lighting failed, amplitude too small, undervoltage, CRC error, battery change necessary, encoder defective (bit 15).
Likely causes
- encoder LED/lighting failed or low signal amplitude (internal encoder defect)
- absolute-value battery exhausted (bit 6)
- wrong/damaged encoder cable or loose contact
- control board without/with defective EnDat interface
Triage note: Evaluate MD1023 $MD_ENC_ABS_DIAGNOSIS_MOTOR bit pattern to decide encoder vs cable vs control-board replacement; bit 15 = encoder defective.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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ERN1387 / EQN1325 (per MD1023 diagnosis bits)
motor encoder · Primary suspect
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6FX5002-2E…
encoder signal cable · Common cause
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6SN1118-…
SIMODRIVE 611D control board (EnDat interface) · Check if others ruled out
Need the part urgently?
Send us alarm 300505 with your machine details — typical RFQ turnaround is 24–48h.