Siemens alarm F31110: Encoder 1: Serial communications error
SINAMICS S120 encoder fault (Sensor Module / DRIVE-CLiQ encoder) · SINAMICS S120
What it means
The serial protocol transfer between an absolute encoder (e.g. EnDat) and its evaluation module failed. The binary fault value is a rich diagnostic map: alarm bit in the position telegram, wrong quiescent level, no encoder response within 50 ms, CRC mismatch, acknowledgement errors, timeouts on cyclic/register communication, parity/frame errors and more. Each bit maps to a specific remedy in the manual - from EMC measures to replacing encoder, cable or Sensor Module.
Likely causes
- EMC disturbance - missing/unconnected cable shield
- incorrect encoder type selected versus actual device
- defective encoder electronics
- Sensor Module serial interface failing
- parameterization mismatches (p0429, p0436, p0449)
Triage note: Interpret r0949 bit-wise; EnDat 2.2 details follow F31x35 semantics.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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6FX2001-… encoder cable
cable · Common cause
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6SL3362-0AG01-0AA0 SME25 / matching Sensor Module
sensor-module · Common cause
Need the part urgently?
Send us alarm F31110 with your machine details — typical RFQ turnaround is 24–48h.