Siemens alarm A31840: Encoder 1 DRIVE-CLiQ: error below the signaling threshold
SINAMICS S120 drive warning · SINAMICS S120
What it means
The DRIVE-CLiQ link to this encoder shows communication errors that individually stay below the shutdown threshold configured via p9916 - CRC errors, length/type/address mismatches, SYNC issues, sign-of-life gaps, buffer errors and timeouts. Treat it as a leading indicator: the same root causes produce hard transfer faults once degradation crosses the threshold.
Likely causes
- marginal DRIVE-CLiQ cable or connector contacts
- EMC coupling from parallel power routing
- beginning failure of the encoder's DCL transceiver
- excessively long/branched topology segment
Triage note: Check cabinet EMC layout and DRIVE-CLiQ wiring before it escalates to F31820/F31835-class faults.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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6FX2003-… DRIVE-CLiQ cable
cable · Common cause
Need the part urgently?
Send us alarm A31840 with your machine details — typical RFQ turnaround is 24–48h.