What it means
F31801 means the Control Unit (CU) has lost the sign-of-life of Encoder 1: a DRIVE-CLiQ communication error has occurred from the Control Unit to the encoder involved, and the sign-of-life bit in the receive telegram is not set — the drive reports this as fault cause 10 (= 0A hex). The same condition can also be output as an alarm or with no reaction; the drive's configuration decides which form appears.
Why it appears
- A DRIVE-CLiQ communication error has occurred from the Control Unit to the encoder involved.
- The sign-of-life bit in the receive telegram is not set (fault cause 10, i.e. 0A hex).
What to check
- Check the electrical cabinet design and the cable routing for EMC compliance.
- Replace the component involved.
Reading the message value
- The drive codes the component number and the fault cause together into one value, readable in r0949 (fault value) or r2124 (alarm value).
- Coding: 0000yyxx hex — yy is the component number, xx is the error cause.
- For F31801 the fault cause is 10 (= 0A hex): the sign-of-life bit in the receive telegram is not set.
Parameters the manual names
- r0949 — fault value: read the coded component number and fault cause of this message here.
- r2124 — alarm value: when the sign-of-life condition is raised as an alarm, the same coded value is read here.
- p0491 — motor encoder fault response ENCODER: sets the drive's response to this encoder fault.
- p9916 — DRIVE-CLiQ data transfer error shutdown threshold slave: shutdown threshold for DRIVE-CLiQ data transfer errors, which the manual cross-references for this message.
Acknowledging and restarting
The message must be acknowledged immediately; after the cause has been remedied and the fault acknowledged, the drive can be restarted. Where the condition is configured to appear only as an alarm or without reaction, no acknowledgement is required.
What differs between the drive families
Straight from the manuals' own fields — F31801 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | Infeed: OFF2 (NONE) Servo: ENCODER (IASC/DCBRK, NONE) Vector: ENCODER (IASC/DCBRK, NONE) Hla: ENCODER (NONE) | IMMEDIATELY | Internal (DRIVE-CLiQ) communication error (12) | Control Unit (CU) | SINAMICS S120, S150 List Manual · p. 3061 |
| G130, G150 | Vector: ENCODER (IASC/DCBRK, NONE) Infeed: OFF2 (NONE) | IMMEDIATELY | Internal (DRIVE-CLiQ) communication error (12) | Control Unit (CU) | SINAMICS G130, G150 List Manual · p. 1746 |
The drives this code lives on
F31801 is described for G130, G150, S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does fault F31801 mean on a SINAMICS drive?
It reports that the sign-of-life bit from Encoder 1 is missing in the DRIVE-CLiQ receive telegram, i.e. a DRIVE-CLiQ communication error between the Control Unit and the encoder involved (fault cause 10 = 0A hex).
How do I fix F31801?
Check the electrical cabinet design and the cable routing for EMC compliance, and replace the component involved if the message persists. Afterwards acknowledge the fault immediately.
Where can I read the fault cause of F31801?
In the message value r0949, or r2124 when the message appears as an alarm. The value is coded 0000yyxx hex — yy is the component number and xx the error cause, here 10 (= 0A hex).
Can F31801 also appear as an alarm?
Yes. Depending on the drive's configuration the same condition can be output as an alarm or with no reaction, in which case no acknowledgement is required.
Codes next to this one
Source
Written from Siemens' own List Manuals and operating instructions; every number, designation and parameter on this page is checked against them before publication.
All SINAMICS codes: fault and alarm codes · the F31xxx group · SINAMICS manuals · Siemens manuals