What it means
F31851 means that the Control Unit has detected a DRIVE-CLiQ communication error on the path from the Sensor Module (encoder 1) involved: the DRIVE-CLiQ component did not set the sign-of-life to the Control Unit, so the sign-of-life bit in the receive telegram is missing. Depending on how the drive is configured, the same condition can also be issued as an alarm (A) or with no reaction (N) instead of a fault.
Why it appears
- A DRIVE-CLiQ communication error has occurred from the Sensor Module (encoder 1) involved to the Control Unit.
- The DRIVE-CLiQ component did not set the sign-of-life to the Control Unit.
- The only fault cause the manual decodes for this code is value 10: the sign-of-life bit in the receive telegram is not set.
What to check
- Read the message value — r0949 while the code is present as a fault, r2124 when it appears as an alarm; it identifies the DRIVE-CLiQ component that stopped setting the sign-of-life and the fault cause.
- Upgrade the firmware of the component involved.
- Carry out a POWER ON (switch-off/switch-on) for the component involved.
Reading the message value
- The drive enters the component number and the fault cause into the message value, which is stored in r0949 (fault) or r2124 (alarm):
The individual information is coded as follows in the message value (r0949/r2124): 0000yyxx hex: yy = component number, xx = error cause
- For this code the manual decodes fault cause
10 (= 0A hex)
as: the sign-of-life bit in the receive telegram is not set.
Parameters the manual names
- r0949 — fault value: read here which DRIVE-CLiQ component is involved and that the fault cause is 10 for this code.
- r2124 — alarm value: holds the same coded component number and fault cause when the sign-of-life condition is raised as an alarm.
Acknowledging and restarting
The remedies are upgrading the firmware of the component involved and a POWER ON (switch-off/switch-on) of that component. Once the Sensor Module is again setting the sign-of-life to the Control Unit, acknowledge the fault so the drive can be restarted. In the alarm and no-message variants the manual specifies neither a reaction nor an acknowledgement.
What differs between the drive families
Straight from the manuals' own fields — F31851 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | Infeed: NONE (OFF1, OFF2) Servo: ENCODER (IASC/DCBRK, NONE) Vector: ENCODER (IASC/DCBRK, NONE) Hla: ENCODER (NONE) | — | Internal (DRIVE-CLiQ) communication error (12) | Sensor Module Encoder 1 | SINAMICS S120, S150 List Manual · p. 3069 |
| G130, G150 | Vector: ENCODER (IASC/DCBRK, NONE) Infeed: NONE (OFF1, OFF2) | IMMEDIATELY | Internal (DRIVE-CLiQ) communication error (12) | Sensor Module Encoder 1 | SINAMICS G130, G150 List Manual · p. 1753 |
The drives this code lives on
F31851 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 F31851 mean on a SINAMICS drive?
The Control Unit is no longer receiving the sign-of-life from the Sensor Module of encoder 1 over DRIVE-CLiQ — the sign-of-life bit in the receive telegram is not set.
How do I clear F31851?
Upgrade the firmware of the component involved or carry out a POWER ON (switch-off/switch-on) for that component, then acknowledge the fault. The component number stored in r0949 tells you which DRIVE-CLiQ component is affected.
What is fault cause 10 in the message value for F31851?
It is the only cause the manual decodes for this code: the sign-of-life bit in the receive telegram is not set (10 = 0A hex). The full value is coded 0000yyxx hex, where yy is the component number and xx the fault cause.
Can F31851 also appear as an alarm?
Yes — depending on the drive configuration the same condition can be issued as an alarm (A) or with no reaction (N); for both variants the manual gives no reaction and no acknowledgement.
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