What it means
F31875 is raised when the DRIVE-CLiQ communication from the DRIVE-CLiQ component involved to the Control Unit signals that the supply voltage has failed. The fault cause reported by the component is 9 (= 09 hex): the power supply voltage for the components has failed. Depending on how the drive is configured, the same condition can also be issued as an alarm or with no reaction instead of a fault.
Why it appears
- The supply voltage for the DRIVE-CLiQ component on the Encoder 1 input has failed, and the component reports this to the Control Unit over DRIVE-CLiQ communication.
- The fault cause is always 9 (= 09 hex): the power supply voltage for the components has failed.
What to check
- Carry out a POWER ON (switch-off/switch-on).
- Check the power supply voltage wiring for the DRIVE-CLiQ component — for example an interrupted cable or poor contacts.
- Check the dimensioning of the power supply for the DRIVE-CLiQ component.
Reading the message value
- The message value combines two items of information: the component number and the fault cause.
- Both are coded in the message value (r0949/r2124) as 0000yyxx hex: yy = component number, xx = error cause.
- For this code the error cause is 9 (= 09 hex), the failed power supply voltage for the components.
Parameters the manual names
- r0949 — read the coded fault value here: in the 0000yyxx hex format it tells you which component reported the failed supply voltage and the fault cause.
- r2124 — alarm value; when the condition is signalled as an alarm, the same coded component number and fault cause are found here.
Acknowledging and restarting
The fault must be acknowledged immediately before the drive will run again. The remedy itself — a POWER ON (switch-off/switch-on) — is also the acknowledgment step: power the drive down, remedy the supply voltage problem, and switch back on. If the drive is configured to signal this condition only as an alarm or with no reaction, no acknowledgment is required.
What differs between the drive families
Straight from the manuals' own fields — F31875 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | Infeed: OFF2 Servo: ENCODER (IASC/DCBRK, NONE) Vector: ENCODER (IASC/DCBRK, NONE) Hla: ENCODER (NONE) | IMMEDIATELY | Supply voltage fault (undervoltage) (3) | Sensor Module Encoder 1 | SINAMICS S120, S150 List Manual · p. 3071 |
| G130, G150 | Vector: ENCODER (IASC/DCBRK, NONE) Infeed: OFF2 | IMMEDIATELY | Supply voltage fault (undervoltage) (3) | Sensor Module Encoder 1 | SINAMICS G130, G150 List Manual · p. 1755 |
The drives this code lives on
F31875 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 F31875 (Encoder 1: power supply voltage failed) mean?
The DRIVE-CLiQ component on the Encoder 1 input signals to the Control Unit over DRIVE-CLiQ communication that its supply voltage has failed. The fault cause reported is 9 (= 09 hex).
How do I clear F31875 on a SINAMICS drive?
Carry out a POWER ON (switch-off/switch-on), then check the power supply voltage wiring of the DRIVE-CLiQ component for interrupted cables or contact problems, and check the dimensioning of its power supply. The fault must be acknowledged immediately.
Where can I read the fault value of F31875?
In r0949 (fault value) or r2124 (alarm value). It is coded 0000yyxx hex, where yy is the component number and xx the error cause — here 09 hex for the failed supply voltage.
Can F31875 also appear as an alarm?
Yes. Depending on the drive configuration, the same condition can also be issued as an alarm or with no reaction, and in those cases no acknowledgment 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