What it means
The drive raises F31151 — titled Encoder 1: Encoder speed for initialization AB too high
— when the encoder speed is too high while the Sensor Module of Encoder 1 is being initialized. The initialization of the Sensor Module only tolerates a slow encoder, and the drive monitors the speed throughout this phase. Depending on how the drive is configured, the same condition can also be output as an alarm (A) or with no reaction (N) instead of as a fault.
Why it appears
- The encoder connected to Encoder 1 was turning too fast at the moment the Sensor Module carried out its initialization.
What to check
- Reduce the speed of the encoder accordingly during initialization, so that Encoder 1 stays slow enough while the Sensor Module initializes.
- If the encoder speed cannot be reduced sufficiently, deactivate the monitoring with p0437.29 (Sensor Module configuration extended).
Parameters the manual names
- p0437 (Sensor Module configuration extended) — setting p0437.29 switches off the monitoring that raises this fault; use it only if the encoder speed during initialization cannot be reduced.
Acknowledging and restarting
F31151 is acknowledged with pulse inhibit: the drive only accepts the acknowledgment while it outputs no pulses, so bring the drive into a pulse-inhibited state first and then acknowledge the fault. When the drive is configured to output the condition only as an alarm (A) or with no reaction (N), the manual specifies no acknowledgment for those variants.
What differs between the drive families
Straight from the manuals' own fields — F31151 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | Infeed: NONE Servo: ENCODER (IASC/DCBRK, NONE, OFF1, OFF2, OFF3, STOP2) Vector: ENCODER (IASC/DCBRK, NONE, OFF1, OFF2, OFF3, STOP2) Hla: ENCODER (NONE, OFF1, OFF2, OFF3, STOP2) | PULSE INHIBIT | Error in the parameterization / configuration / commissioning procedure (18) | Sensor Module Encoder 1 | SINAMICS S120, S150 List Manual · p. 3044 |
| G130, G150 | Vector: ENCODER (IASC/DCBRK, NONE, OFF1, OFF2, OFF3, STOP2) Infeed: NONE | PULSE INHIBIT | Error in the parameterization / configuration / commissioning procedure (18) | Sensor Module Encoder 1 | SINAMICS G130, G150 List Manual · p. 1730 |
The drives this code lives on
F31151 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 F31151 mean on a SINAMICS drive?
It means the encoder speed was too high while the Sensor Module of Encoder 1 was being initialized. The drive monitors the speed during this initialization phase.
How do I fix F31151?
Reduce the speed of the encoder accordingly during initialization. If the speed cannot be reduced, deactivate the monitoring with p0437.29 and acknowledge the fault with pulse inhibit.
Can the F31151 monitoring be switched off?
Yes — p0437.29 (Sensor Module configuration extended) deactivates it. The manual suggests this only if reducing the encoder speed during initialization is not sufficient.
Does F31151 always appear as a fault?
No — depending on the drive configuration, the same condition can also be issued as an alarm (A) or with no reaction (N). In those variants the manual specifies no acknowledgment.
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