What it means
F01205 means a time slice overflow in the Control Unit (CU): insufficient computation time is available for the existing topology, so the configured drives together demand more processing time than the CU has available. The CU stores a fault value for this fault in r0949, to be interpreted hexadecimal; the manual does not decode this value because it is reserved for internal Siemens troubleshooting.
Why it appears
- Insufficient processing time is available for the existing topology — the CU cannot compute the configured drives with the computation time it has. The G120 and G120XA manuals word the same cause as insufficient computation time.
What to check
- Reduce the number of drives — fewer drives need less computation time in the CU.
- Increase the sampling times.
- These two measures are printed for G130, G150, S120 and S150. For G120 and G120XA the manual gives no own measures and says to contact Technical Support; the G115D and G120C manuals list the fault in a short table without measures.
Reading the message value
- The CU writes the fault value to r0949; interpret the value hexadecimal. The message value shown with the fault (%1) contains this fault value.
- The manual gives no decoding of the value; its only note is:
Only for internal Siemens troubleshooting.
Parameters the manual names
- r0949 — fault value: read out which value the CU stored for F01205 and interpret it hexadecimal; the content is only intended for internal Siemens troubleshooting.
Acknowledging and restarting
When F01205 trips, the drive coasts down (OFF2) and will not start again until the fault has been acknowledged. Acknowledgment is only via POWER ON: switch the drive's power supply off and then on again — a reset without a power cycle does not clear the fault. Once the cause has been remedied and the power cycle performed, the drive can be restarted.
What differs between the drive families
Straight from the manuals' own fields — F01205 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| G130, G150 | OFF2 | POWER ON | Hardware/software error (1) | Control Unit (CU) | SINAMICS G130, G150 List Manual · p. 1394 |
| S120, S150 | OFF2 | POWER ON | Hardware/software error (1) | Control Unit (CU) | SINAMICS S120, S150 List Manual · p. 2582 |
| G120 | OFF2 | POWER ON | Hardware/software error (1) | — | SINAMICS G120 · p. 832 |
| G120XA | OFF2 | POWER ON | — | — | SINAMICS G120XA PN converter · p. 1109 |
| G115D | — | — | — | — | SINAMICS G115D distributed drive · p. 392 |
| G120C | — | — | — | — | SINAMICS G120C Converters · p. 382 |
The drives this code lives on
F01205 is described for G115D, G120, G120C, G120XA, G130, G150, S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does SINAMICS fault F01205 mean?
The Control Unit (CU) reports a time slice overflow: it does not have enough computation time for the existing topology. The fault value is stored in r0949 and is only for internal Siemens troubleshooting.
How do I fix fault F01205?
Reduce the number of drives and increase the sampling times — these are the measures the list manuals print for G130, G150, S120 and S150. For G120 and G120XA the manual instead says to contact Technical Support.
Why does F01205 not clear with a simple reset?
The fault can only be acknowledged via POWER ON: the power supply must be switched off and on again before the drive will start.
Where can I read the fault value of F01205?
In r0949, to be interpreted hexadecimal. The manual does not decode the value because it is reserved for internal Siemens troubleshooting.
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 F01xxx group · SINAMICS manuals · Siemens manuals