What it means
F01120 — Terminal initialization has failed. An internal software error occurred while the drive was initializing its terminal functions. The manuals describe this one single cause, and depending on the drive's configuration the same condition can also be reported as an alarm (A) instead of a fault.
Why it appears
- The terminal functions could not be initialized because of an internal software error — the manuals list no other cause.
What to check
- Carry out a POWER ON (switch-off/switch-on) for all components.
- Upgrade the firmware to a later version.
- If the fault returns, contact Technical Support.
- As the last step, replace the Control Unit.
Reading the message value
- The manuals print the message value as a placeholder (%1) that the drive fills with the fault value from r0949.
- Interpret the value in r0949 hexadecimal — but the manual states it is
Only for internal Siemens troubleshooting
, so it contains nothing the technician can act on.
Parameters the manual names
- r0949 — fault value of this message; read it hexadecimal, though the manuals reserve the content for internal Siemens troubleshooting.
Acknowledging and restarting
Acknowledge the fault IMMEDIATELY. The manuals also name POWER ON (switch-off/switch-on) as the acknowledgement for this code, and the remedy list begins with exactly that step — switch the power off and back on for all components. If F01120 comes back after the POWER ON, continue with the firmware upgrade and the remaining remedy steps.
What differs between the drive families
Straight from the manuals' own fields — F01120 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| G130, G150 | OFF1 (OFF2) | IMMEDIATELY (POWER ON) | Hardware/software error (1) | None | SINAMICS G130, G150 List Manual · p. 1392 |
| S120, S150 | OFF1 (OFF2) | IMMEDIATELY (POWER ON) | Hardware/software error (1) | None | SINAMICS S120, S150 List Manual · p. 2579 |
| G120 | OFF1 (OFF2) | IMMEDIATELY (POWER ON) | Hardware/software error (1) | — | SINAMICS G120 · p. 831 |
| G120XA | OFF1 (OFF2) | IMMEDIATELY (POWER ON) | — | — | SINAMICS G120XA PN converter · p. 1109 |
The drives this code lives on
F01120 is described for G120, G120XA, G130, G150, S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does fault F01120 mean on a SINAMICS drive?
F01120 means terminal initialization has failed: an internal software error occurred while the drive was initializing its terminal functions. Depending on the configuration it can also be reported as an alarm (A).
How do I fix F01120?
Carry out a POWER ON (switch-off/switch-on) for all components first. If the fault returns, upgrade the firmware to a later version, contact Technical Support, and replace the Control Unit as the last step.
Is F01120 caused by wiring at the terminals?
The manuals do not point to wiring: their only cause is an internal software error while the terminal functions were being initialized. The checks therefore start with a POWER ON of all components, not with terminal measurements.
What is the fault value of F01120 in r0949?
The drive stores the fault value in r0949 and it is interpreted hexadecimal. The manual states the value is only for internal Siemens troubleshooting, so it gives the technician nothing to act on.
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