What it means
F35950 reports an internal software error inside the Terminal Module (TM). The drive stores a fault value in r0949, which is to be read as a decimal number; it identifies the fault source, and the manuals state plainly that this information is only for internal Siemens troubleshooting — no decoding of the value is published.
Why it appears
- The Terminal Module has run into an internal software error. The manuals that describe F35950 name this single cause and give no further detail behind it.
What to check
- Read the fault value in r0949 (decimal) and keep a note of it — it identifies the fault source and is the information Technical Support works with.
- If necessary, upgrade the firmware in the Terminal Module to a later version.
- If the fault persists, contact Technical Support.
Reading the message value
- The drive enters the fault value into r0949; interpret it as a decimal number.
- The value carries information about the fault source and is intended only for internal Siemens troubleshooting.
- The manuals print no breakdown of individual values, so no decoding of the number is available.
Parameters the manual names
- r0949 — fault value of this message; read it as a decimal number, it names the fault source and is meant for internal Siemens troubleshooting.
Acknowledging and restarting
The drive reacts by switching off pulses, so the motor coasts down. A simple acknowledge is not enough for this fault: it is only cleared by switching the drive's power supply off and on again. Once the supply has been cycled, the drive can be restarted as usual.
What differs between the drive families
Straight from the manuals' own fields — F35950 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | OFF2 (NONE) | POWER ON | Hardware/software error (1) | Terminal Module (TM) | SINAMICS S120, S150 List Manual · p. 3248 |
| G130, G150 | OFF2 (NONE) | POWER ON | Hardware/software error (1) | Terminal Module (TM) | SINAMICS G130, G150 List Manual · p. 1910 |
| G120 | OFF2 (NONE) | POWER ON | Hardware/software error (1) | — | SINAMICS G120 · p. 933 |
| G120XA | OFF2 (NONE) | POWER ON | — | — | SINAMICS G120XA PN converter · p. 1167 |
The drives this code lives on
F35950 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 F35950 mean on a SINAMICS drive?
It means the Terminal Module has detected an internal software error. The drive switches off pulses and stores a fault value in r0949 that identifies the fault source.
How do I clear and reset F35950?
A normal acknowledge is not sufficient — the power supply must be switched off and on again. If the fault comes back, upgrade the Terminal Module firmware to a later version and then contact Technical Support.
What is the fault value of F35950 in r0949?
A decimal number that identifies the fault source. It is only intended for internal Siemens troubleshooting, and no decoding of the value is published.
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 F35xxx group · SINAMICS manuals · Siemens manuals