What it means
The manuals print this message as SI P1 (CU): Simulation of the safety inputs active
. F01661 is raised by the Control Unit (CU) when the simulation of its digital inputs (p0795) is active and the safety inputs are among the simulated ones — the manuals state plainly that it is not permissible to simulate safety inputs. The G120, G130, G150, S120 and S150 manuals describe this fault identically, so the same cause and remedy apply regardless of family.
Why it appears
- The simulation of the digital inputs of the Control Unit (p0795) is active.
- Safety inputs must not be simulated, so the drive does not accept this condition.
What to check
- Read the fault value in r0949 as a binary number: the displayed bits show which digital inputs must not be simulated.
- Deactivate the simulation of the digital inputs of the Control Unit for the safety inputs (p0795).
- Acknowledge the fault.
Reading the message value
- The message value is shown as
Fault cause: %1 bin
— %1 is the fault cause, written to r0949 and to be interpreted binary. - Each displayed bit indicates one digital input that must not be simulated; no further bit-by-bit decoding is printed for this fault.
Parameters the manual names
- p0795 — CU digital inputs simulation mode / CU DI simulation: this is where the digital-input simulation of the Control Unit is set; deactivate it for the safety inputs to clear F01661.
- r0949 — fault value: read the fault cause here, interpreted binary; the set bits show which digital inputs must not be simulated.
Acknowledging and restarting
Switch off the simulation for the safety inputs in p0795 first, then acknowledge the fault. While the fault is present the drive coasts down and must be acknowledged before it will start again.
What differs between the drive families
Straight from the manuals' own fields — F01661 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | OFF2 | IMMEDIATELY | General drive fault (19) | Control Unit (CU) | SINAMICS S120, S150 List Manual · p. 2646 |
| G130, G150 | OFF2 | IMMEDIATELY | General drive fault (19) | Control Unit (CU) | SINAMICS G130, G150 List Manual · p. 1445 |
| G120 | OFF2 | IMMEDIATELY | General drive fault (19) | — | SINAMICS G120 · p. 846 |
The drives this code lives on
F01661 is described for G120, G130, G150, S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does F01661 mean on a SINAMICS drive?
The Control Unit is simulating its digital inputs (p0795) and the simulation reaches the safety inputs, which must never be simulated. The fault value in r0949, read in binary, shows which inputs are affected.
How do I clear F01661?
Deactivate the simulation of the Control Unit digital inputs for the safety inputs in p0795 and then acknowledge the fault. The drive starts again only after the fault has been acknowledged.
Can I leave the digital-input simulation on for commissioning?
Not for the safety inputs — the manuals state that simulating them is not permissible. Deactivate the simulation in p0795 for these inputs; the fault value shows in binary which inputs are meant.
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