: Ensure all commissioning parameters are set.
| | Recommended Action | Result | | :--- | :--- | :--- | | New User / Standard Commissioning | Perform the motor identification routine (Start command). Then set P0971 = 1 to save. | Drive is fully optimized, high torque accuracy, alarm clears automatically. | | Expert / Emergency Bypass | Set P1900 = 0 to deactivate the routine. CAUTION: Only use if you are sure the motor data is already correct. | Alarm clears immediately, but motor performance may be sub-optimal. |
in Siemens drive systems (such as SINAMICS S120 or G120) refers to a
The drive is in a commissioning mode where it is measuring the motor's electrical characteristics (resistance, inductance, etc.) to optimize performance. Why it shows up: siemens fault 0a7991 best
: The drive will inject current into the motor windings for roughly 10 to 15 seconds. The motor may hum but will not rotate.
Does the fault happen or during a specific machine movement ? Are you using PROFINET or PROFIBUS ?
Siemens fault code 0A7991 is a critical diagnostic alert typically associated with industrial automation systems, specifically within the SINAMICS drive family or SIMATIC controllers. When this fault appears, it usually indicates a communication breakdown or a specific hardware synchronization error that halts production. : Ensure all commissioning parameters are set
: The motor may emit a whistling sound for several seconds while it identifies resistance and inductance.
: Motor nameplate credentials (voltage, current, power, efficiency, frequency, speed).
: Ensure no active safety or communication faults exist on the drive. | Drive is fully optimized, high torque accuracy,
This alarm triggers when the drive is in a commissioning state and requires an Motor ID run
💡 If your PLC cycle time is too high, consider moving non-critical logic to a different cyclic interrupt (OB) to prioritize the motion control communication. When to Contact Siemens Support
The Siemens drive alarm indicates that Motor Data Identification (Motor ID) is actively running or scheduled to execute at the next power-on command . It is not a hardware failure or a broken component; rather, it is a built-in status warning appearing on the Basic Operator Panel (BOP-2), Intelligent Operator Panel (IOP), or within Siemens TIA Portal during the commissioning or optimization of Siemens SINAMICS drives (such as the G120, G120C, G130, S120, and V70 series).