If the identification was activated by mistake or if you urgently need to bypass it (for example, in a production environment where you cannot run the motor for 10 seconds without causing a product crash), you can cancel it.
or "Timeout for internal data exchange"
: Once the measurement finishes, the drive will stop, and the alarm should automatically clear (Parameter will return to 2. Disable Motor ID for Testing (FAT/Bypass) If you are performing a Factory Acceptance Test (FAT) siemens fault 0a7991 best
– A mismatch between the Control Unit firmware and the power unit firmware, or corrupted flash memory.
By following these best practices and guidelines, users can minimize the risk of encountering the Siemens fault 0A7991 and ensure optimal device performance. If the identification was activated by mistake or
If the setup process was never fully finalized or saved from RAM to ROM, the drive will re-trigger the identification routine upon the next power-on sequence.
To minimize the risk of encountering the Siemens fault 0A7991, follow these best practices: By following these best practices and guidelines, users
The drive obtains these values by running a series of high-frequency test currents through the motor windings while it remains stationary (standstill measurement) or during low-speed rotation. Common Causes for A07991 Triggers
You have changed the motor configuration (P0300-P0311) and the drive requires a re-identification.
: Usually implies a communication bit (Bit 10) from the PLC is at "0" level, preventing the drive from responding.
During initial setup using software tools like Siemens Startdrive or the Basic Operator Panel (BOP-2), the commissioning wizard automatically activates motor identification to optimize torque performance and thermal protection.