Siemens Fault 0a7991 !!install!! -

This alarm frequently appears alongside , which indicates a communication timeout with a PLC.

The Siemens fault code (often searched as 0a7991 ) specifically indicates that Motor Data Identification is activated . This is not a critical equipment failure but rather a status alarm triggered during the commissioning or configuration phase of Siemens SINAMICS drives , such as the G120, G120C, and G150 series. Understanding Alarm A07991

If you do not wish to perform the identification (e.g., during bench testing without a motor), you can disable it via the Siemens Parameter List : siemens fault 0a7991

Apply a (start signal) to initiate the routine.

Removes the requirement for motor details for initial testing. This alarm frequently appears alongside , which indicates

: If testing the drive standalone, set p2030 = 0 (No protocol) and perform a "RAM to ROM" save. Technical Summary Table Default/Action Description p1900 Set to 0 Disables the motor identification routine. p0971 Set to 1

Set (Control mode: V/f standard) if advanced vector control isn't needed immediately. 3. Resolving Persistent Alarms (A07991 + A8526) Understanding Alarm A07991 If you do not wish

The most direct fix is to allow the drive to perform the check.