Siemens SINAMICS G120XA - CU: System Limit Exceeded; Buffer Memory: 70% Fill Level Reached or Exceeded; Buffer Memory: 100 % Fill Level Reached

Cause: It is not possible to write into a write-protected file (PSxxxxxx.acx). The write request was interrupted.
Alarm value (r2124, interpret decimal):
Drive object number.
Remedy: Check whether the "write protected" attribute has been set for the files in the non-volatile memory under .../USER/
SINAMICS/DATA/... When required, remove write protection and save again (e.g. set p0971 to 1).
F01054 CU: System limit exceeded
Reaction: OFF2
Acknowledge: IMMEDIATELY
Cause: At least one system overload has been identified.
Fault value (r0949, interpret decimal):
1: Computing time load too high (r9976[1]).
5: Peak load too high (r9976[5]).
Note:
As long as this fault is present, it is not possible to save the parameters (p0971).
See also: r9976 (System utilization)
Remedy: For fault value = 1, 5:
- reduce the computing time load of the drive unit (r9976[1] and r9976[5]) to under 100 %.
- check the sampling times and adjust if necessary (p0115, p0799, p4099).
- deactivate function modules.
- deactivate drive objects.
- remove drive objects from the target topology.
- note the DRIVE-CLiQ topology rules and if required, change the DRIVE-CLiQ topology.
When using the Drive Control Chart (DCC) or free function blocks (FBLOCKS), the following applies:
- the computing time load of the individual run-time groups on a drive object can be read out in r21005 (DCC) or r20005
(FBLOCKS).
- if necessary, the assignment of the run-time group (p21000, p20000) can be changed in order to increase the sampling
time (r21001, r20001).
- if necessary, reduce the number of cyclically calculated blocks (DCC) and/or function blocks (FBLOCKS).
A01066 Buffer memory: 70% fill level reached or exceeded
Reaction: NONE
Acknowledge: NONE
Cause: The non-volatile buffer memory for parameter changes is filled to at least 70%.
This can also occur if the buffer memory is active (p0014 = 1) and parameters are continually changed via a fieldbus
system.
Remedy: If required, deactivate and clear the buffer memory (p0014 = 0).
If required, clear the buffer memory (p0014 = 2).
In the following cases, the entries in the buffer memory are transferred into the ROM and then the buffer memory is cleared:
- p0971 = 1
- switch-off/switch-on Control Unit
See also: p0014 (Buffer memory mode)
A01067 Buffer memory: 100 % fill level reached
Reaction: NONE
Acknowledge: NONE
Cause: The non-volatile buffer memory for parameter changes is filled to 100%.
All additional parameter changes will no longer be taken into account in the non-volatile buffer memory. However,
parameter changes can still be made in the volatile memory (RAM).
This can also occur if the buffer memory is active (p0014 = 1) and parameters are continually changed via a fieldbus
system.
Warnings, faults and system messages
9.6 List of fault codes and alarm codes
SINAMICS G120XA converter
Operating Instructions, 03/2019, FW V1.0, A5E44751205B AB 763