F01054 — CU: System limit exceeded

The Control Unit (CU) raises F01054 when at least one system overload has been identified. The fault value in r0949, read as a decimal number, tells which system limit was exceeded: 1 means the computing time load is too high (r9976[1]), 5 means the peak load is too high (r9976[5]). The manuals describe the code identically for every listed converter family, so there are no family-specific causes.

• At least one system overload has been identified by the Control Unit.
• Computing time load too high — signalled with fault value 1 (r9976[1]).
• Peak load too high — signalled with fault value 5 (r9976[5]).

1. Read the fault value in r0949 (decimal) to see whether the computing time load (1) or the peak load (5) is too high.
2. Reduce the computing time load of the drive unit (r9976[1] and r9976[5]) to under 100 %.
3. Check the sampling times and adjust them if necessary (p0115, p0799, p4099).
4. Deactivate function modules.
5. Deactivate drive objects.
6. Remove drive objects from the target topology.
7. Note the DRIVE-CLiQ topology rules and, if required, change the DRIVE-CLiQ topology.
8. When the Drive Control Chart (DCC) or free function blocks (FBLOCKS) are used, read out the computing time load of the individual runtime groups on a drive object in r21005 (DCC) or r20005 (FBLOCKS).
9. If necessary, change the assignment of the runtime group (p21000, p20000) in order to increase the sampling time (r21001, r20001).
10. If necessary, reduce the number of cyclically calculated blocks (DCC) and/or function blocks (FBLOCKS).

• The drive outputs the fault value as the message value; it is held in r0949 and must be interpreted as a decimal number.
• 1: Computing time load too high (r9976[1]).
• 5: Peak load too high (r9976[5]).

• r0949 (fault value) — read it as a decimal number to see whether fault value 1 or 5 tripped F01054.
• r9976 (system utilization) — index 1 shows the computing time load, index 5 the peak load; bring both under 100 %.
• p0971 (save drive object parameters) — saving is not possible as long as F01054 is present.
• p0977 (save all parameters) — named alongside p0971 in the note of some manuals; likewise blocked while the fault is present.
• p0115 (sampling time for supplementary functions) — check and adjust if necessary.
• p0799 (CU inputs/outputs sampling time) — check and adjust if necessary.
• p4099 (inputs/outputs sampling time) — check and adjust if necessary.
• r20001 (run-time group sampling time) — can be increased via the runtime group assignment to lower the DCC/FBLOCKS computing load.

The drive coasts down (OFF2). Remedy the overload first: as long as the fault is present, it is not possible to save the parameters (p0971; some manuals also name p0977 here). Then acknowledge the fault immediately — after that the drive can be restarted.