Siemens SIMATIC S7-1500 System Manual page 280

Commissioning
11.4 Operating and system states
Causes of error and troubleshooting
There are various possible causes of a SYNCUP system state abort. In the event of a SYNCUP
abort, evaluate the diagnostics buffer of the primary and the backup CPU.
Table 11-13 SYNCUP abort: Causes and solutions
Cause of SYNCUP abort
Too little memory on the SIMATIC memory card of the backup
CPU.
The name of files or directories on the SIMATIC memory card
of the backup CPU contains unsupported characters.
The number of hierarchy levels used in directories on the
SIMATIC memory card of the backup CPU is too large.
System overload. The user program load is too high, and the
backup CPU is therefore not catching up with program execu­
tion on the primary CPU.
The load on the redundancy connections between primary
and backup CPU is too high. As a result, the backup CPU is not
catching up with program execution on the primary CPU.
Maximum cycle time in the primary CPU exceeded
Primary CPU or backup CPU goes into STOP operating state.
PROFINET ring interrupted
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Solution
Delete data from the SIMATIC memory card or use a SIMATIC
memory card with greater memory capacity. You can find
more information in the function manual Structure and use of
the CPU memory
(https://support.industry.siemens.
com/cs/ww/en/view/59193101).
Make sure that file and/or directory names do not contain
umlauts (ö, ä, ü, Ö, Ä, Ü).
Make sure that the directory structure does not consist of
more than 6 hierarchy levels (e.g. (F:) SIMAT­
IC MC/1/2/3/4/5/6/file.txt).
Use the "RT_INFO" instruction to generate statistics on the
runtime of OBs, communication or the user program.
You can shorten the backup CPU delay compared to the
primary CPU by:
• Addressing the CPU overload by reducing the post-pro­
cessing of cyclic events (events from one source, for
example start events for a cyclic interrupt OB).
You can find more information in the Cycle and response
times
(https://support.industry.siemens.
com/cs/ww/en/view/59193558) function manual.
• Not setting too low a minimum cycle time for program
cycle OBs or increasing the minimum cycle time. This
reduces the frequency at which the program cycle OBs are
called.
Reduce the load on the redundancy connections between
primary and backup CPU by:
• Reducing the post-processing of cyclic events (see above)
• Avoiding instructions that increase the synchronization
load, for example direct access, time access (for example
RD_SYS_T, WR_SYS_T, RD_LOC_T)
• Reducing communication (HMI, PG/PG, Open User Com­
munication, etc.)
• Complying with the configuration rules
• Reduce the cycle time by setting a lower communication
load in the hardware configuration.
• Configure a sufficiently long maximum cycle time.
• If there is an OB 80 (time error OB) in the downloaded
user program, it is called by the operating system to toler­
ate the cycle time being exceeded (see section Start
events (Page 220)).
Switch the primary CPU or backup CPU into RUN operating
state.
Replace defective PROFINET cables or PROFINET devices in the
PROFINET ring.
System Manual, 11/2022, A5E41814787-AD
S7-1500R/H redundant system