Commissioning
9.4 Operating and system states
S7-1500R/H redundant system
System Manual, 10/2018, A5E41814787-AA
215
Table 9- 11 Sequence of events: SYNCUP aborts
No. in
dia-
gram
Primary CPU
System state
Backup CPU
Initial situation: The S7-1500R/H redundant system is in the SYNCUP system state. An error occurs in the backup CPU.
①
The CPU does not switch from the RUN-
Syncup operating state to RUN-Redundant,
but instead returns to RUN and continues to
execute the user program.
SYNCUP → RUN
-Solo
If SYNCUP aborts, the backup
CPU may restart and then
switch to the STOP operating
state. The backup CPU is
ready for a new SYNCUP.
Procedure for error correction
1.
Eliminate the error.
2.
Switch the backup CPU from STOP to RUN.
The backup CPU switches from STOP to the SYNCUP operating state. Synchronization
restarts.
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 9- 12 SYNCUP abort: Causes and solutions
Cause of SYNCUP abort
Solution
Too little memory on the SIMATIC memory card of the
backup CPU.
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/59193
System overload. The user program load is too high, and
the backup CPU is therefore not catching up with program
execution on the primary CPU.
Use the "RT_INFO" instruction to generate statistics on the
runtime of OBs, communication or the user program. You
can establish the system load using asynchronous instruc-
tions.
You can shorten the backup CPU delay compared to the
primary CPU by:
•
Addressing the CPU overload by reducing the post-
processing 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
http://support.automation.siemens.com/WW/view/en/59
) function manual.
•
Do not set too low a minimum cycle time for cyclic OBs
or increase the minimum cycle time. This reduces the
frequency at which the cyclic OBs are called.
Summary of Contents for Simatic S7-1500H
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