Step 6: Transition To Redundant System State - Siemens SIMATIC PCS 7 System Manual

Reaction of the I/O
Type of I/O
I/O modules to be
removed
I/O modules still
present
DP stations to be
removed
1) No longer included in the hardware configuration, but still plugged in
2) Central modules are first reset. Output modules briefly output 0 during this time (instead of the
configured substitute or hold values).
Reaction to monitoring timeout
The update is canceled and no change of master takes place if one of the monitored times
exceeds the configured maximum. The fault-tolerant system remains in single mode with the
previous master CPU and, assuming certain conditions are met, attempts the master
changeover later. For additional information, refer to section Time monitoring (Page 117).
10.4.6

Step 6: Transition to redundant system state

Starting situation
The fault-tolerant system is operating with the new hardware configuration in single mode.
Procedure
1. In SIMATIC Manager, select a CPU of the fault-tolerant system, then select "PLC >
Operating Mode" from the menu.
2. From the "Operating Mode" dialog box, select the reserve CPU, then click "Warm
Restart".
CPU 410-5H Process Automation/CPU 410 SMART
System Manual, 09/2014, A5E32631667-AB
One-sided I/O of previ-
ous master CPU
are no longer addressed by the CPU.
1)
Driver blocks are no longer present.
are no longer addressed
by the CPU.
Output modules output
the configured substitute
or holding values.
as for I/O modules to be removed (see above)
System modifications during redundant operation
10.4 Removal of components
One-sided I/O of new
master CPU
are given new parameter
settings and updated by
2)
the CPU.
Switched I/O
continue operation with-
out interruption.
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