Step 5: Transition To Redundant System Mode - Siemens SIMATIC PCS 7 System Manual

System modifications during redundant operation
10.5 Editing CPU parameters
Reaction of the I/O
Type of I/O
I/O modules
1) 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).
Where the values for the monitoring times in the CPUs differ, the higher values always apply.
10.5.6

Step 5: Transition to redundant system mode

Starting situation
The fault-tolerant system operates with the modified CPU parameters 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".
Result
The reserve CPU links up and is updated. The fault-tolerant system is operating in redundant
system mode.
Note
Any set up access right is not canceled until you stop the SIMATIC Manager. You should
reset the access right once again to prevent unauthorized access. You reset the access right
in the SIMATIC Manager with the menu command PLC > Access Rights > Cancel.
166
One-sided I/O of previous
master CPU
are no longer addressed by the
CPU.
Output modules output the
configured substitute or holding
values.
One-sided I/O of new master
CPU
are given new parameter set-
tings and updated by the
1)
CPU.
CPU 410-5H Process Automation/CPU 410 SMART
Switched I/O
continue operation without
interruption.
System Manual, 09/2014, A5E32631667-AB