Step 7, Step Vi: Transition To The Redundant System Mode - Siemens SIMATIC S7-400H Manual

10.5.6

STEP 7, Step VI: Transition to the Redundant System Mode

Initial situation
The fault-tolerant system works with the new (restricted) hardware configuration in
Solo mode.
Procedure
1. In SIMATIC Manager select a CPU of the fault-tolerant system and select the
menu command PLC > Operating Mode.
2. In the Operating Mode dialog box select the standby CPU and click the
Restart (warm restart) button.
Result
Standby CPU links up again and is updated. The fault-tolerant system is working in
the Redundant system mode.
Behavior of the I/O
Type of I/O One-way I/O of standby
I/O modules to be Are no longer addressed by the CPU.
1)
removed
I/O modules that Are re-parameterized
and updated by the CPU.
continue to be
present
DP stations to be as for I/O modules to be removed (see above)
removed:
1) no longer contained in the hardware configuration, but still plugged in
2) Central modules are first reset in addition. Output modules briefly output 0 during this time (instead of the
substitute or holding values configured).
Behavior if monitoring times are exceeded
If one of the monitored times exceeds the maximum value configured the update is
interrupted. The fault-tolerant system remains in Solo mode with the previous
master CPU and in certain conditions attempts to perform the link-up and update
later. For more details refer to Section 5.3.
S7-400H Programmable Controller Fault-Tolerant Systems
A5E00068197-04
Modifications to the System while in Operation
One-way I/O of master
CPU
2)
Continue to work without interruption.
Switched I/O
CPU
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