Step 7, Step 6: Switch To Cpu With Modified Configuration - Siemens SIMATIC S7-400H System Manual

14.5.6

STEP 7, step 6: Switch to CPU with modified configuration

Starting situation
The modified hardware configuration is downloaded to the standby CPU.
Procedure
1. In SIMATIC Manager, select a CPU of the fault-tolerant system, then choose "PLC >
2. In the "Operating Mode" dialog box, click the "Switch to..." button.
3. In the "Switch" dialog box, select the "with altered configuration" option and click the
4. Acknowledge the prompt for confirmation with "OK".
Result
The standby CPU links up, is updated and becomes the master. The previous master CPU
switches to STOP mode, the fault-tolerant system operates with the new hardware
configuration in single mode.
Reaction of the I/O
Type of I/O
Added I/O modules
I/O modules still
present
Added DP stations
Central modules are first reset. Output modules briefly output 0 during this time (instead of the configured substitute or
1)
hold values).
Reaction to monitoring timeout
The update is aborted 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 further information, refer to section Time monitoring (Page 106).
S7-400H
System Manual, 09/2007, A5E00267695-03
Operating Mode" from the menu.
"Switch" button.
One-sided I/O of previous
master CPU
are not addressed by the CPU. are given new parameter settings and updated by the CPU.
are no longer addressed by the
CPU.
Output modules output the
configured substitute or holding
values.
are not addressed by the CPU. as for added I/O modules (see above)
One-sided I/O of new master
CPU
The output modules temporarily output the configured
substitution values.
are given new parameter
settings and updated by the
1)
CPU.
System modifications in operation
14.5 Adding components in STEP 7
Switched I/O
continue operation without
interruption.
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