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

System modifications during operation
17.5 Adding components in STEP 7
17.5.7

STEP 7, step 7: Transition to redundant system mode

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 choose "PLC >
2. From the "Operating Mode" dialog box, select the reserve CPU, then click "Warm
Result
The reserve CPU links up and is updated. The fault-tolerant system is operating with the new
hardware configuration in redundant system mode.
Reaction of the I/O
Type of I/O
Added I/O modules
I/O modules still
present
Added DP stations
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
If one of the monitored times exceeds the configured maximum the update is canceled. The
fault-tolerant system remains in single mode with the previous master CPU and, assuming
certain conditions are met, attempts the link-up and update later. For additional information,
refer to section Time monitoring (Page 155).
308
Operating Mode" from the menu.
Restart".
One-sided I/O of reserve CPU
are given new parameter
settings and updated by the
CPU.
The output modules
temporarily output the
configured substitution values.
are given new parameter
settings and updated by the
1)
CPU.
as for added I/O modules (see
above)
One-sided I/O of master CPU
are updated by the CPU.
continue operation without interruption.
are updated by the CPU.
Switched I/O
are updated by the CPU.
Generate insertion interrupt;
must be ignored in OB 83.
System Manual, 03/2012, A5E00267695-11
S7-400H