Step D: Switch To Cpu With Modified Configuration - Siemens SIMATIC S7-400H Manual

10.6.4

Step D: Switch to CPU with modified configuration

Initial situation
The modified hardware configuration is loaded into the standby CPU.
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 click the Switch to button.
3. In the Switch to dialog box select the option with modified configuration
and click the Switch button.
4. Confirm the check question that follows with OK.
Result
The standby CPU connects, is updated and becomes the master. The former
master CPU switches to STOP mode, the fault-tolerant system continues to work
in Solo mode.
Behavior of the I/O
Type of I/O One-way I/O of previous
I/O modules Are no longer addressed
by the CPU.
Output modules output the
configured substitute or
holding values.
1) 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 and no change of master takes place. The fault-tolerant system
remains in Solo mode with the previous master CPU and in certain conditions
attempts to perform the change of master later. For more details refer to
Section 5.3.
If the values for the monitoring times in the CPUs are different then the higher
value always applies.
S7-400H Programmable Controller Fault-Tolerant Systems
A5E00068197-04
Modifications to the System while in Operation
One-way I/O of new
master CPU
Are re-parameterized
and updated by the CPU.
master CPU
1)
Continue to work without
interruption.
Switched I/O
10-45