Siemens SIMATIC S7-400H Manual page 262

Modifying the System During Operation
Table 11-1 Modifiable CPU parameters, continued
Fault-tolerant parameters
The new values are to be chosen to suit both the user program currently loaded
and the new user program planned.
Initial situation
The fault-tolerant system is working in redundant system mode.
Procedure
To change the CPU parameters of a fault-tolerant system the steps listed below
are to be performed. Details of each step are listed in a subsection.
Step
A
B
C
D
E
11-42
Tab
Test scan cycle time
maximum scan-cycle time extension
Maximum communication delay
Maximum retention time for priority classes > 15
minimum I/O retention time
What Has To Be Done?
Changing the CPU Parameters Offline
Stopping the Standby CPU
Loading Modified CPU Parameters in the Standby CPU
Switch to CPU with modified configuration
Transition to Redundant System Mode
Modifiable Parameter
Automation System S7-400H Fault-tolerant Systems
Refer to Section
11.6.1
11.6.2
11.6.3
11.6.4
11.6.5
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