Siemens SIMATIC PCS 7 CPU 410-5H

Operator controls and operating modes of the CPU 410-5H
7.2 System states of the redundant CPU 410-5H
CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB
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7.2.2
The system states of the fault-tolerant system
The system states of the fault-tolerant system result from the operating states of the two
CPUs. The term "system state" is used as a simplified term which identifies the concurrent
operating states of the two CPUs.
Example: Instead of "the master CPU is in RUN and the standby CPU is in LINK-UP mode"
we say "the fault-tolerant system is in link-up mode".
Overview of system states
The table below provides an overview of the possible states of the fault-tolerant system.
Table 7- 2 Overview of system states of the fault-tolerant system
System states of the fault-tolerant
system
Operating states of the two CPUs
Master
Reserve
STOP
STOP
STOP, power off, DEFECTIVE
STARTUP STARTUP STOP, power off, DEFECTIVE, no
synchronization
Single mode RUN STOP, ERROR-SEARCH, power off,
DEFECTIVE, no synchronization
Link-up
RUN
STARTUP, LINK-UP
Update
RUN
UPDATE
Redundant
RUN
RUN
HOLD HOLD STOP, ERROR-SEARCH, power off,
DEFECTIVE, no synchronization