System and operating states of the S7–400H
11.2 System states of the S7–400H
S7-400H
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System Manual, 03/2012, A5E00267695-11
11.2
System states of the S7–400H
11.2.1
The system states of the S7-400H
The system states of the S7-400H 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 reserve CPU is in LINK-UP mode"
we say "the S7-400H system is in link-up mode".
Overview of system states
The table below provides an overview of the possible states of the S7-400H system.
Table 11- 1 Overview of S7-400H system states
System states of the S7–400H
Operating states of the two CPUs
Master
Reserve
Stop
STOP
STOP, power off, DEFECTIVE
Start-up
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