Process Diagram For Link-Up And Update; Functional Sequence Of Link-Up And Update - Siemens SIMATIC S7-400H Manual

Linking and Synchronizing

Process diagram for link-up and update

The following illustration outlines the functional sequence of link-up and update in
general terms. The starting point is with the master in single mode. In the
illustration CPU 0 is assumed to be the master CPU.
Master CPU (CPU 0)
RUN
Deletion, loading, generation and
compression of blocks are no
longer possible.
Test and commissioning
functions are no longer possible.
Comparison of memory configuration, operating system ver-
sion and FEPROM content
Copy load memory content
Copy user program blocks of main memory
Lift restrictions; catch up delayed
execution
*)
If the option "Switch to CPU with Modified Configuration" is active, no load memory
content will be copied; you can see what is copied from the user program blocks of the
main memory (OBs, FCs, FBs, DBs, SDBs) of the master CPU in Section 6.2.3.
Figure 6-1

Functional sequence of link-up and update

6-4
Link-up
(REDF LEDs flash at 0.5 Hz)
Standby requests LINK-UP
*)
Assumption of the connections
Update
see Figure 6-2
Redundant system mode or master/standby switch-
over with new standby put into STOP mode
Standby CPU (CPU 1))
STOP
Deletion, loading, generation and
compression of blocks are no
longer possible.
Test and commissioning functions
are no longer possible.
*)
All connections are
broken
Resumption of the DP slaves
Lift restrictions; catch up delayed
execution
Automation System S7-400H Fault-tolerant Systems
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