Siemens SIMATIC S7-400H System Manual page 184

Using I/Os in S7–400H
13.4 Connecting redundant I/O to the PROFIBUS DP interface
Using the blocks
Before you use the blocks, parameterize the redundant modules as redundant in HW Config.
The OBs into which you need to link the various blocks are listed in the table below:
Block
FC 450 "RED_INIT"
FC 451 "RED_DEPA"
FB 450 "RED_IN"
FB 451 "RED_OUT"
FB 452 "RED_DIAG"
FB 453 "RED_STATUS"
To be able to address redundant modules using process image partitions in cyclic interrupts,
the relevant process image partition must be assigned to this pair of modules and to the
cyclic interrupt. Call FB 450 "RED_IN" in this cyclic interrupt before you call the user
program. Call FB 451 "RED_OUT" in this cyclic interrupt after you call the user program.
184
OB
OB 72 "CPU redundancy error" (only with fault-tolerant systems)

FC 450 is only executed after the start event B#16#33:"Standby-
master changeover by operator"
OB 80 "Timeout error" (only in standalone mode)

FC 450 is only executed after the start event "Resume RUN after
reconfiguring"
OB 100 "Restart" (the administration DBs are recreated, see the

online help)
OB 102 "Cold restart"

OB 83 "insert/remove module interrupt" or OB 85"Program

execution error"
If you call FC 451 in OB 83 while inserting modules, or in OB 85
by means of outgoing interrupt, depassivation is delayed by 3
seconds.
OB 1 "Cyclic program" and/or OB 30 to 38 "cyclic interrupt"

You must also call FC 451 conditionally in OB1 or OB 30 to 38
after having eliminated the malfunction, for example, with a user
acknowledgment. The FC 451 only depassivates modules in the
corresponding process image partition.
Depassivation is delayed by 10 seconds with Version 3.5 or higher of
FB 450 "RED_IN" in the library "Redundant IO MGP" and Version 5.8
or higher of FB 450 "RED_IN" in the library "Redundant IO CGP"
V50.
OB 1 "Cyclic program"

OB 30 to OB 38 "Cyclic interrupt"

OB 1 "Cyclic program"

OB 30 to OB 38 "Cyclic interrupt"

OB 72 "CPU redundancy error"

OB 82 "Diagnostic interrupt"

OB 83 "Swapping interrupt"

OB 85 "Program execution error"

OB 1 "Cyclic program" (fault-tolerant systems only)

OB 30 to OB 38 "Cyclic interrupt"

System Manual, 03/2012, A5E00267695-11
S7-400H