Siemens SIMATIC S7-400H System Manual page 132

Using I/Os in S7-400H
10.5 Connecting redundant I/Os
Using the blocks
Before you use the blocks, configure the redundant modules as redundant in HW Config.
Link the blocks from the "Redundant IO" library into the OBs in which the redundant modules
are addressed.
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.
The valid values that can be processed by the user program are always located at the lower
address of both redundant modules. This means that only the lower address can be used by
the application; the values of the higher address are not relevant for the application.
Note
Use of FB 450 "RED_IN" and 451 "RED_OUT" when using process image partitions
You use a separate process image partition for each priority class you require
(OB 1, OB 30 ... OB 38).
132
OB
OB 72 "CPU redundancy error"
•
FC 450 is only executed after start event B#16#33:
"Standby-master changeover by operator"
OB 80 "Timeout error"
•
FC 450 is only executed after start event B#16#0A:
"Resume RUN after reconfiguring".
OB 100 "Warm restart"
•
OB 102 "Cold restart"
•
Call FC 450 in OB 80 if you connect redundant I/O to a fault-tolerant
CPU operating in stand-alone mode.
When you call FC 451 in OB 83 after inserting modules, this function
allows automatic depassivation after repairs (optional).
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 "Insert/remove module interrupt"
•
OB 85 "Program execution error"
•
Call FB 452 in OB 83 if you connect redundant I/O to a fault-tolerant
CPU operating in stand-alone mode.
System Manual, 09/2007, A5E00267695-03
S7-400H