Siemens SIMATIC S7-400H System Manual page 131

"Functional I/O redundancy" block libraries
The "Functional I/O redundancy" block libraries that support the redundant I/O each contain
the following blocks:
● FC 450 "RED_INIT": Initialization function
● FC 451 "RED_DEPA": Initiate depassivation
● FB 450 "RED_IN": Function block for reading redundant inputs
● FB 451 "RED_OUT": Function block for controlling redundant outputs
● FB 452 "RED_DIAG": Function block for diagnostics of redundant I/O
● FB 453 "RED_STATUS": Function block for redundancy status information
Configure the numbers of the management data blocks for the redundant I/O in HW Config
"Properties CPU -> H Parameter". Assign free DB numbers to these data blocks. The data
blocks are created by FC 450 "RED_INIT" during CPU startup. The default setting for the
numbers of the management data blocks is 1 and 2. These data blocks are not the instance
data blocks of FB 450 "RED_IN" or FB 451 "RED_OUT".
The blocks you use for module-oriented redundancy are located in the "Redundant IO (V1)"
library under STEP 7\S7_LIBS\RED_IO.
The blocks you use for channel-oriented redundancy are located in the "Redundant IO CGP"
library under STEP 7\S7_LIBS\RED_IO.
You can open the libraries in the SIMATIC Manager with "File -> Open -> Libraries"
The functions and use of the blocks are described in the corresponding online help.
NOTICE
Block libraries
Only use modules from one or the other library. The simultaneous use of blocks from both
libraries is not permitted.
Switching from module-oriented redundancy to channel-oriented redundancy
To activate channel-oriented passivation, you have to stop the automation system (memory
reset and reload user program in STOP).
Note the following points:
Mixing blocks from the "Redundant IO (V1)" and "Redundant IO CGP" libraries in one CPU is
not permitted, and can lead to unpredictable behavior.
Expand existing projects either with blocks from the "Redundant IO (V1)" library or switch
completely to the "Redundant IO CGP" library.
When converting a project, make sure that all library blocks named FB450-453 and FC450-451
have been deleted from the block folder and replaced by the blocks from Red-IO CGP.
Perform this step in every relevant program. Compile and load your project.
S7-400H
System Manual, 09/2007, A5E00267695-03
Using I/Os in S7-400H
10.5 Connecting redundant I/Os
131