Block Library “Functional I/O Redundancy”; Redundant I/O In Single Mode - Siemens SIMATIC S7-400H Manual

4. Redundant I/O on an H CPU in single mode
Figure 7-6
Block library "Functional I/O Redundancy"
The "Functional I/O Redundancy" block library, which is supplied with the optional
H package and offers support for redundant I/O, contains the following blocks:
• FC 450 "RED_INIT": Initialization function
• FC 451 "RED_DEPA": Trigger 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
After installation of the H option package the block is located in the library
"Redundant IO(V1)" under STEP 7\S7_LIBS\RED_IO. The functionality and use of
the blocks are described in the corresponding online help.
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
Redundant module pair

Redundant I/O in single mode

Using I/O on the S7-400H
7-13