Siemens SIMATIC S7 F, Manual

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Fail-Safe Blocks
Fail-Safe Systems
8-46
A5E00085588-03
Timing Diagram
6
9
Min. 1s
: Possible time for a signal change
IN
OUT
Q
t
Max. 1min
Max. 1min
One cycle
I/Os
Name Data Type Explanation Default
Input: IN INT Input variable from the ES 0
Outputs: OUT F_BOOL Output for acknowledgment 0
Q BOOL Status of the time evaluation 0
Error Handling
In the event of an error that is critical to safety, the system function SFC F_CTRL
is called. This records the event in the Diagnostic Buffer and requests a switch to
the reserve CPU if the error occurred only on the master CPU. For non-redundant
systems or a common-cause error occurring in both CPUs, the shutdown logic can
be configured to either disable the erred F-run-time group or the entire Safety
Program.
Error Information in Diagnostic Buffer
Error Code (W#16#...) Description
75DAH Error in the safety data format (error due to online modification
of the Safety Program or internal CPU fault)
Operation and Monitoring
Parameters IN and Q have the system attribute S7_m_c. They can therefore be
directly operated and monitored from an operator interface system (OS).