4 Safety Program Creation - Configuration Example
This chapter describes the procedure for creating the safety program using the
SIEMENS SIMATIC Manager configuration software and the S7 Distributed
Safety optional package.
The safety program is created with the FBD/LAD Editor in STEP 7. The fail-safe
FBs and FCs are programmed in the F-FBD or F-LAD programming language, while
the fail-safe DBs are created in the F-DB programming language. The Distributed
Safety F-Library supplied by SIEMENS provides the user with fail-safe application
modules, which can be used in the safety program.
When generating the safety program, safety checks are performed automatically and
additional fail-safe blocks are integrated for error detection and error reaction. This
ensures that failures and errors are detected and corresponding reactions are
triggered, which keep the F-System in safe status or put it into a safe status.
A standard user program can run in the F-CPU in addition to the safety program. The
co-existence of standard and safety program in the F-CPU is possible, as the safety-
oriented data of the safety program are protected against undesirable influence by
data of the standard user program.
Data exchange between safety and standard user program in the F-CPU is possible
by means of flags and through access to the process image of the inputs and outputs.
Access protection
Access to the F-System S7 Distributed Safety is protected by two passwords,
the password for the F-CPU and the password for the safety program. A differentiation
is made between offline and online password for the safety program:
● The offline password is part of the safety program in the offline project on the
programming device.
● The online password is part of the safety program in the F-CPU.
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07/15/2015
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