Programming F-Systems
7.3 Structure of the Safety Program in S7 Distributed Safety
Safety Engineering in SIMATIC S7
7-6
System Manual, 04/2006, A5E00109529-05
F-Blocks of an F-Runtime Group
The F-blocks that the user employs in an F-runtime group are shown in the table below:
Table 7-1
Fail-safe Blocks of an F-Runtime Group
F-Block
Function
Programming
Language
F-CALL
F-block for calling the F-runtime group from the standard user
program. The F-CALL contains the call for the
F-program block and the calls for the automatically added
F-blocks of the F-runtime group.
The F-CALL is created by the user and cannot be edited.
F-CALL
F-FB/F-FC,
F-PB
The user programs the actual safety function using F-FBD or F-LAD.
The starting point for F-programming is the
F-program block. The F-PB is an F-FC or F-FB (with instance DB) that
becomes the F-PB when assigned to the F-CALL. The user can
perform the following in the F-PB:
•
Program the safety program with F-FBD or F-LAD
•
Call other created F-FBs/F-FCs for structuring the safety program
•
Insert F-blocks of the
F-Application Blocks
block container from the
Distributed Safety
F-library (V1)
•
Insert F-blocks from "custom F-libraries"
The user defines the call sequence of the F-blocks within the F-PB.
F-FBD/F-LAD
F-DB
Optional fail-safe data blocks that that can be read/write-accessed
from anywhere in the safety program
F-DB
F-I/O DB
An F-I/O DB is automatically generated for each F-I/O when the
program is compiled in
HW Config
. The user can or must access the
variables of the F-I/O DB in conjunction with F-I/O accesses.
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