Siemens SIMATIC S7 F, Manual

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Check Lists
Fail-Safe Systems
A5E00085588-03
A-9
Block
Name
Block
Number
Function Check
F_TESTM FB 400 Switching of Safety Mode on and off
F_TI_FTI FB 368 Converts from TIME to F_TIME
F_TOF FB 344 Timer off-delay
F_TON FB 343 Timer on-delay
F_TP FB 342 Timer pulse
F_XOR2 FB 303 XOR logic operation on two inputs
F_XOUTY FB 306 Binary selection X out of Y
DB_INIT* FC 180 F-run-time group coldstart initialization logic
DB_RES* FC 301 Supports the startup characteristics in the
event of a cold restart/warm restart of the
CPU
FAIL_MSG* FC 181 F-run-time group shutdown diagnostic error
reporting
RTG_LOGIC* FB 459 F-run-time group shutdown and restart logic
interface
* Even though these blocks aren’t yellow, they are safety critical and are placed
automatically by the CFC editor. The user may not place or remove these blocks.
Changes are not permitted except for connections to the F_SHUTDN block (see
the F_SHUTDN block description in the Fail-Safe Block section for further
description).
Newly created accepted F block types can be added to the list of certified F-Blocks.