Siemens SIMATIC S7 F, Manual

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Glossary
Fail-Safe Systems
Glossary-2
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1oo1 evaluation Type of sensor evaluation: In 1oo1 evaluation, there is one sensor and it
is connected to the module via a single channel.
Discrepancy analysis The discrepancy analysis is used to determine errors in the time
sequence of two signals with the same functionality. The discrepancy
analysis is started if different levels are detected in two associated input
signals. After a configurable interval (discrepancy time) has elapsed, a
check is carried out to establish whether the discrepancy has
disappeared. If not, there is a discrepancy error.
There are two different types of discrepancy analysis for fail-safe input
modules:
•
In the case of 1oo2 evaluation:
The discrepancy analysis is carried out between the two input
signals of the 1oo2 evaluation in the fail-safe input module.
•
In the case of redundant I/O modules:
The discrepancy analysis is carried out between the two input
signals of the redundant input modules by means of the fail-safe
driver blocks.
Discrepancy Time Configurable time for the discrepancy analysis
E
ES
Engineering system
F
F Abbreviation for fail-safe
F-Copy License Formal permission to use the CPU as an F-compatible CPU for
S7 F/FH systems.
F CPU F-capable CPU containing a safety program
F cycle time Cyclic interrupt time for OBs with F-run-time groups
F-Data Types
Fail-safe data types
F-FBs Fail-safe function blocks
F-I/Os Fail-safe Input/Output modules
F program Fail-safe user program or Safety Program consisting of the fail-safe
blocks of the "Fail-safe Blocks" library.
F-run-time groups Run-time groups in which fail-safe function blocks are called
F-SMs Fail-safe signal modules
F-Systems
Fail-safe systems
Fail-safe Capability of a technical system to remain in or revert to a safe state
immediately after certain failures occur.
Fail-safe signal modules
Signal modules that can be used for safety-related operation (safety
mode) in the fail-safe S7 F/FH systems. These modules have integrated
functions for fault/error detection and responses.
Fail-safe systems Fail-safe systems are characterized by the fact that they remain in or
revert to a safe state immediately after certain failures occur.
Fault reaction time
The time between detection of an error and arrival at a safe state.