WAGO 8FDI 24V PROFIsafe 750-662/000-004 Manual page 122

122 Glossary
Risk Reduction
The required risk reduction is the result of a risk assessment on the basis of
which measures are taken to lower the risk of a safety system to an acceptable
residual risk.
S
Safe PLC
A safe PLC (Programmable Logic Controller) is a safety-oriented PLC that
controls safe devices, e.g., F I/O modules.
Safety Function
Function of a machine whose failure can lead to an immediate increase in the
risk(s).
Safety Response Time
The safety response time is the time between a safety request (on an
input/channel pair or in the output process values) and the response to the safety
request (in the input process values). This time is observed even in the presence
of an error. In the process image, if an error is present, the channel status bit of
the input channel in the input process image changes from status 1 to status 0
(T(SR)).
Sensor
A sensor is used for recording physical quantities (e.g., switch settings,
temperature, pressure etc.) and can be connected (if compatible) to the digital
inputs of the F I/O module.
Severity Level of Diagnostics
The severity levels of diagnostics are derived from the PROFINET system
description, according to which "Severity Level" stands for "Error" corresponding
to "Fault" and "Maintenance Demanded" corresponding to "Warning."
SIL (Safety Integrity Level)
The Safety Integrity Level (SIL) is used to assess
electrical/electronic/programmable electronic (E/E/PE) systems in terms of
reliability of safety functions. There are four levels for specifying the requirement
for the safety integrity of safety functions, where "Safety Integrity Level 4" is the
highest level of safety integrity and "Safety Integrity Level 1" is the lowest.
Single Fault Security
Even after one error occurs, the required safety function is still ensured. In other
words, one error does not lead to the loss of the safety function.
Short Circuit
A conductive connection between two live electrical lines with almost no
resistance (see also "Cross Circuit").
Manual
Version 1.0.0, valid from HW/SW Version 01/01
WAGO I/O System
750-662/000-004 8FDI 24V PROFIsafe