Page 68 - Sensors and Systems - North American Catalog
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Germany: +49 621 776-4411
Refer to General Notes Relating to Product Information
Pepperl+Fuchs Group
USA: +1 330 486 0001
Singapore: +65 6779 9091
Copyright Pepperl+Fuchs
Sensors and Systems
2:1 technology for NAMUR output
sensors
The patented 2:1 technology fromPepperl+Fuchs provides
potential savings of 50% on sensor wiring in hazardous areas.
Signals fromNAMUR sensors can be transmitted in pairs to a
control device via one line. This can be done through NAMUR
output sensors that have 2:1 technology or using NAMUR
output sensor without 2:1 technology and using F-KD-EX2
module. Addition information about wiring and sensors with
2:1 can be found on KFD2-SRA-Ex4 data sheets.
Two-wire NAMUR safety sensors
These proximity switches are equivalent to
NAMUR sensors, but when used with an
approved interface device, a sensor/control unit
cable malfunction can be detected; the output
of the control unit automatically goes to the safe
“OFF” state.
The model number for this type of sensor includes the
reference -SN or S1N.They are supplied as:
•
NC contact (SN)
•
NO contact (S1N)
WARNING – SAFETY INTEGRITY LEVEL (SIL)
UP TO SIL3 ACCORDING TO IEC 61508
In safety-related applications the sensor must be
operated with a qualified fail-safe interface from
Pepperl+Fuchs, such as KFD2-SH-EX1.
Consider the “exida Functional Safety
Assessment” document which is available on
as an integral part of this product’s
documentation.
Sensors with relay contact output
Some sensors have relay contact outputs. The maximum
switching power and the type of voltage can be found in the
respective data sheets. The mechanical service life data
relates to the number of switching cycles for the unloaded
relay contact output. Under nominal load conditions, it
reduces to the value specified for the electrical life. The
service life details are MTBF values.
Switching example
Three-wire DC analog sensors
These sensors have separate connections for the power
supply and the output. An analog signal output is proportional
to themeasured variable.Themost widely used analog signals
are 4 mA to 20 mA and 0 V to 10 V.
Examples of the measured variable include the object
distance, an inclination angle, a filling level, a valve position,
or an acceleration value. Most analog sensors have a
parameterization option that enables the output to be
optimally adapted to the conditions in the application.
Analog sensors often have switching outputs for signaling
threshold levels.
Switching example:
The model number for this type of sensor includes the
reference -I or -U. They are supplied as:
•
Current output, e.g., 4 mA ... 20 mA (I)
•
Voltage output, e.g., 0 V ... 10 V (U)
•
Current/voltage output with independent load detection
and function changeover (IU)
Three-wire DC sensors with frequency output
These sensors (primarily ultrasonic sensors) indicate the
measured variable within the detection area in the form of a
pulse train with variable frequency. For example, when the
fill level is Smin the frequency output supplies the lowest
frequency value; when the fill level is Smax it supplies the
highest frequency. The frequency characteristic is linear
between the measurement range limits.
Application example:
1
+U B
5
2
4
-U B
3
Program input
Analog output
Synchronization
U B
U B
1
2
3
4
5
6
A1
A2
A3
S
