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[email protected] • www.turck.com • 2015/02
Product description
To improve accuracy, the ultrasonic sensor forms the mean value from the measurement of several sound pulses
before outputting a new value. The ultrasound velocity depends on the composition and the temperature of
the gas in which the sound is propagated. In most ultrasound applications, the composition of the gas is stable
whereas the temperature may often fluctuate.
The speed of sound in air varies with the temperature according to the following approximation formula:
C
m/s
= 20 × √273 + T
C
C
m/s
= Speed of sound in meters per second
T
C
= Temperature in °C
Fluctuations in air temperature therefore affect the speed of sound, which in turn has an effect on the total time
for the echo measured by the sensor. An increase in air temperature shifts both measuring range limits closer to
the sensor. Conversely, both measuring range limits are shifted further away from the sensor by a drop in air tem-
perature.
This shift is approximately 3.5 % of the limit distance with a temperature change of 20 °C.
Good ultrasonic reflectors are metals, glass, stone, wood with smooth and hard surfaces, as well as liquids that are
aligned appropriately to the sensor.
Cloth, sand or grains absorb some of the sonic energy. Foams and skins are particularly poor reflectors.
4.4
Functions and operating modes
The “High-End” ultrasonic sensors can be run as diffuse mode or retro-reflective sensors. The user can set an indi-
vidual switch point as well as a window or hysteresis function. Other operating modes (opposed mode, multiplex
mode or synchronization mode) can be set exclusively via IO-Link and used.
4.4.1
Setting options
The “High-End” series ultrasonic sensors are provided with three different setting options:
■
Setting by manual bridging (shorting)
■
Setting with connected teach adapter (accessories to be ordered separately)
■
Setting via the pushbuttons
4.4.2
IO-Link operation
In IO-Link mode, the device can be parameterized from a PC via IO-Link. In addition to manually settable functions,
additional operating modes can be set via IO-Link.
4.4.3
IO-Link operation – Multiplex mode
In multiplex mode, up to 9 ultrasonic sensors of the same type may be operated at fixed intervals one after the
other without mutual feedback.
nOTE
Devices of the same type required
In order to ensure proper functioning of the Multiplex mode, all connected sensors must have the same perfor-
mance and range. Only operate sensors with the same type code in the Multiplex mode. The type code is applied
on each device, please refer to p. 6 for the declaration of the type code.
In multiplex mode, the addresses must be assigned via PACTware™. The master must always receive the highest
address; This address should be as small as possible because it gives the number of connected slaves.
Ultr
asonic sensors
“H
igh End“
