Rockwell Automation 873E RightSound Opposed Mode Ultrasonic Sensors - Manual (Page 4)

4
Application Information
Operating Distance Selection
Operating distance is defined as the distance from the emitter
face to the receiver face. The maximum operating distance is
based on installing the control in a clean environment. Normal
industrial environments actually range from moderately dusty
to extremely dirty. In these environments, greater sensor
response may be required which can be obtained by reducing
the operating distance of the control or by increasing the
volume adjustment of the emitter (turn clockwise).
Application Precautions
With very small separation between the emitter and the
receiver, it may be necessary to misalign the receiver by
about 5
_
off axis to reduce the effect of reflections.
The product may not function correctly if mounted too close to
high energy ultrasonic sources (such as ultrasonic welders or
cleaners). If such sources are present, set a blocking target
so that the red margin indicator just turns off and then activate
the welder or cleaner. If the margin indicator turns on or
flashes, greater physical separation between the sensors and
the noise source is required.
CAUTION: Care should be taken to
prevent applying force to the
emitter/receiver face. This can
damage the sensor.
Adjacent Pairs of Emitters/Receivers
When emitter/receiver pairs are used in close proximity,
precautions must be taken to prevent crosstalk (the response
of a receiver to the wrong emitter). Emitters should always be
pointed in the same direction so that the sonic beams are
parallel to each other.
A minimum spacing of 5cm (2in) must be maintained between
adjacent pairs for emitter-receiver separations of up to 15cm
(6in). Add 1cm (0.4in) of adjacent pair spacing for every
additional 10cm (4in) of emitter-receiver separation beyond
15cm (6in).
Installation
The controls should also be set up away from sources of
powerful airflow (such as fans or blowers) and away from
powerful direct heat sources (such as space heaters or open
ovens).
The control must be securely mounted on a firm, stable
surface or support. A mounting which is subject to excessive
vibration or shifting may cause intermittent operation.
Wiring
All external wiring should conform to the National Electrical
Code and applicable local codes. See wiring diagrams for
external connections.
Alignment
1. Connect load(s) to the receiver.
2. Apply 10.8–30V DC power to the emitter and receiver.
The GREEN indicator must turn ON on both emitter and
receiver.
3. Position the receiver sensing face opposite the emitter
sensing face, with a separation of no more than 30 I .
Center the acoustic beam by aligning the emitter and
receiver on the same axis.
4. If the RED indicator is ON, adjust the transmitter
SENSITIVITY until the RED indicator light turns OFF.
5. Breaking the acoustic beam with a target object will now
cause the output to switch, as indicated by the YELLOW
indicator.
In certain applications, the sensing target will break the center
of the acoustic beam, halfway between the transmitter and
receiver controls. With smaller sensing targets (a surface less
than 1/2
I wide), it may be necessary to position the
transmitter and receiver controls so that the target breaks the
acoustic beam closer to the face of the transmitter or receiver.
If the sensing target is large (a surface wider than 1
I
), greater
noise immunity may be obtained by increasing the sensitivity
setting further, but not to the point where the RED indicator
lights when the target is present.
In general, operation with the RED indicator illuminated either
when the target is present or absent should be avoided by
adjusting the sensitivity setting smaller (counterclockwise) if
the RED indicator illuminates when the target is present or
greater (clockwise) if the RED indicator illuminates when the
target is absent.
Warranty
Rockwell Automation/Allen-Bradley does not supply warranty
information with documentation that ships with products.
Warranty information can be found in the Sensors catalog in
the “General” section. This can be reached via the Internet at
www.ab.com/catalogs.
Publication 75009–119–01(C)
June 2001