Rockwell Automation 873P Analog or Discrete Ultrasonic Sensors - Manual (Page 4)

4
Synchronizing the ultrasonic pulses for a group of sensors
can also reduce the possibility of mutual interference. In
order for the Synchronize function to work effectively, the
sensors should be properly aligned and mounted at the
same distance from the target. For details see the
Synchronize function in the Wiring/Control Pin section.
Background Suppression
The discrete sensor models offer a background
suppression feature that allows the sensor to ignore all
objects beyond a specified distance. The user can set this
distance during installation by turning the four-turn
potentiometer at the rear of the sensor. The far limit of the
sensing range can be adjusted to detect valid targets and
ignore background targets such as the side of a conveyor.
Profile Reduction Beam Deflectors
Beam deflectors are available to reduce the mounting
profile for space critical applications that cannot
accommodate the barrel length of the sensor. They can
also be used to protect the sensor face from target
collisions. These accessories deflect the ultrasonic beam at
90_ and are available in plastic and stainless steel versions.
In addition to the profile reduction, the stainless steel
models provide mounting capability and focus the ultrasonic
beam.
Catalog Number Description
60- 2757
Stainless Steel focused beam deflector and mounting
bracket for 18mm models
60- 2758
Stainless Steel focused beam deflector and mounting
bracket for 30mm models
60- 2759 Plastic beam deflector for 18mm models
60- 2760 Plastic beam deflector for 30mm models
Stilling Tubes
For applications where the target may be a liquid with a
turbulent surface, a stilling tube can be used to diminish this
instability. The tube should have a smooth inner diameter
and its size should be a minimum of 50mm depending on
the application. The sensor should be mounted such that
the barrel is parallel to the sides of the tube but not
touching.
Publication 75009--190--01(A)
December 2002
Printed in USA