Banner Q60 Background Suppression Series - Manual (Page 2)

2
P/N 114348
Q60LAF Series Laser Adjustable-Field Sensors
Banner Engineering Corp. • Minneapolis MN, U.S.A.
www.bannerengineering.com • Tel: 763.544.3164
Overview
The Q60LAF sensor is a full-featured adjustable-field sensor. These adjustable-
field sensors are able to detect objects of relatively low reflectivity, while ignoring
other objects in the background (beyond the cutoff point). The cutoff distance is
mechanically adjustable, using the 2-turn adjustment screw (Figure 1). A rotating
pointer indicates the relative cutoff position. (The indicator moves clockwise to show
increasing distance.) The collimated laser emitter produces a small, bright spot,
allowing easy alignment and precision sensing of relatively small objects at long
range.
Two push buttons (ON Delay and OFF Delay) are used to set the output delay options,
to toggle between light and dark operate modes and to lock out the push buttons for
security purposes. For 10 to 30V dc models, these functions also may be accomplished
using the remote wire.
Seven LED indicators show, during RUN mode, the sensor configuration and
operating status. During Delay Configuration, 5 of the LEDs combine to form a single
light bar that indicates relative ON or OFF delay time.
Adjustable-Field Sensing – Theory of Operation
In operation, the Q60LAF compares the reflections of its emitted light beam (E) from
an object back to the sensor’s two differently-aimed detectors R1 and R2 (see
Figure 2). If the near detector (R1) light signal is stronger than the far detector (R2)
light signal (see object A, closer than the cutoff distance), the sensor responds to the
object. If the far detector (R2) light signal is stronger than the near detector (R1) light
signal (see object B, object beyond the cutoff distance), the sensor ignores the object.
The cutoff distance for Q60LAF sensors is adjustable from 200 to 1400 mm
(8" to 55") for Class 1 laser models, and 200 to 2000 mm (8" to 80") for Class 2 laser
models. Objects lying beyond the cutoff distance are ignored.
In the drawings and discussion on this page and page 4, the letters E, R1, and R2
identify how the sensor’s three optical elements (Emitter “E”, Near Detector “R1”,
and Far Detector “R2”) line up across the face of the sensor. The location of these
elements defines the sensing axis (see Figure 3). The sensing axis becomes important
in certain situations, such as those illustrated in Figures 7 and 8.
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Figure 1. Q60LAF features
Figure 3. Q60 sensing axis
R1
R2
Lenses
Object
A
Object B
or
Background
Sensing
Range
Cutoff
Distance
E
Receiver
Elements
Near
Detector
Far
Detector
Figure 2. Adjustable field sensing concept
Receiver
Elements
Emitter
Sensing
Axis
When an object approaches from the side, the most reliable
sensing usually occurs when the line of approach is parallel
to the sensing axis.