Rockwell Automation 45LFM Capacitive Label Sensor - Manual (Page 4)

4
The gain adjustment is required in order to be sure the analog
voltage goes beyond two trip points. The first trip point is a
positive voltage point and turns the output on when the
analog voltage exceeds the trip voltage. While the second trip
point is a negative voltage point and turns the output off when
the analog voltage goes below the negative trip voltage. Things that affect gain are: size of labels, both thickness and
width, and power supply voltage. Powering the sensor with
12V requires increased gain than when powering the sensor
with 24V. Thinner labels also require more gain for proper
detection. Too much gain can cause the sensor to pick up
certain types of ink on the label and cause false detection.
Output Polarity and Signal Waveforms
Output polarity is effected by the direction of label movement. Waveforms shown are for label movement shown in diagram.
Reversing label direction will invert waveforms.
Output Output Polarity
NPN Ground
NPN +Vin
PNP Ground
PNP +Vin
Dimensions—mm (inches)
SENSOR
20.3
(0.8)
140 (5.5)
25.4
(1.0)
5.1
(0.2)
7.6
(0.3)
15.2
(0.6)
Gap 0.76 (0.03)
(Adjustable)
31.8
(1.25)
M4 x 17.7
(0.7) (x4)
24.1
(0.95)
30.5
(1.2)
15.2
(0.6)
Publication 75009–193–01(A)
January 2003
Printed in USA
PHOTOSWITCH R is a registered trademark of
Rockwell Automation.