Rockwell Automation 45LFM Capacitive Label Sensor - Manual (Page 3)

3
Adjusting Gain and Zero
These sensors are extremely stable and should not require adjustment after the initial setup. Adjustment will only be required
for significant changes in label shape or thickness, or changes in power supply voltage.
1. Remove all material from sensor.
2. Center GAIN ADJUST
Turn GAIN ADJUST four
(4) turns counter clockwise.
Turn GAIN ADJUST two
(2) turns clockwise.
3. Set ZERO ADJUST
Set ZERO ADJUST to the
point where the ZERO light
starts to come on.
4. Set GAIN ADJUST
Insert material into sensor.
While moving labels through
the sensor, Set GAIN ADJUST
to the point where the EDGE
light starts to flash. Then
continue turning 1/2 turn
clockwise.
5. Sensor is now ready for use.
How GAIN and ZERO adjustments affect the 45LFM–CMBA1–D5
The 45LFM–CMBA1–D5 is a dual capacitor type sensor.
Labels pass or move in the direction from C1 to C2 or vise
versa. The common plate of both capacitors is the base plate
that makes up the c-frame of the sensor. The electronics in
the sensor measure the difference between C1 and C2,
analog voltage = C1 – C2, which makes this sensor a
differential type sensor.
Base plate of
45LFM-CMBA1-D5
C1 C2
When common material, web and label, is under both plates
C1 = C2 and the internal analog signal is 0 Volts. Also when
nothing is place in the sensor C1 = C2. When you press on
the BASE PLATE of 45LFM–CMBA1–D5 sensor and change
the gap of the sensor C1, for the most part, = C2. As material,
web and labels, pass through the sensor, it is the fact that the
gap of the label goes under C1 first that causes the analog
voltage to increase. Once the gap of the label is between C1
and C2 and common material is again under both capacitors,
the analog voltage returns to 0V. As the gap of the label
passes under C2, the analog voltage decreases. As common
material returns under both capacitors the analog voltage
returns to 0V. This 0V is the internal supply voltage and is not
the 0V supplying the power to the sensor.
Flash start plus 1/2 turn