Rockwell Automation 42CRC User Manual
Allen-Bradley
User’s Manual
PHOTOSWITCH
42CRC Color Registration Control
(Cat. No. 42CRC-4000, 4001)
Table
of Contents
Title Page
Description 1,2............................................
Installation
a. Lens Location 2.....................................
b. Mounting 2.........................................
c. Wiring 3...........................................
Alignment
a. Opaque Web Material 3...............................
b. Opaque Non-Reflective Web Material 3...................
c. Transparent Web Material
with Dark Opaque Mark 4.............................
Operating Modes
a. Latch 5............................................
b. Non-Latch 5........................................
c. Light or Dark Mark Sensing 5..........................
d. Automatic Operation 5................................
e. Manual Operation 5..................................
f. Red and Green Light Sources 6.........................
Additional Features
a. Output Dwell 7......................................
b. Gated Operation 7....................................
c. Diagnostic Alarm Output 8.............................
d. Contrast Check 9.....................................
Operation 10.............................................
Maintenance 11...........................................
Specifications 11..........................................
a. Outline Dimensions 13.................................
b. Internal Schematic 13..................................
c. Diagnostic Resistor Selection 14.........................
d. Cable Color Coding 14.................................
e. Wiring Diagrams 15, 16...................................
f. Performance Curves 17.................................
Publication PA-8853 — February 1994
42CRC Color Registration Control
1
Description
The Photoswitch Type 42CRC Series 4000 LED Color Registration Mark Control
with Automatic Gain Control (AGC) is a fixed focus diffuse-reflective scanning
device designed to detect pre-printed registration marks against contrasting
backgrounds. Detection of the marks is achieved by sensing the difference in the
gray-scale response to the mark and background.
This device has two sources of emitted light, a red and a green LED that
are selected by an operating-mode switch. The choice of a red or green
LED broadens the control’s capability of detecting a wide range of mark
and background colors.
A small light spot is projected on the material being scanned. The reflectivity of the material at the spot defines the level of the received signal.
Changes in the reflectivity, due to the contrast between the printed mark
and the background is recognized by the control, which provides an output.
This output can then be used by the packaging machine to properly cut,
seal, crimp, or fold packages or tubes.
The 42CRC Series 4000 also has a number of unique features that enhance
flexibility and reliability.
S An automatic gain sensitivity control permits fully automatic operation
eliminating the need for constant operator interface when mark to background colors change.
S A manual sensitivity selection mode enables the operator to fine tune the
control to detect poor quality marks.
S A built-in diagnostic system provides early-warning alarm indication of
gradual loss of operating margin due to changes in contrast, misalignment, or dust prior to loss of output signal, avoiding unexpected process
disruption.
S Custom microcircuitry for very high sensitivity and increased intelli-
gence in a small workable package.
S Fast 250 microsecond response time.
S Latch or automatic reset functions.
S Adjustable output dwell time.
S Selectable light or dark mark detection.
S Continuous output short circuit protection.
S Reverse polarity protection.
2
42CRC Color Registration Control
Description
(Continued)
S An external gate input makes it possible to blind the control during por-
tions of the machine cycle, eliminating the possibility of false signals
between registration marks.
S Analog test points allow evaluation of mark contrast prior to running a
machine, and three LED status indicators provide setup ease and
accuracy.
S Quick Disconnect design for ease of installation, reduced downtime and
replacement cost.
S NPN or PNP outputs. Model 4000 has one NPN (sinking) output rated
100mA at 30 VDC. Model 4001 has one PNP (sourcing) output rated
100 mA at 30 VDC. Both models have a separate diagnostic NPN
(sinking) output rated 30 mA at 30 VDC.
S Rugged high impact housing is constructed of #380.0 cast aluminum,
anodized and epoxy coated for maximum corrosion resistance.
S Entire control is rated for NEMA 3, 4, 6P, 12 and 13, IP67 (IEC 529).
Installation
a. Lens Location
For increased flexibility the lens of the 42CRC is interchangeable with the
lens cap. Determine which lens location is best for your particular application, taking into consideration the accessibility to the control adjustments
and the visibility of the indication lights. When the lens location has been
determined, make sure to tighten the lens and cap to effectively maintain a
watertight rating.
b. Mounting
The control must be mounted on a firm stable surface or support. A mounting which is subject to excessive vibration or shifting may cause unreliable
operation.
This control is designed to detect a mark at a fixed distance from the lens.
Mount the control .5 inches (13 mm) from the web to the center of the face
of the lens, with the light spot centered on the mark. Web flutter must be
held to a minimum to maintain the sensing distance within the +/-- .08 (2
mm) depth of field. To ensure reliable operation, mount the control where
the web material travels smoothly over a plate or roller with little flutter
and where there are no web creases or wrinkles. See Page 3, Figure 1.
42CRC Mounting
42CRC Color Registration Control
42CRC
WEB MATERIAL
MOUNT THE 42CRC OVER A PLATE OR ROLL TO
PREVENT FALSE SIGNALS DUE TO WEB FLUTTER
FIGURE 1
3
Installation
(Continued)
Alignment
c. Wiring
For proper wiring the 42CRC requires a Photoswitch Cable Assembly
#60-2292 ordered separately. The control operates on 10-30 VDC @ 70
mA max. See pages 11 and 12 for complete specifications. All external
wiring should conform to the National Electric Codes and applicable
local Codes. See wiring diagrams beginning on page 15 for external
connections.
The 42CRC is designed to perform reliably on many different types of web
material. However, once the device is mounted and wired, it should be
aligned to the particular web material for optimum performance and
reliability.
Most marks can be detected by using the following mounting and alignment methods. Difficult mark colors and some foil material may require
the use of the Test Points on the control to determine the best position for
maximum mark to background contrast (see Page 9, d., Contrast Check).
a. Opaque Reflective Web Material
For sensing light or dark registration marks on opaque reflective surfaces,
mount the control .5 (13 mm) above the surface of the material. If the surface is shiny or reflective, angle the control about 10 to 15 degrees to the
perpendicular (75 to 80 from the control to the web surface). See Figure
2, Page 4.
b. Opaque Non-Reflective Web Material
For sensing light or dark registration marks on material with non-reflective
surfaces, mount the control .5 (13 mm) from the surface and perpendicular (90) to the web. See Figure 3, Page 4.
4
42CRC Color Registration Control
Alignment
c. Transparent Web Material With Dark Opaque Mark
(Continued)
For this type of material, mount the control .5 (13 mm) above the web
surface and at a 10 to 15 degree angle to the perpendicular (75 to 80 from
the control to the web surface). A light colored plate or roller must be
mounted directly behind the transparent web material.
The control will see through the transparent web, sense the light colored
background providing the required contrast to the dark opaque registration
mark. See Figure 4.
42CRC Alignment
OPAQUE REFLECTIVE WEB MATERIAL
WITH LIGHT OR DARK REGISTRATION MARKS
42CRC
SCANNING DISTANCE
.5 (13mm)
75 TO 80
OPAQUE NON-REFLECTIVE WEB MATERIAL
WITH LIGHT OR DARK REGISTRATION MARKS
42CRC
SCANNING
DISTANCE
90
.5 (13mm)
WEB MATERIAL
PLATE
MOUNT THE 42CRC AT A 10 TO 15 DEGREE ANGLE
FOR REFLECTIVE (SHINY) WEB SURFACES.
FIGURE 2 FIGURE 3
TRANSPARENT WEB MATERIAL WITH DARK
OPAQUE REGISTRATION MARKS
75 TO 80
PLATE
MOUNT THE 42CRC AT A 10 TO 15 DEGREE ANGLE.
MOUNT A PLATE MADE OF A LIGHT COLORED MATERIAL
BEHIND THE TRANSPARENT WEB MATERIAL.
WEB MATERIAL
PLATE
MOUNT THE 42CRC PERPENDICULAR TO THE WEB
FOR NON-REFLECTIVE (MATTE) WEB SURFACES
42CRC
SCANNING DISTANCE
.5 (13mm)
TRANSPARENT
WEB MATERIAL
FIGURE 4
42CRC Color Registration Control
5
Operating Modes
After the control has been installed and aligned, it must be set for the
particular operation. An important feature of the control is that it gives the
user complete flexibility to select any combination of the four major
operating modes listed below via a convenient external function selector
switch. See Figures 5, 6, and 7.
a. Latch Operation
This function allows the user to latch the switched output “ON” for an indefinite period when a mark is detected. The output is reset by applying a
positive 4 to 30 VDC to the “white” GATE/RESET input lead or by simply
switching this lead to the B+ supply. Electromechanical or solid state contacts can be used to reset the control. This function enables the output duration to be extended, and the output reset later in the machine cycle. The
“Latch” switch positions are “A” through “D”.
b. Non-Latch
In the non-latch mode, detection of a mark turns the switched output “ON”
for an adjustable dwell time of up to 250 milliseconds. After the dwell
time, the output will automatically reset. This mode is similar to an adjustable one-shot. Non-latch positions are “E through H”.
c. Light and Dark Mark Sensing
The 42CRC can be set to energize on the leading edge of light marks on a
dark background or the leading edge of dark marks on a light background.
The alphabetic positions on the function switch have letters with white
backgrounds and letters with black backgrounds. Select white background
positions for light mark sensing and black background positions for dark
mark sensing.
d. Automatic Operation
“Automatic” mode provides stable, adjustment-free sensing for most applications. The 42CRC automatically adjusts the sensitivity, compensating
for variations in background colors and lens contamination. It also provides
additional gain for the low contrast marks on dark backgrounds and scanning of glossy surfaces at an angle.
In this position the orange LED marked “AUTO” is “ON” and the manual
sensitivity adjustment is NOT functional. Switch positions for this mode
are A,
A
,C,C,E,E,G,G.
e. Manual Operation
This operating mode extends the control’s sensing capability for very low
contrast marks (e.g., pastel colors) on light backgrounds. Signal processing
in the 42CRC continually corrects for variations in background signal
level. The result is a mark detection system that has a more stable threshold
6
42CRC Color Registration Control
Operating Mode
(Continued)
level, and is easier to set up in the manual operation mode. The control
must be set in the manual mode when the “test points” are used to check
for sufficient sensing contrast (see “Contrast Check” on page 9.) In this
position the orange LED marked “AUTO” will be “OFF” and the manual
sensitivity adjustment is functional. Switch positions for this mode are B,
B
,D,D,F,F,H,H.
f. Red or Green Light Sources
The 42CRC Control has both a red and a green LED light source. The
function switch permits selection of one or the other LED. The LED selection guide, Figure 8 on page 9, lists which LED to use with some basic
mark and background color combinations.
To select the proper light source for colors not listed in Figure 8, make a
Contrast Check as described on page 13. Test the mark/background with
each LED and select the one that provides the maximum mark to background voltage change.
The red LED corresponds with switch positions A,
F
. The Green LED corresponds with switch positions C,C,D,D,G,
G
,andH,H.
A
,B,B,E,E,andF,
AUTOMATIC/MANUAL
INDICATOR
ORANGE LED
“ON” IN AUTOMATIC
MODE
MARGIN INDICATOR
GREEN LED
“ON” WHEN OPERATING
MARGIN IS AT
LEAST 2 TO 1
OUTPUT INDICATOR
RED LED
“ON” WHEN THE CONTROL
OUTPUT IS “ON”
AUTO
MARGIN
SIGNAL
TEST POINTS
INTERCHANGE
LENS AND CAP
TO CHANGE
SENSING DIRECTION
TEST POINTS
TO CHECK
MARK CONTRAST
QUICK-DISCONNECT
Cable Assembly
SENSITIVITY
ADJUSTMENT
(MANUAL MODE)
5
4
3
SENS
PHOTOSWITCH
COLOR
REGISTRATION
CONTROL
42CRC--4000
SUPPLY
4D30vDC 70MA MAX
OUTPUT
100MA30VDC MAX
N.O.NP N51NK
20MA30VDC MAX
ALARM
SCANNING
WHITE-GATE (-) / RESET (+)
ORANGE-DIAG. ALARM
BLACK-NEGATIVE
RED-POSITIVE
BLUE-OUT PUT
OUTPUT DWELL TIME
ADJUSTMENT
(NON-LATCH MODE)
MODE
7
8
6
9
0
2
1
2
A
A
1
H
3
B
H
0
4
B
G
C
G
F
F
E
E
D
D
C
9
DWELL
5
6
7
8
FUNCTION SELECTOR SWITCH
FIGURE 5
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