Delta CS2 Technical Information

CS2 Color Scanner

A Self-Contained, Easy-To-Use Scanning/Lighting System in a

Compact Package For Production Line Automation Applications

The CS2 Color Scanner analyzes
reflected light captured by a silicon
cell.

It determines color by turning on only
the desired color at a given time using
its patented, solid-state lighting
system.

The CS2 then activates data outputs
based on the relative magnitude of the
Base color and the ratio of the Base
color and the Sense color.

Primary features

•

Fast response rate: 500
microseconds, 50 uS optional.

•

100,000 hour life LED lighting
system

•

Automatic adjustment to changing
ambient

•

Optically isolated outputs for Base
limit and Ratio limit. Analog
outputs for Base and Sense colors

•

Easy set-up using integrated bar
graph display

•

Compact size: 6 x 6.4 x 1.25"

•

Low power requirements: 24Vdc @
250 mA maximum

•

Color range options: blue to near­infrared

•

Versatility: Other options include
optimizing computer interface. Use
with rotary pulse generator to check
product or defect length, too.

Use the CS2 Color Scanner to:

•

Sort objects and compare

peeled vs. unpeeled
organic vs. non-organic
ripe vs. green
over-ripe/ro tten vs. normal

•

Detect product defects such as

stains
spills
knots
over or undercooked product

•

Align

materials
labels
packages

•

Read paint markings

where bar coding or inkjet
printing is impractical or
impossible

The CS2 detects deviations from
normal or average color, based on the
Sense/Base ratio.

It can be configured to detect either a
high or low ratio. whether that's a
feature needed to be recognized or a
product defect.

Using the narrow-line scanning area
option, a wide area up to 1.25" can be
scanned for defects or features.

Detecting green areas on carrots, knots
on wood, and burned cookies are
applications that typically use the Low
Ratio setting. Detecting white ends on
asparagus is an example of a High
Ratio setting.

Setup is a simple, three-step
process

1. Mount scanner(s)

2. Wire power & outputs

3. Adjust gains & thresholds and
you're your way to the benefits of
improved product quality. Fast!

Where to find more information

Free Sample Testing 2
How The CS2 Works 2
Using the Displays 3

Bar Graph Display 3
Status Indicators 3

Inputs and Outputs 3

Scan Cycle 3
Base & Sense Limit Outputs 4
Data Ready Output 4
External Trigger Input 4
Threshold Analog Inputs 4

Analog Outputs 4
Mounting the CS2 5
Wiring 6
Configuration 8
Adjustments 9

Color Tolerances 10

Pencil Sorting Example 10
Putting It To Work 11

Comparing Colors 11
Application Guidelines 12

Power Supplies 12

Electrical noise 1 2

Data Skew 12

Color Errors 12

Background Errors 12

Reflections 12

Intensity Variations 12

Using Multiple CS2s 12
Technical Information 14
Ordering Information 14
Company Profile 14
General Application Information 15

:

11719 NE 95th Street, Vancouver, Washington 98682-2444 [phone] Fax [phone]

[e-mail] http://www.deltacompsys.com

CS2 Color Scanner

Free Sample Testing

Delta will test your samples and tell you if your application
is a candidate for the CS2 color scanner (or another Delta
color scanning product).

This service is available to anyone with a potential
application. Simply send the samples, along with a business
card (se we can call and get a brief description of the
application) to:

Delta Computer Systems, Inc.
11719 NE 95th Streed, Suite D
Vancouver, WA 98682
Attn: Steve Nylund

If this brochure is more than a year old, please call and
cornfirm our address before sending. Please call (360)254-

8688.
After receiving your samples and discussing the application,

we will test your samples using a CS2 scanner and/or a
spectrometer. Will will then recommend a praticular
configuration for online testing.

Take advantage of the offer today. It's easy!

How The CS2 Works

The CS2 measures the difference in reflected light between
two light sources. In its standard configuration, the
reference color is 880-940nm (near-infrared) which is
referred to as the Base color. The second light source is
660nm (red) which is referred to as the Sense color. The
reflected color is measured by turning on the Base and Sense
high intensity LEDs, one color at a time, and reading a
silicon photocell. The amplified information is stored so
that the measured color information will still be present
when the LEDs are off. The LEDs are on for only about 20
microseconds out of the 500 microsecond cycle in order to
reduce power and maximize life.

Once the reflected Base and Sense color amplitudes are
stored, the current or real time-time values are subtracted
from the running averages ( running averages are derived
from the minimum color amplitudes) for each color. The
running averages change ove r time, allowing the CS2 to
automatically adjust to changes in temperature, ambient
lighting, etc., and making periodic recalibration to
compensate for these changes unnecessary.

By comparing the ratio of the Base and Sense colors, a
determination can be made as to when and where a color
deviation occurs. The CS2 can be configured to detect either
a Low or High Ratio deviation. Example applications where
the Low Ratio setting is used include detecting green areas
on carrots, knots on wood and burned cookies, while the
High Ratio setting would be used to detect white ends on
asparagus, some paint applications, eand so on. The default
setting is Low Ratio.

Delta Computer Systems, Inc.

[e-mail] http://www.deltacompsys.com

When more sophisticated filtering, thresholds, or limit
algorithms are needed, the CS2 provides an easy interface to
an optimizing computer. In addition to analog inputs to
permit control of the Base and Sense Thresholds, analog
outputs are provided for Base and Sense colors. The outputs
do not provide absolute color information, but provide
relative values that can be processed by an optimizing
computer.

, 11719 NE 95th Street, Vancouver, Washington 98682-2444 [phone] 2

CS2 Color Scanner

y

g

y

y

y

y

g

(

)

(

)

(

)

Using the Displays

LED's

LED's

Bar Graph Display

In order to make adjustment easy, the CS2 contains its own
voltmeter with a bar graph display which is visible through
the top. This display uses a "moving dot" technique where
the segment position represents the amplitude of the
reflected light.

Output Bar Graph Displa

ht bar indicates Sense Color

Bri

Green

Yellow

Less intense bar indicates Base Color

Red

The lowest voltage segments are yellow, the center green,
and the highest are red. Usually, once the Gains are
adjusted, the background intensity will be no higher than the
yellow segments and normal objects will be in the green
range. The 10th (red) segment indicates an overrange
condition; at this point the readings are invalid. The Gains
need to be set such that the highest intensity is not higher
than the 9th segment.

Both the Base color and the Sense color are simultaneously
displayed using a different intensity for each color. The
brighter LED represents the Sense color.

Status Indicators

Four indicators provide status of the digital inputs and
outputs. Indicators are lit when the condition they represent
is true (Output NPN transistor ON).

Bar Graph

TB2
TB1

Status
Indicators

Trig In

Data Read

Trig In

Base Limit

Sense Limit

Inputs and Outputs

The CS2 provides two analog and three digital outputs and
two analog inputs. The digital outputs are: Data Ready,
Base Limit and Sense Limit. All three are optically isolated
uncommitted NPN open-collector outputs.

The two analog outputs provide voltages proportional to the
real time Base color and Sense color. Updated every scan
cycle, the outputs range from 0-10V and will drive high
impedance inputs (2 kohms or higher). These outp uts are
not temperature compensated and must be used with the
appropriate software algorithms.

Scan Cycle

RPG Phase

NPN output ON

Bus

Scan Cycle

Trigger Delay Time

Data Read

Outputs Stable

Limits NPN output ON when
limits exceed setpoint

See

Note 1

Jumpers

Internal
Trigger

OR

External
Trigger
Input

Measure
Sense

Measure
Base

Data
Read
Output

Limit &
Analo
Outputs

Trigger Delay Time

(Determines Scan

Cycle Time when

using internal Data B & S Auto Restart

trigger) Ready 2 4 8

(default) 500us 110us 22us

*Special order, must

be set by factory

Note 1. When using an external trigger, the Scan Cycle Tim e i s
determined by the tim e between RPG transitions ( RPG NPN output
changes from OFF to ON). I f the time between transitions i s less
than the Trigger Delay Time, scan data will be lost.

S

B

NPN output ON

435us 110us 22us Yes
380us 110us 22us Yes
330us 110us 22us Yes Yes
275us 110us 22us Yes
220us 110us 22us Yes Yes
164us 110us 22us Yes Yes
110us 55us 22us Yes Yes Yes

*50us 25us 12us Yes Yes Yes

Delta Computer Systems, Inc.

[e-mail] http://www.deltacompsys.com

, 11719 NE 95th Street, Vancouver, Washington 98682-2444 [phone] 3

CS2 Color Scanner

Base & Sense Limit Outputs

Limit outputs provide the means to control an external
device when the setpoints are exceeded. Each is an isolated
open collector NPN output. When the limit setpoint is met
(Base color above setpoint and Sense limit below setpoint),
the NPN output is turned ON. ON current is 1.6 mA
minimum, 8 mA typical. The maximum open collector
voltage is 30VDC.

Note: If the limit outputs are connected to a high speed
input, they may need to be qualified with the Data Ready
output.

Data Ready Output

The Data Ready output should be used when the CS2 is
connected to a fast Analog-to-Digital converter. Inaccurate
readings can result if the A-D tries to read the analog color
voltages at the same time that the CS2 is updating them. By
synchronizing the external A-D converter to the CS2's
scanning cycle, this problem is eliminated.

The Data Ready output varies with the scan time. When
scanning with the internal trigger, Data is valid (Data Ready
line OFF) for approximately 110 microseconds each scan.
For high scan rates, the Data Ready NPN open collector
load resistor may need to be lowered (below 2.7k). It is a
good idea to allow 20-50% margin for gain degradation of
the opto-coupler. The ON current is 1.6 mA minimum, 8
mA typical. The maximum open collector voltage is 30Vdc.

External Trigger Input

This input allows a scanning cycle to be started by an
external signal. It is particularly useful when the scanner is
connected up to an optimizing computer. When the
scanning cycle is initiated by a signal from a rotary pulse
generator (RPG) connected to a belt or other co nveying
system, the length of objects and features detected can be
determined by counting the number o f RPG counts that
occur while the object or feature is within view of the
scanner. In this way, dimensional information can be
obtained.

To use this option, jumper the scanner for external triggered
operation, and wire the output of the RPG (or other trigger
source) to the Trig In terminals. The trigger input of the
CS2 requires 5 mA and will work with signal sources
between 3.5 and 24V, ensuring compatibility with most TTL
and open-collector encoders.

Threshold Analog Inputs

The CS2 provides two analog inputs to control the Base and
Sense limit setpoints. For applications using these inputs,
please contact Delta for assistance.

Analog Outputs

The CS2 provides two analog outputs proportional to the
real time Base color and Sense color. These outputs are
updated every scan cycle. The outputs are 0-10V and will
drive high impedance inputs ( 2 kohms or higher).

When using the analog outjputs with a PLC or other
computer, the Sense reading is divided by the Base reading
to get the Sense/Base ratio. This ratio is then compared with
a threshold value as is done within the CS2.

However, using the analog outputs allows additional
flexibility, such as multiple thresholds, thresholds that can
be stored and set remotely.

Note that is is often advantageous to subtract the
background readings before calculating ratios in cases where
the object being viewed does not completely fill the viewing
area.

Contact Delta for help with specific applications.

Delta Computer Systems, Inc.

[e-mail] http://www.deltacompsys.com

, 11719 NE 95th Street, Vancouver, Washington 98682-2444 [phone] 4

Mounting the CS2

j

The CS2 scanner is contained in a enclosure which has
mounting tabs on the bottom. The lighting LEDs shine
through the clear bottom and the optics pick up the
reflected light through the bottom also. The bar graph
display and status indicators can be viewed through the
clear top.

Mount the CS2 so that the object to be scanned is within
the scanning area. In the default configuration, the center
of the scanning range is 1.75" from the bottom of the
scanner. Although the CS2 can see to some extent from
about 1" to about 4", best performance is from 1.5 to 2".

The CS2 will operate in any position. However, in dirty
environments, it is best to have the CS2 lo oking straight
down, and worst to be loo king straight up. If the scanner
must be placed such that it is looking up, a stream of air
may be adequate to keep the window clean.

CS2 Color Scanner

It is also advantageous to be able to see the indicators
through the clear top of the unit when it is in operation.

CS2

Viewer

LEDs

Scanning Range

LEDs

Nominal Distance
from Scanner to
ob

ect

Object

Background

Scanning Area Line Orientation

P/N CS2-NR-A1X8-00

Bottom View of CS2

Object

Scanning Area

Various scanning areas and shapes are possible.
Please contact Delta for further information.

Delta Computer Systems, Inc.

[e-mail] http://www.deltacompsys.com

Top View of Scanned Area

, 11719 NE 95th Street, Vancouver, Washington 98682-2444 [phone] 5