Because of the variety of uses for the products described in this
publication, those responsible for the application and use of this
control equipment must satisfy themselves that all necessary steps
have been taken to assure that each application and use meets all
performance and safety requirements, including any applicable laws,
regulations, codes and standards.
The illustrations, charts, sample programs and layout examples
shown in this guide are intended solely for purposes of example.
Since there are many variables and requirements associated with any
particular installation, Allen-Bradley does not assume responsibility
or liability (to include intellectual property liability) for actual use
based upon the examples shown in this publication.
Allen-Bradley publication SGI-1.1, Safety Guidelines for the
Application, Installation, and Maintenance of Solid-State Control
(available from your local Allen-Bradley office), describes some
important differences between solid-state equipment and
electromechanical devices that should be taken into consideration
when applying products such as those described in this publication.
Reproduction of the contents of this copyrighted publication, in
whole or in part, without written permission of Allen-Bradley
Company, Inc., is prohibited.
Throughout this manual we use notes to make you aware of safety
considerations:
ATTENTION: Identifies information about practices
or circumstances that can lead to personal injury or
!
Attention statements help you to:
death, property damage or economic loss.
• identify a hazard
• avoid the hazard
• recognize the consequences
Important:Identifies information that is critical for successful
Method 2 – Brightness Compensation with Maximum SpeedB–5. . . . . . . . . . .
iii
Chapter
Chapter Objectives
Overview of Manual
A–B
1
Using this Manual
Read this chapter to familiarize yourself with the rest of the manual.
You will learn about:
• Contents of this manual
• OCR2-PAK definition
• Intended audience
• Conventions used
• Terminology
• Related publications.
The following table describes the contents of each chapter in this manual.
Manual Contents
Chapter
1Overview of this Manual
2Introduction to OCR2-PAK
3OCR2-PAK Installation
4OCR Tool ConfigurationDescribes how to setup an OCR tool.
5Creating Inspection Fonts
6Using OCV
7Inspections
8Communications and I/O
TitlePurpose
Introduces you to the OCR2-PAK
software package and provides you with
a list of related documents and
conventions.
Describes key features, specifications,
restrictions, and other application
considerations.
Provides instructions for installing
OCR2-PAK.
Describes how to train OCR2-PAK to
recognize characters.
Describes how to configure and test
match strings for OCV.
Describes how to perform Test and
On-Line inspections.
Describes how to access OCR results
and perform configuration functions
through a CVIM2 communications port.
Glossary
Index
1–1
Chapter 1
Using this Manual
OCR2 PAK Definition
Intended Audience
Conventions
OCR2-PAK (Catalog No. 5370-OCR2) is an enhancement to the CVIM2
(Catalog No. 5370-CVIM2) inspection tools that provides Optical Character
Recognition (OCR) and Optical Character Verification (OCV).
OCR2-PAK is installed in the CVIM2 using a memory card. With
OCR2-PAK installed, OCR is listed as an additional selection in the CVIM2
Tool Types panel. All parameters for an OCR window are configured
through popup menus using a light pen or mouse (trackball).
No special knowledge is required to use OCR2-PAK. However, you must
understand how to configure and operate the CVIM2. Refer to the user
manuals (see related publications, next page).
This manual uses the following conventions:
• “Mouse button” refers to the left mouse button.
• References to “Mouse” are synonymous with ”Light Pen” in this manual.
• If a menu command, button or check box is grayed out or shaded that
item is not available for use at that time.
• Click means to position the cursor in the specified area and press / release
the mouse button without moving the mouse.
• Choose means to perform a menu command or check a check box.
• Select means to highlight a selection from a list or series.
• Dragging or Drag (Mouse) is performed by pointing to an object,
pressing the mouse button and holding it down while moving the object.
• Dragging or Drag (Light Pen) is performed by positioning the light pen
tip over an item on the screen and pressing the tip against the screen until
a cross (+) symbol appears. Release the light pen tip from the screen,
then drag the item across the screen. Press and release the tip against the
screen when the item is at its final position.
• Toolset refers to a set of one or more tool types that are assembled to
perform an inspection. The CVIM2 system can run one configuration
(file) at one time, and that configuration file may contain up to six
toolsets, each of which can contain one or more tools.
• Tool refers to any of the tool types, such as “gage,”“window,” and so on.
In this context, the OCR tool is just one of the tool types that a toolset
may contain.
1–2
Chapter 1
Using this Manual
Terminology
Related Publications
This manual contains some terms that you may not be familiar with.
Use the glossary at the back of this manual for assistance.
The following table lists related publications. We recommend that you read
the CVIM2 Reference Manual (Catalog No. 5370-801) before using the
OCR2 package.
OCR2-PAK is an enhancement to the CVIM2 that provides Optical Character
Recognition (OCR) and Optical Character Verification (OCV). After
OCR2-PAK is installed, OCR is listed as an option in the Tool Types panel.
An OCR Tool can be used in two ways:
• OCR mode reads characters within the tool’s processing window. It does
not use a match string to verify what text is present.
• OCV mode reads characters within the tool’s processing window, and
compares the text read to a match string entered by the user.
Both OCR and OCV have standard and strict operating modes. These modes
determine how the OCR2 package handles printed characters that correlate
with two or more different taught characters.
2–1
Chapter 2
Introduction to OCR2-PAK
Tool Panels
New tool panels are created when OCR2-PAK is installed. There are three
basic panels for OCR2-PAK:
Use the Edit OCR Tool Panel to configure an OCR Tool.
Use the Edit Font panel to add, remove, and test characters from a font list.
2–2
Use the Define Character panel to teach and test a single character.
Chapter 2
Introduction to OCR2-PAK
Font Training
Multiple Strings
Setup of the OCR Tool for inspections requires that you teach or train the
CVIM2 to recognize your set of characters (font). This means that you can
train the OCR2 package to recognize just about any character.
When you train the system, all of the taught letters, numbers and symbols are
stored as a group called a font. Fonts can be copied, edited or deleted from a
font listing.
An OCR Tool can inspect up to 4 strings of up to 20 characters each. Each
string can have its own OCR or OCV operating parameters assigned.
OCR Tool Window
Net wt. 13oz 382g
Expiration Date 3/94
Code 123456 Lot #3
Made in USA
String #1 OCV Inspection
checks for presence of string.
String #2 OCR Inspection
reads expiration date.
String #3 OCR Inspection
reads code and lot number.
String #4 OCV Inspection
checks for presence of string.
2–3
Chapter 2
Introduction to OCR2-PAK
Character Requirements
The following requirements must be met for character recognition.
Character Orientation and Direction
The OCR Tool inspects only horizontal strings. If your characters are
rotated, you can use the Build Reference Tool as described in the CVIM2
Reference Manual to rotate the OCR Tool prior to inspection.
Vertical String
Bottom-to-Top Orientation
Tool must be Rotated -90_
Vertical String
Top-to-Bottom Orientation
Tool must be Rotated +90_
Non-Recognizable Orientation As Single String
Horizontal String
Note: The Non-recognizable example above could be inspected using 3
strings in one OCR Tool.
Character Height
It is recommended that the height of the characters in the inspected image
be at least 24 pixels. Although it is possible to read characters which are
smaller, the reliability of the inspection may be reduced. For best
reliability, the characters should be at least 32 pixels high. Characters may
be as tall as desired.
The inspected characters must be approximately the same height from
inspection to inspection, but the OCR Tool can be reconfigured to handle a
change in character size. If text appears in more than one size on a single
image, different OCR Tools, with different character sizes, must be used.
Thinning of the taught character may provide some tolerance to small
changes in size. If all of the inspected characters are increased or decreased
in size by the same amount, you can use the Rescale function to reconfigure
the tool to the new character height. This eliminates the need to re-teach a
font when the height of the inspected characters changes.
2–4
Chapter 2
Introduction to OCR2-PAK
Character and String Spacing
When characters are taught, you use a Character Spacing box to set the
distance between the centers of characters, both horizontally and vertically.
No spacing between characters is required, however, characters should not
overlap.
A B C D
Character Spacing Box sets both
average distance between strings
and average distance between
characters.
The size of spaces between characters is defined by the Space Dimension
box. This is used to detect spaces between characters.
E F G H
A C D
Space Dimension box sets the
size of a space between adjacent
characters.
Character Alignment
Vertical Alignment
Characters within a string are considered part of the same string if the
vertical distance between adjacent correlation boxes is less than 1/2 the
height of the Character Spacing Box. If the distance is greater than 1/2 the
Character Spacing Box, the character is part of another string. For optimum
reliability, all of the characters in the string should be aligned vertically so
that at least 50% or more of the characters overlap.
Spacing is greater than 1/2 the height of
the character size box. This is seen as
2 separate strings: ABC F / DE.
Character
Spacing Box
E F G H
2–5
Chapter 2
Introduction to OCR2-PAK
Character Separation
Characters are considered separate characters if the distance between the
1
correlation boxes is equal to or greater than
/2 the width of the Character
spacing box. If the distance between the correlation boxes of two characters
is less than 1/2 the width of the character spacing box, the OCR Tool will
treat the two characters as a single ”confusion character” and in most cases
the tool will fail.
Space is less than 1/2 Character Spacing
Box. The C and 1 will not be seen as
separate characters.
Character
Spacing Box
Spaces
When the distance between two printed characters is greater than the
Character Spacing plus 1/2 the Space Dimension, a space is inserted into the
read string.
Space is greater than the Character
Spacing plus 1/2 the Space Dimension.
A space will be inserted.
Character
Spacing Box
When the distance between the first or last characters and the left or right
window boundary respectively is greater than the Character Spacing plus 1/2
the Space Dimension, a space is inserted before or after the read string.
Tool Window
2–6
Spacing is greater than the Character
Spacing plus 1/2 the Space Dimension. A leading space will be inserted.
No space inserted.
Chapter 2
Ñ
ÑÑÑ
ÑÑÑ
ÑÑÑ
ÑÑÑ
ÑÑÑ
Ñ
Introduction to OCR2-PAK
Gray Spaces
If the Gray Space option of the OCR Tool is enabled, each region of the
image where a space is detected will be examined to determine the
percentage of white pixels in the region. If the percentage exceeds a
user–defined value, the space is called a white space. Otherwise, it is
called a gray space, which indicates that it contains printing which is not
recognizable as a character.
If the space between the tool window and the character string is large
enough, the OCR Tool will also check for gray spaces in the regions
immediately to the left and right of a string of printed characters.
This enables the system to detect extra printing before or after the
inspected string.
Character Rotation
If you expect the characters to rotate from inspection to inspection, you can
use reference tools to correct for character movement and rotation within the
field of view.
Some rotation may be acceptable without using a reference tool, if the
characters were taught using the Thinning option.
= Character
= Character
= Taught Pixel Pattern
= Taught Pixel Pattern
Original Taught PatternThinned Pattern
A rotated character with
un-thinned pattern may not correlate.
A thinned pattern is
more tolerant to character rotation.
2–7
Chapter 2
Introduction to OCR2-PAK
Character /
Background Contrast
Ambiguous Characters
The contrast between the inspected characters and the surrounding
background must be great enough so that, when configuring the OCR Tool, a
threshold can be set to effectively distinguish the inspected characters from
the background.
Good ContrastPoor Contrast
There are several valid characters that can confuse OCR systems. Some
numbers can be misread as letters and some letters can be read as numbers.
Misreads are more likely to occur when the print quality is poor. The most
ambiguous number and letter pairs are:
NumberLetter
0
1
2
5
8
O
I
Z
S
B
Character Quality
To prevent confusion between these characters, we recommend that you:
• If possible, don’t use ambiguous characters in the same string.
• Use a different font. Some fonts have very little differences between
characters. For example, in the Courier font the lowercase L (l) and the
number (1) 1 are almost identical.
• Train the character templates carefully to reduce confusion between
similar characters.
The quality or clarity of the inspected characters affects the success of the
character recognition. Extra markings or breaks in characters can result in
failed or incorrect recognition of a character. You must determine if the
variation in characters is acceptable and adjust the taught font characters
accordingly.
2–8
Chapter 2
Introduction to OCR2-PAK
Other
Character Restrictions
The following are some additional OCR Tool restrictions. However, these
restrictions are unlikely to be encountered in most applications.
• There is a maximum of 4 ambiguous (confused) characters per character
location in a string.
• Maximum number of spaces = 32. This includes leading, internal, and
trailing spaces for all strings in the inspection window. Additional spaces
are ignored.
• Maximum number of character strings in the tool window = 4.
2–9
Chapter
Chapter Objectives
OCR2-PAK Installation
A–B
3
OCR2-PAK Installation
This chapter describes:
• Installing OCR2-PAK
• Accessing the OCR Tool
OCR2-PAK is provided on a memory card. You can only install OCR2
software in a CVIM2 module having Rev. B01 firmware or later.
To install OCR2-PAK:
1. Remove power from the module by turning off the power to the Pyramid
Integrator or Vision Platform chassis.
Power Switch
Power Switch
(Location Depends
Upon Version)
Archive
Memory Slot
CVIM2 in Vision Platform
2. Insert the RAM card in the CVIM2 Archive Memory slot.
3. Apply power to the module by turning on the power switch.
4. The module will boot up and begin the package loading sequence.
CVIM2 in Pyramid Integrator Chassis
Archive
Memory Slot
3–1
Chapter 3
OCR2-PAK Installation
5. While the package is being installed, you will see the following message:
Loading package MC:OCR2–B01
into
V1:OCR2–B01
6. When the Memory Active LED goes off and the screen displays the
CVIM2 power up message, the downloading is complete. Verify that the
power–up banner shows that OCR2–PAK has been installed.
On subsequent powerups, you are provided with the option to abort the
running of all installed packages:
6 seconds to package run
Accessing OCR2-PAK
Abort Package Run
If you abort the running of installed packages, the module will function as if
the packages were not installed.
Note: You only need to install the OCR2-PAK once. After installation,
OCR2-PAK remains installed for all subsequent powerups.
After OCR2-PAK is installed, OCR is listed as an option on the Tool Types
panel as shown below.
Select to Create
an OCR Tool
3–2
Chapter
Chapter Objectives
Procedure
A–B
4
OCR Tool Configuration
This chapter describes how to:
• Create an OCR Tool
• Configure an OCR Tool
The steps for creating an OCR Tool are listed below. You must perform the
steps in the same sequence. If you are using Optical Character Verification
(OCV), refer also to Chapter 6.
1)Add an OCR Tool in the toolset.
2)Edit the OCR Tool configuration.
3) Enter a Font Name.
4)Position Tool Window.
5)Set Threshold/Filter.
6)Set Character Size.
7)Enter and Teach characters.
8)Test taught characters.
9)Select string modes.
10)Enter match strings for OCV mode.
11) Select OCV options if required.
Refer to this Chapter
Refer to Chapter 5
Refer to Chapter 6
4–1
Chapter 4
OCR T ool Configuration
Adding an OCR Tool
To create an OCR Tool, choose Tools from the menu on the Toolset image
display panel. The following panel appears allowing you to add a new OCR
Tool or copy an existing one:
The following are brief descriptions of the Toolset Edit panel. Refer to the
CVIM2 Reference Manual (Catalog No. 5370-801) for detailed information
on editing a toolset.
Num
The sequence number of an inspection tool. it indicates the order in which
the CVIM2 system processes the tool number. The currently selected tool is
marked by an arrow.
4–2
Name
The inspection tool name. All tools are provided a default tool number such
as Tool 1. Clicking on the current name displays the keyboard for entering a
new name.
Type
The inspection tool type such as OCR. Clicking the tool type box for a tool
displays the edit panel for that tool.
Enabled
Indicates whether the tool is enabled, Yes or No. Yes is the default.
Ref
Use this field to select a reference tool for the purpose of providing shift
and/or rotation compensation for the selected inspection tool.
S1
use this field to select the primary image source for a tool from a camera
(such as C1) or from an image buffer (such as P1).
S2
Secondary image column is not applicable since OCR2 works with only one
image source.
Dst
Indicates the destination of the image. P1 is the default for an OCR Tool
indicating that the destination is a processed image.
Chapter 4
OCR T ool Configuration
There are two ways to add tools to the Toolset:
• one way creates a new tool
• the other copies an existing tool which is modified
To create a new tool:
1. Choose either Add " or Add # button on the Toolset panel to add a tool
above or below the currently selected [!] tool.
The following panel appears with tool type selections.
2. From the list, select OCR. Click the Done button.
An OCR Tool is added to the list in the Toolset panel.
3. To edit tools, refer to next section Editing OCR Tools.
To copy an existing tool:
1. Select the OCR Tool to be copied by clicking the number using the
mouse. The selected tool is indicated by an arrow[!].
2. Choose the Copy button and then the Paste" or Paste# button to place
the copy OCR Tool before or after the the marked [!] tool.
3. The copied OCR Tool has the same attributes as the original tool.
4. To edit tools, refer to next section Editing an OCR Tool.
4–3
Chapter 4
OCR T ool Configuration
Editing an OCR Tool
To edit a new or existing OCR Tool, click OCR in the Type column of the
tool listed in the Toolset Edit panel.
Click here to edit a tool.
The following OCR Tool Edit panel is displayed showing the current
configuration of the OCR Tool being edited.
4–4
Chapter 4
OCR T ool Configuration
OCR Tool Edit Panel
OCR Tool Edit Panel Components
The following describe the components of an OCR Tool Edit panel.
Font Name
Indicates the currently active font. No Font appears in the box until a font is
taught and added. Clicking in the Font Name box displays the FontSelection panel which allows you to select previously taught fonts or create a
new font.
Gray Spaces
A gray space is a space (leading, trailing , or between characters) that
contains a percentage of black pixels exceeding a preset limit. A white space
contains a lower percentage (usually 0%) of black pixels. The black pixel
limit is set using the Define Spacing function (see page 5–20).
If you select Yes for the Gray Space option, the OCR Tool will distinguish
between gray and white space. If you select No, all spaces are treated as
white space.
Below are examples of using the Gray Spaces option:
ABC - 123
Use gray space to detect a hyphen since
hyphens are very difficult to teach.
Match String
ABC 123 x
Use gray space to detect any marking
that trails the match string.
4–5
Chapter 4
OCR T ool Configuration
OCV Options
The Alpha, Numeric and Symbols options allow you to check for characters
not contained in a match string, when using OCV mode. Otherwise the tool
will not search for characters which are not present in the match string, and
any other characters may be read as spaces.
Enabling these options will generally increase the inspection time of the tool.
With these options disabled, OCV is faster than OCR because it can verify a
string by processing only the characters contained in the match string instead
of processing all taught characters in the font. The Gray Space option is in
most cases a faster method of detecting extra characters not present in the
match string.
Clicking on a check box selects the item.
Alpha specifies alphabetical characters (A ! Z and a ! z)
✓
Numeric specifies numeric characters (0 ! 9)
✓
Symbols selects all characters other than alphabetical or numeric
✓
characters
Align
The Align option can be enabled only when the first string Mode is OCV.
When Align is selected, the tool ignores all strings before the first string is
matched. For example, you may want to match a string of characters that
will not always appear on the first line in your window. The Align option
allows you to ignore the characters on lines above the line that contains the
first match string:
ABCD
EFGH
IJKL
MNO
Inspection Window
ABCD is ignored.
Match strings are
aligned with first
match.
Note: Even with the Align option enabled, the number of lines of characters
in the OCR Tool window is still limited to 4.
Mode
Specifies one of four operating modes: OCR, OCR Strict, OCV, or OCV
Strict. A selection of Disabled indicates that the string is not inspected.
4–6
Refer to page 4–15 for a description of the operating modes.
Chapter 4
OCR T ool Configuration
Match String
In OCV mode, the recognized characters are compared to Match Strings,
and the tool will fail if the strings do not match. If you select the match
string box with OCV mode selected, a keyboard will be displayed, allowing
you to enter a match string.
Metacharacters can be entered with the keyboard or by selecting the
metacharacter buttons at the top of the keyboard. The metacharacter buttons
include:
[A-Za-f] Any alpha
[0-9] Any number
? 0 or 1 occurrences of the preceding character
* 0 or more occurrences of the preceding character
+ 1 or more occurrences of the preceding character
| OR operation
Refer to Chapter 6 for a complete description of match strings and
metacharacters.
Subset
Subset allows you to inspect a portion of a string starting from the left or
right end. The following options are available:
• All
In this mode, all characters recognized (up to a maximum of 20) are
included in the read string.
• Left
When Left is selected and more than Len characters are recognized in a
single string, the read string will consist of the left-most Len characters
recognized.
• Right
When Right is selected and more than Len characters are recognized in a
single string, the read string will consist of the right-most Len characters
recognized.
Note: The maximum number of characters per line = 40. Any characters
over 40 per line are ignored.
Len
Applies to the Left and Right subset options. When a subset of a string is
selected you must enter the length of the subset.
4–7
Chapter 4
OCR T ool Configuration
OCR Tool Edit Panel Buttons
The following are brief descriptions of the buttons on the OCR Tool Edit
panel. Each of these functions is described in detail in the applicable section.
P&P Window
Initiates the Pick and Place function, which can move and size the OCR
Tool’s processing window.
Thresh/Filter
Displays the Threshold / Filter panel used to adjust the high/low threshold
settings and the Morph 1 filter.
Char Size
Allows you to set the size of characters within the OCR window. The
character size must be set after the threshold/filter is set and before characters
are taught.
Edit Font
Displays the Edit Font panel that allows you to teach and test OCR
characters.
Test Match
Allows you to enter a string to be tested against the current match strings.
This is used to test the operation of match strings which contain
metacharacters. Refer to Chapter 6.
Done
Exits to the Edit Toolset panel.
4–8
Chapter 4
OCR T ool Configuration
Enter a Font Name
A font is a collection of characters that have been taught and stored under a
font name.
To add a new font:
1. Click the in the Font Name box on the OCR Tool Edit panel
The Font Selection panel is displayed allowing you to add a font name.
OCR Tool Edit Panel
Click in Font Name box
Font Selection Panel
2. Click the Add button.
The keyboard is displayed allowing you to add a font name.
3. Enter a font name. A font name can be up to fifteen (15) characters, and
can consist of any alphanumeric character (A-Z, a-z, 0-9). Spaces are not
allowed. Also enter 3 character device type if not EE:. These 3
characters are in addition to the 15 for Font Name.
4. When completed select the Done button.
The entered name appears in the Font Name box. Any taught characters
will be saved under that Font Name. The font name appears as an option
in the Font Selection panel.
To add or edit characters in a font, refer to Chapter 5.
To delete a font:
Use the Filer function listed under the File menu. Refer to page 5–27
4–9
Chapter 4
OCR T ool Configuration
Position
OCR Tool Window
This window defines the inspection area of a character string (strings). Move
and adjust the window by clicking the P & P Window button on the OCREdit panel and referring to the the following:
Pick & Place
Panel
To move the Pick & Place Window
Click and hold down the mouse button in the middle of the window.
Move the mouse while holding down the mouse button and drag the
window over the characters to be read.
To size the Pick & Place Window
Click the mouse button on the corner of the window and drag the mouse
until the window encloses all the characters to be read. You can also
size the window using the arrow keys on the Pick and Place panel.
Position the window around the strings to be read, allowing sufficient
extra room to accommodate the expected movement of the strings within
the field of view. You may want to provide space before and after the
strings for leading and trailing spaces. Refer to space descriptions on
page 2–6.
4–10
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