2-D Matrix Symbology - A two dimensional arrangement of contrasting marks encoding information in accordance to specific rules. The resolution of the symbol's markings is substantially equal in two orthogonal axes.

2-D Stacked Symbology - A symbology consisting of 2 or more adjacen and associated rows of varying-width parallel bars and spaces. All of the rows in a symbol are the same length.

2-Dimensional Bar Code - Two dimensional symbology composed of rows of data arranged in a rectangular or square pattern. The rows of data are stacked onto each other to encode an array of data.

Accuracy - The determination of whether any element width or intercharacter gap width (if applicable) differs from its nominal width by more than the printing tolerance.

AIM - Automatic Identification Manufacturers organization supported by manufacturers and suppliers of automatic identification products and services.
Alignment In an automatic identification system, the relative position and orientation of a scanner to the symbol.

ANSI - The American National Standards Institute, a nongovernmental organization responsible for the development of voluntary standards.

Aperture - The opening in an optical system that establishes he field of view.

ASCII - The character set and code described in American national Standard Code for Information Interchange, ANSI X3.4-1977. Each ANCII character is encoded with 7 bits. The ASCII character set is used for information interchange between data processing systems, communication systems, and associated equipment. The ASCII set consists of both control and printing characters.

Aspect Ratio -In a bar code symbol, the ratio of bar height to symbol length.

Autodiscrimination - Capability of reading and decoding more than one bar code symbology in a single piece of equipment.

Average Background Reflectance - Expressed as a percent; the simple arithmetic average of the background reflectance from at least five different points on the sheet.

Background - The spaces, quiet zones and area surrounding a printed symbol.

Bar - The darker element of a printed bar code symbol.

Bar Code - An automatic identification technology that encodes information into an array of adjacent varying width parallel rectangular bars and spaces.

Bar Code Character - A single group of bars and spaces that represents a specific number (often one) of numbers, letters, punctuation marks or other symbols. This is the smallest subset of a bar code symbol that contains data.

Bar Code Density - The number of data characters that can be represented in a linear unit of measure. Bar code density is often expressed in characters per inch.

Bar Code Label - A label that carries a bar code symbol and is suitable to be affixed to an article.

Bar Code Reader - A device used to read a bar code symbol.

Bar Code Symbol - See Symbol.

Bar Height - See Bar Length.

Bar Length - The bar dimension perpendicular to the bar width. Also called height. Scanning is performed in an axis perpendicular to the bar length.

Bar Width - The thickness of a bar measured from the edge closest to the symbol start character to the trailing edge of the same bar.

Bar Width Reduction - Reduction of the nominal bar width dimension on field masters or printing plates to compensate for systematic errors in some printing processes. Bar width reduction can have positive or negative values.

Blemish Percent - The Blemish Percent is an indication of what percent of the total measured bar height has spots or voids or is damaged with ink or toner blobs.

CCD - A Charge Coupled Device is a bar code scanner which senses the light and dark areas of a symbol.

Character - 1. A single group of bars and spaces that represents a specific number (usually one) of numbers, letters, punctuation marks, or other symbols. 2. A graphic shape representing a letter, numeral, or symbol. 3. A letter, digit, or other symbol that is used as part of the organization, control or representation of data.

Character Alignment - The vertical or horizontal position of characters with respect to a given set of reference lines.

Character Density - For a conventional single-row bar code symbol, the number of characters represented in the symbol divided by the total width of the symbol, expressed as characters per unit width (as in characters per inch, cpi). For a multi-row bar code symbol, the number of characters represented by the symbol, expressed as characters per unit area.

Character Set - Those characters available for encodation in a particular automatic identification technology.

Check Character - Those characters included within a string of data whose value is used for the purpose of performing a mathematical check to ensure the accuracy of the data.

Check Digit - A check digit serves the same purpose as a check character, but it may assume numeric values only.

Clear Area - See Quiet Zone.

Cloaking - A term used to describe placing an electronical mask over a bar code label. It is used when there is more than one bar code image in the field of view at the same time.

Codabar - A numeric only bar code consisting of seven black and white bars. Two bars are wide (Code 27).

Code 128 - A alphanumeric bar code capable of encoding all 128 ASCII characters.

Code 16K - Multi-row (stacked) code in which each symbol can have between two and sixteen rows or stacks. Each row is separated by a one module separator bar, and consists of 18 bars and 17 spaces. The code is analogous to sentences in a paragraph.

Code 39 - A full alphanumeric bar code consisting of nine black and white bars. Three bars are wide (Code 3 of 9). Code 39 is the most frequently used symbology in industrial bar code systems today.

Coercivity - Value of the opposing magnetic intensity that must be applied to a material to remove the residual magnetism when it has been magnetized to saturation.

Concatenation - The ability of a reading system to join together the data from multiple symbols and interpret it as a single message.

Continuous Code - A bar code symbology where all spaces within the symbol are parts of characters, e.g., Interleaved 2 of 5. There is no intercharacter gap in a continuous code.

CPS - Characters Per Second.

CRT - Cathode Ray Tube. Also called a terminal or monitor.

Data Matrix - Variable size two dimensional matrix symbology that is inherently omnidirectional. Data Matrix has a high degree error correction capability and is used primarily for part marking and tracking.

Decode - Each bar code symbology has a specific decode algorithm. If a symbol is decoded correctly, it will receive an "A" grade. If not, it will receive an "F" grade. The ANSI grade of Decode checks for: -Valid Characters -Correct start and stop characters (patterns) -Correct check digits (when applicable) -Legal quiet zones (i.e. blank space before and after a bar code) -Correct number and format of characters

Decoder - As part of a bar code reading system, the electronic package that receives the signals from the scanner, performs the algorithm to interpret the signals into meaningful data, and provides the interface to other devices.

Defects - Defects are voids found in the bars or spots found in the spaces and quiet zones of a bar code symbol. Defects are measured by the ratio between the maximum element reflectance nonuniformity and symbol contrast. Element reflectance nonuniformity is the difference in reflectance between the highest peak and lowest value within an element (bar or space) of the bar code symbol. When an element consists of a single peak or valley, its reflectance nonuniformity is zero. Defects = ERNmax/SC. The grade for Defects is determined by: A(4.0)<=.15 B(3.0)<=.20 C(2.0)<=.25 D(1.0)<=.30 F(0)>.30.

Density - See Character Density.

Depth of Field - The distance between the maximum and minimum plane in which a code reader is capable of reading symbols of a specified X dimension.

Diffuse Reflection - The component of reflected light that emanates in all directions from the reflecting surface.

Direct Thermal - A process in which a set of pins on a printhead are selectively heated onto heat-sensitive paper (or label stock). In turn, the paper turns dark and a bar code is formed. Over time, a Direct Thermal image will eventually fade. Also known as Thermal Printing.

Discrete Code - A bar code symbology where the spaces between characters (interchanger gap) are not part of the code, e.g., Code 39.

DPI - Dots Per Inch.

EAN - European Article Numbering system, the international standard bar code for retail food packages.

Edge Contrast Minimum (Ecmin) - The Edge Contrast Minimum is the minimum difference in the reflectance value between any particular space (including quiet zones) and its adjoining bar within a bar code symbol. The smallest difference that is found across a bar code symbol must be at least 15%.

Edge Determination - In order to calculate the grade of Edge Determination, the Global Threshold (GT) of the bar code must first be determine: GT = Rmin + (SC/2). Once the Global Threshold is established, the elements of a bar code are defined as: BAR: Any point on the SRP at or below the Global Threshold. SPACE: Any point on the SRP above the Global Threshold. If the number of elements for a bar code symbology are invalid, the symbol will receive an "F"grade for Edge Determination.

Element - In a bar code symbol, a single bar or space.

FCC - Federal Communication Commission.

FFO - Fixed Focus Optics technology uses a small aperture and non-moving lenses to digitize an image over a wider range of distance than the traditional CCD reader.

Film Master - A photographic film representation of a specific bar code or OCR symbol from which a printing plate is produces.

First Read Rate - The ratio of the number of successful reads on the first scanning attempt to the number of attempts. Commonly expressed as a percentage. Abbreviated as FRR.

Font - A specific size and style of printer's type.

Font-Independent OCR - Optical character recognition by generalized algorithms allowing wide ranges of character fonts. In the most general case, this extends to bar code patterns as well.

Global Threshold - See definition of GT.

GT - Abbreviation for Global Threshold. The global threshold is a position located half way between the highest recorded reflectance and the lowest recorded reflectance on a scan reflectance profile.

Guard Bars - The bars that are at both ends and center of a UPC and EAN symbol. They provide reference points for scanning, serving a function similar to start/stop codes.

GUI - Graphical User Interface. The visual design of a software application.

Height - This number indicates how many horizontal scan lines of the video camera detected bar code data. It is figured out by determining the difference between the lowest scan line number ever decoded and the highest scan line ever decoded. A standard UPC label will have a height of 140. This figure can be found on the SETUP SCREEN.

Helium Neon Laser - A type of laser commonly used in bar code scanners. It emits coherent red light in a wavelength of 633 nanometers.

Horizontal Bar Code - A bar code or symbol presented in such a manner that its overall length dimension is parallel to the horizon. The bars are presented in an array which look like a picket fence.

I - 25 - See Interleaved 2 of 5.

IAN - Industrial Article Numbering. See EAN.

Ideal - It is a number which indicates the ideal IRIS setting in a camera based reader.

In Spec - A term used to describe a bar code symbol that has been printed in complete compliance with the symbology specification's requirements for element widths and tolerances, element reflectivity and uniformity, spots, voids, and edge roughness.

Infrared Laser Diode - An invisible light beam used in some bar code readers to scan a bar code that is invisible to the human eye. This technology is used specifically to prohibit people from visually reading the bar code. Analogous to night vision goggles.

Input Device - That portion of a bar code reading system that employs electro-optical techniques to determine the localized reflectivity of a symbol.

Intercharacter Gap - The space between two adjacent bar code characters in a discrete code. For example, the space between two characters in Code 39.

Interleaved 2 of 5 - A numeric only bar code consisting of five bars. Two bars are wide, three are narrow. Used generally in industrial and master carton labeling.

Interleaved Bar Code - A bar code in which characters are paired together using bars to represent the first character and spaces to represent the second, i.e., Interleaved 2 of 5 (See Continuous Code).

Iris - [Vmax - Vmin = Iris] This number is an indication of how much light is being allowed on to the surface of the CCD element of the video camera. It is always equal to Vmax minus Vmin. It can be found on the SETUP SCREEN.

Iso - The international standards organization,k and international nongovernmental organization responsible for the development of voluntary standards.

Label Repeat - The distance between the top of a bar code image to the top of the next bar code image.

Ladder Barcode - See Vertical Bar Code.

Laser Scanner - An optical bar code reading device using a low energy laser light beam as is source of illumination.

LCD - Liquid Crystal Display.

LED - Light emitting diode. A semiconductor that produces light at a wavelength determined by its chemical composition. The light source often used in light pens.

Light Pen - In a bar code system, a hand-held scanning wand that is used as a contact bar code reader held in the hand. (See Wand Scanner.)

LPM - Lines per minute.

MaxiCode - Fixed size two dimensional symbology having elements arranged around a unique circular finder pattern. MaxiCode is omnidirectional and is primarily used for freight sortation and tracking.

MICR - Magnetic Ink Character Recognition style printing on the bottom of personal and bank checks.

Mil - One one-thousandth of an inch (0.001"). Bar code densities are commonly referred to as number of mils (i.e. 10 mils).

Minimum Reflectance (Rmin) - The reflectance value of the darkest bar within a bar code symbol must be less than or equal to half the reflectance of the lightest space.

Misread - A condition that occurs when the data output of a reader does not agree with the data encoded in the bar code symbol.

Modulation - Modulation relates to how a scanner "sees" wide elements in relationship to narrow elements, as represented by reflectance values in the Scan Reflectance Profile. Scanners typically "see" narrow spaces as being less reflective than wide spaces. The closer the grades of Edge Contrast Minimum and Symbol Contrast, the higher the Modulation grade. MOD = ECmin/SC. The grade for Modulation is determined by: A(4.0)>=.70 B(3.0)>=.60 C(2.0)>=.50 D(1.0)>=.40 F(0)<.40

Module - The narrowest nominal width unit of measure in a bar code.

Modulo Check Digit or Character - See Check Character.

Moving Beam Bar Code Reader - A scanning device where scanning motion is achieved by mechanically or electronically moving the optical geometry.

MRD - Minimum Reflectance Differential. A method that is used to determine if there is an adequate difference between absorbed and reflected light.

MSI Plessey - Modified Plessey Code is a pulse width modulated bar code used primarily for making retail shelving.

N - The ratio between the widths of wide elements and narrow elements in a 2-width symbology.

Nanometer - A unit of measure used to define the wavelength of light. Equal to 10-9 meters.

Narrow bar - 1. An indication of the bar width in nanoseconds. 2. This generally refers to the narrowest bar in a bar code.

Nominal - The exact (or ideal) intended value for a specified parameter. Tolerances are specified as positive and negative deviations from this value.

Non-Read - In a bar code system, the absence of data at the scanner output after an attempted scan due to no code, defective code, scanner failure or operator error.

Numeric - A character set that includes only the numbers.

OCR - Optical Character Recognition is a technology designed specifically to read certain stylized fonts (such as OCR-A and OCR-B) containing the full alphanumeric character set. The term OCR is also used when translating and inputting other stylized fonts (such as Courier) or text found in magazines and newspapers into a computer. This technology is also referred to as Intelligent Character Recognition (ICR).

OCR - A - An abbreviation commonly applied to the character set contained in ANSI Standard X3.17-1981.

OCR - B - An abbreviation commonly applied to the character set contained in ANSI Standard X3.49-1975.

Omnidirectional - A scanner that can read in both horizontal and vertical label positions, or any position between horizonal and vertical.

Omnidirectional Label - Two oversquare bar codes, placed perpendicular to each other. A common application is the airline baggage label.

Opacity - The optical property of a substrate material that quantifies the show-through from the back side or the next sheet. The ratio of the reflectance with a black backing to the reflectance with a white backing. Ink opacity is the property of an ink that prevents the substrate from showing through.

Optical throw - The region between the scanner and the readable depth of field.

Orientation - The alignment of a bar code symbol with respect to horizontal. Two possible orientations are horizontal with vertical bars and spaces (picket fence) and vertical with horizontal bars and spaces (ladder).

Overhead - Overhead - In a bar code system, the fixed number of characters required for start, stop and checking in a given symbol. For example, a symbol requiring a start/stop and 2 check characters contains 4 characters of overhead. Thus to encode 3 characters, 7 characters are required to be printed.

Oversquare - A label in which the height is greater than the length.

PCS - Print Contrast Signal. A measurement of the ratio of the reflectivities between the bars and spaces of a symbol, commonly expressed in percent. PCS is calculated as: RL-RD/RL x 100%, where RL = reflectivity of the light elements and RD = reflectivity of the dark elements.

PDF417 - Two-dimensional bar code providing error correction, detection and security used primarily in parcel tracking applications and hazardous material control.

PDT - Portable Data Terminal. Handheld terminal capable of storing and recording data that is captured remotely and later transmitted into a computer.

Picket Fence Code - See Horizontal Bar Code.

Pitch - Rotation of a bar code symbol about an axis parallel to the direction of the bars.

PostNet - Postal Numeric Encoding Technique used to encode ZIP code information on letter mail. PostNet uses redundant information within a compact bar code format to provide error detection capability and a significant degree of error correction capability.

Print Contrast - See PCS.

Print Quality - The measure of compliance of a bar code symbol to the requirements of dimensional tolerance, edge roughness, spots, voids, reflectance, PCS, quiet zone, and encodation.

Printhead - The device on a direct thermal or thermal transfer printer containing the heating element that causes that image to be transferred to the facestock.

Quiet Zone - A clear space, containing no dark marks, that precedes the start character of a bar code symbol and follows the stop characters. Sometimes called the "clear area".

Raster - More than one scan line in two or more horizontal dimensions to allow reading of bar codes in different positions.
Ratio The ratio between wide elements and narrow elements. It is used to measure decodability properly. This applies to symbologies such as Code 39 Codabar and, 2 of 5.

Read window - The region within which the scanner is capable of reading bar code. The read window is defined by the scanner's scan width, focal point, and depth of field.

Reader - See Bar Code Reader.

Reduced Scale Symbology - See RSS.

Reflectance - The ratio of the amount of light of a specified wavelength or series of wavelengths reflected from a test surface to the amount of light reflected from a Barium Oxide or Magnesium Oxide standard under similar illumination conditions.

Resolution - In a bar code system, the narrowest element dimension that can be distinguished by a particular reading device or printed with a particular device or method.

RF - Radio Frequency. Wireless communication technology using electromagnetic waves to transmit and receive data. RF provides real-time access to a host computer.

Ribbon - Material used with thermal transfer printers producing visible marks on a label (or substrate). A printhead is heated and the ribbon is burned on the label stock producing the bar code.

RSS-14 - Encodes the full 14 digit EAN.UCC item identification in a linear symbol.

RS-232 - The most common communication interface (e.g. serial (COM) port) standard using a DTE (Data Terminal Equipment) and DCE (Data Communications Equipment) interface. Also known as serial communication.

RS-422 - The second most common communication interface standard which extends beyond the 100 feet limitation of RS-232 data communication supporting a maximum distance of 4000 feet.

RSS - A bar code symbology that contains three linear symbologies to be used with the EAN.UCC system. The use of the symbologies are restricted and subject to compliance with the EAN International (EAN) and Uniform Code Council Inc (UCC) rules and registration procedure.

RSS Expanded - Encodes EAN.UCC item identification plus supplementary AI element strings such as weight and "best before" date in a linear symbology. RSS expanded can also be pinted in multiple rows as a stacked symbol.

RSS Limited - Encodes the 14-digit EAN.UCC item identification with indicator digits of zero or one in a linear symbol for use on small items.

RSS Stacked - A version of the RSS-14 symbology that is stacked in two rows and is used when the normal symbol would be too wide for the application. It comes in two versions, a truncated version used for small item marking applications and a taller omnidirectional version which is designed to be read by omnidirectional scanners. RSS expanded can also be pinted in multiple rows as a stacked symbol.

Scan line - The beam of light that reads across the bar code for information.

Scan rate - Scanner speed, in scans per second.

Scan Reflectance Profile (SRP) - A map (or plot) of the localized symbol reflectivity as a measuring aperture is scanned across the symbol along a specific path. The "peaks" of the SRP indicate the largest value of reflectance (the spaces in the bar code) and the "valleys" of the SRP indicate the smallest value of reflectance (the bars in the bar code).

Scanner - An electronic device that electro-optically converts optical information into electrical signals.

Self-Checking - A symbology is termed self-checking if a single printing defect will not cause a character to be transposed into another valid character in the same symbology.

Serial Communication - See RS-232.

Skew - Rotation of a bar code symbol about an axis parallel to the symbols length.

Skew - The rotation of a bar code symbol about an axis parallel to the bars.

Space - The lighter element of a bar code usually formed by the background between bars.

Space Width - The thickness of a space measured from the edge closest to the symbol start character to the trailing edge of the same space.

Spectral Response - The variation in sensitivity of a reading device or the variation in reflectivity of a test surface to light of different wavelengths.

Specular Reflection - The mirror-like reflection of light from a surface.

Specular reflection zone - A narrow zone in front of the scanner in which direct, non-diffused light blinds the scanner.

Spot - 1. The undesirable presence of ink or dirt in a space. 2. The area on a bar code symbol that is being examined by an input device at any given point of time.

SRP - See scan reflectance profile.

Stack Code - Two-dimensional bar code where linear bar codes are stacked one upon another and are printed in a rectangular shape to achieve the most efficient use of label area.

Standard - A set of rules, specifications, instructions, or directions for printing, labeling, scanning, etc. bar coded information.

Start/Stop Character or Pattern - A special bar code character that provides the scanner with start and stop reading instructions as well as scanning direction indicator. The start character is normally at the left-hand end of a horizontally oriented symbol. The stop character is normally at the right-hand end of a horizontally oriented symbol.

Substitution Error Rate (SER) - The rate of occurrence of incorrect characters from an automatic identification system.

Substrate - The surface on which a bar code symbol is printed.

Symbol - A combination of bar code characters including start/stop characters, quiet zones, data characters, and check characters required by a particular symbology, that forms a complete, scannable entity.

Symbol Contrast: (SC) - The difference between the largest (including quiet zones) and smallest reflectance values within a Scan Reflectance Profile. SC = R,ax - Rmin. The grade for Symbol Contrast is determined by: A (4.0)>=70% B (3.0)>=55% C(2.0)>=40% D(1.0)>=20% F(0)<20%

Symbol Density - See Bar Code Density.

Symbol Length - The distance between the outside edges of the quiet zones on the two ends of a bar code symbol.

Target - This number correlates vision based bar code data to wand bar code data. A target value will increase or decrease due to differences in X dimensions, bar heights, or electronic noise. A full size UPC label will have a target of 190.

Thermal - See Direct Thermal.

Thermal Transfer - A process in which a set of pins on a printhead are selectively heated onto a ribbon and the ink from the ribbon is burned (transferred) onto the label stock. Thermal transfer leaves a permanent image on the label.

Tilt - Rotation of a bar code symbol about an axis perpendicular to the substrate.

Traditional OCR - The first form of 2-dimensional OCR developed, using the stylized OCR-A and OCR-B fonts.

Trigger - A method for informing the scanner/decoder of when to look for bar codes. This can be an external sensor device or a host-generated signal.

UCC - Uniform Code Council is an organization which administers the UPC and other retail standards.

UCS - Uniform Container Symbol.

Uniform Code Council (UCC) - Previously the Uniform Product Code Council, the organization that administers the UPC and other retail standards.

UPC - Universal Product Code, the standard bar code symbol for retail food packages in the United States.

UPC-A - A UPC symbol encoding a number system character, 10 digits of data, and a check digit.

UPC-E - A UPC symbol encoding 6 digits of data in an arrangement that occupies less area than a UPC-A symbol. Also called a "zero-suppressed" symbol because a 10
digit UPC-A code can be compressed to a 6 digit UPC-E format by suppressing redundant zeros.

USS - Uniform Symbol Specification. The current series of symbology specifications published by AIM; currently include USS-Interleaved 2 of 5, USS-39, USS-93, USS-Codabar, and USS-128.

Verifier - A device which measures the characteristics of a bar code including the contrast, reflectance, modulation, and compliance with the parameters of the bar code symbology to ANSI/ISO standards.

Vertical Bar Code - A code pattern presented in such orientation that the axis of the symbol from start to stop is perpendicular to the horizon. The individual bars are in an array appearing as rungs of a ladder.

Visible Laser Diode - Used in most handheld scanners to project a visible red light for scanning human readable bar codes.

Vmax - This number indicates a value for the highest point of reflectivity in the image of a bar code as used in camera based systems.

Vmin - This number indicates a value for the lowest point of reflectivity in the image of a bar code label as used in camera based systems.

Void - The undesirable absence of ink in a printed bar.

Wand - See Wand Scanner.

Wand Scanner - A handheld scanning device used as a contact bar code or OCR reader.

Wedge - A hardware device or software program (Software Wedge) which uses a scanner for input and sends data directly into an application by emulating a keyboard stroke. A wedge (hardware wedge) is an external device and plugs between the keyboard and terminal.

WYSIWYG - "What You See Is What You Get" is a term used to describe the presentation of the printable output viewed as is on the terminal.

X Dimension - The nominal width dimension of the narrow bars and spaces in a bar code symbol. The narrowest element of a barcode image.

X Dimension - The dimension of the narrowest bar in a bar code.

Z Dimension - The achieved width of the narrow elements, calculated as the average of the average narrow bar width and the average narrow space width.