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Chapter 7Bar Codes
EAN 8
The EAN 8 bar code structure is shown in Figure 11 and described below.
Figure 11. EAN 8Structure
Quiet Zone
Both ends of the bar code structure have blank quiet zones. The quiet zones
must be at least 0.25 inches wide and completely blank to ensure accurate
reading of the start/stop codes and to prevent adjacent bar codes from
overlapping. You must provide sufficient space on the form for the quiet
zones.
Start/Center/Stop Codes
The start/center/stop codes are special character codes marking those
portions of the bar code. These codes are automatically provided.
Data Field
The bar code symbol uses a series of varying width bars and spaces to
represent a limited character set (numbers 0-9 and Special Characters St art,
Center,and Stop). The bars and spaces vary in width from one throughfour
modules. Each character consists of two bars and two spaces that total seven
modules. The symbol coding of the left data field is different from the r ight
data field to permit read direction sensing.
Readable Data
The human readable data field provides a readable interpretation of the bar
code data. It can either be suppressed or printed above or below the bar code
symbol.
Check Digit
The modulo-10 check digit is automatically calculated and inser ted in the bar
code symbol. The check digit verifies accurate scanning.
QUIET
ZONE
STARTCODE CENTERCODE STOPCODE
LEFTDATA
FIELD RIGHTDATA
FIELD HEIGHT
QUIET
ZONE
OPTIONALREADABLE
SR,SC
POSITION
DATAFIELD
2-or 5-
DIGIT
ADD-ON
CODE
CHECK
DIGIT
FIELD