00193891-0702_AI_LP_Barcode_DE+EN.pdf - 第219页

SIPLACE 2 PCB barcode scanner assembly instructions 10/2009 Edition 2.11 PCB barcode scanner configuration 219 Disadvant ages: - th e print quality o f a barcode on th e labels is a d ecisive factor in the scanning resul…

2 PCB barcode scanner assembly instructions SIPLACE

2.11 PCB barcode scanner configuration 10/2009 Edition

218

2.11 PCB barcode scanner configuration

2.11.1 General notes about the barcode

Today, increasing numbers of components, individual components, semi-finished and end prod-

ucts are being uniquely identifed with a barcode, whic

h makes them easier to check. This, in turn,

makes it easier to control production, stock-keep and to trace components in the event of errors.

Both one-dimensional (1D, e.g. barcodes) and two-dimensional (2D, e.g. data matrix codes)

codes can be used.

2.11.2 Structure of 1D barcodes

Barcode types include 2/5 interleaved, Codabar, Code 39, Code 128, EAN 8, EAN 13 for industrial

applications.

The 1D barcode scanner reads the barcode using a red light laser diode and a rotating mirror

whee

l, which creates a red scanning line that is visible to the human eye.

The structure of a barcode, the nu

mber of black lines and white gaps for each character to be

coded is fixed for each barcode type. The information is located in both the lines and the gaps of

a barcode but, in general, the following structure can be defined for a barcode.

Fig. 2.11 - 1 Structure of a 1D barcode

Advantages: - up to 50 characters can be encoded, depending on the type of code.

- barcodes can be read and scanned very re

liably with the optical scanning system

- barcodes are cheap to produce

- barcode scanners are very cheap to buy

SIPLACE 2 PCB barcode scanner assembly instructions

10/2009 Edition 2.11 PCB barcode scanner configuration

219

Disadvantages: - the print quality of a barcode on the labels is a decisive factor in the scanning

result.

2.11.3 Structure of 2D barcodes

Barcode types: 2

1. "Stacked" codes. These are essentially one-dimensional barcodes that are printed directly over

one another. Typical stacked barcodes include the PDF 417, RSS-14 Stacked and the 16K.

Fig. 2.11 - 2 Stacked barcodes

2. 2D barcodes, known as "matrix codes“ are another variant of the 2D barcodes. Again there are

various types commonly used, such as Aztec code, Maxi code, Code One and the data matrix

code.

Fig. 2.11 - 3 2D barcodes

Data matrix code: The data matrix code consists of 4 main components. 2

1. The fixed dividing line ('corner’). This fixed dividing line

is used for pattern recognition and to calculate the rotary

position of the data matrix code.

2. The non-closed border (opposite corner). This

open corner is used to identify the number of lines and gaps.

This is known as the "matrix density“.

On the ECC 200, the

element in the top right-hand corner is white.

3. The storage area. This contains th

e binary information in coded

form. Depending on the cell size, it also defines the number of possible

items of information.

2 PCB barcode scanner assembly instructions SIPLACE

2.11 PCB barcode scanner configuration 10/2009 Edition

220

4. The 'rest zone'. This empty zone surrounds the data matrix code.

It contains no information and is no

t used for orientation.

The width of the rest zone is one field or one line.

The 2D barcode scanner can read both 1D and 2D barcodes.

They can be detected using a CCD chip.

Advantages of data matrix code:

– Flexible in terms of the range of applications

– Very high information density in the smallest space (over 2000 characters)

– Scanning is possible from any angle

– Minimal requirements in terms of c

lor contrast and print quality and thus suitable for direct la-

belers (e.g. laser labelers or needle embossing) as these requ

ire less contrast than for bar-

codes.

– Error correction using the "Reed-Solomon" algorithm - up to 25 % of the code may be dam-

aged.

Sample applications:

– Scanning permanent direct labels (e.g. on tools, motor components, drive parts, surgical in-

struments, etc).

– Production / manufacturing (identification of electro

ic components, tools, etc.)

– Chemical and biomedical analysis instruments

–PCBs

Fig. 2.11 - 4 Data matrix and DOT matrix barcodes

NOTE:

The barcode scanners that we use can read the following barcode types:

1D barcode scanner: Code 39, Code 128, Code 9

3, Codabar, EAN, EAN 128, UPC, 2/5 Inter-

leaved, Pharmacode

2D barcode scanner: Data Matrix ECC200 and 1D ba

rcodes Code 39, Code 128, Codabar, EAN,

EAN 128, UPC, 2/5 Interleaved