Code 128

The word “ Wikipedia ” written with Code 128-B

The Code 128 barcode standard is significantly different from common bar code standards such as, for example, EAN . The differences lie primarily in the possibility of coding not only numbers, but also letters of the Latin alphabet, as well as special characters. In addition, the digital code in the Code 128 format becomes very compact, which is achieved due to the “double packing” of data when two digits are written into one barcode template. Letter characters are encoded in the usual “single” way, which makes a literal code in Code 128 format twice as long as a digital one.

Content

Description

The Code 128 bar code includes 107 characters, of which 103 are data symbols, 3 start and 1 stop (stop) symbol. To encode all 128 ASCII characters , three sets of Code 128 bar code symbols are provided - A, B, and C, which can be used within a single barcode.

128A - characters in ASCII format from 00 to 95 (numbers from “0” to “9” and letters from “A” to “Z”), special characters and FNC characters 1-4;
128B - ASCII characters from 32 to 127 (numbers from “0” to “9”, letters from “A” to “Z” and from “a” to “z”), special characters and FNC symbols 1-4;
128C - numbers from 00 to 99 (two-digit number is encoded by one character) and the symbol FNC 1.

Technical requirements for Code 128 bar code symbology, symbology indicators, data character encoding, sizes, decoding algorithms, application parameters and prefix strings and symbology identifier in Russia are regulated by GOST 30743-2001 (ISO / IEC 15417-2000) (Replaced by GOST ISO / IEC 15417-2013) “Automatic identification. Bar coding. Code 128 Symbology Specification (Code 128). ”

Code 128 Structure

The structure of the Code 128 barcode is quite simple. The barcode consists of six zones:

White field;
Start character (Start);
Coded information;
Verification symbol (check mark);
Stop symbol;
White field.

Code 128 bar code symbols consist of three bars and three spaces. Strokes and spaces are modular in construction. The width of each bar and the gap is from 1 to 4 modules (1 module = 0.33 mm). The width of the character is 11 modules. The stop (stop) sign consists of thirteen modules and has four strokes and three spaces.

Code 128 Mark

There are 107 patterns (patterns), each of which is encoded by 11 modules, including 3 bars (slim bars) and 3 gaps (spaces). The exception is that the stop pattern [STOP] has 4 strips and is encoded by 13 modules.

Each pattern is decoded according to the table; for some patterns, control actions are defined that determine the decoding mode.

One of the three start patterns [START-A] (# 103), [START-B] (# 104) or [START-C] (# 105) restricts the code on the left and defines the decoding table (A, B or C). The [STOP] pattern (# 106) restricts the code to the right. Before the [STOP] pattern comes a checksum pattern. To the left and right of the barcode there must be a free space (Quiet zone) of at least 10 modules wide.

The [SHIFT] template (# 98 in Tables A and B) allows you to switch between Tables A and B. The templates [Code C] (# 99 in Tables A and B), [Code B] (# 100 in Tables A and C) and [Code A] (# 101 in Tables B and C) control the direct inclusion of the corresponding decoding table.

Functional patterns [FNC1] - [FNC4] are not defined.

The checksum occupies one pattern and must be added before the [STOP] pattern. The steps for calculating the check digit are as follows:

1. Initial value = pattern value [START] (103, 104, or 105).

2. For each next pattern in the message (excluding [STOP]): take its value, multiply it by its position (the position of the first pattern after [START] is 1). Add the result to the checksum.

3. The remainder of dividing the result by 103 will be considered a checksum.

The value (value) of a template is its ordinal number in the table (counting from zero). ^[one]

Notes

↑ TradePilot (Russian) . - Description of the Standard Code 128 barcode standard. Appeal date November 29, 2009. Archived April 13, 2012.

Online barcode generator A free online resource for generating CCs of various types.