The application of bar code technology has been recognized and accepted by more and more people, especially the application of bar code technology in commodity circulation management has achieved very gratifying results. The popularity of barcodes for food, beverages, daily chemical products and other commodities is also increasing. Because of this, the application of barcode technology in commodity circulation management has been promoted, and more and more shopping malls, specialty stores, etc. are using barcode technology in part or in all aspects to manage commodities.

1. Barcode application in retail industry

1. Related terms and definitions

1) Product barcode

2) Retail merchandise

3) Retail commodity code

4) Prefix code

5) Magnification factor. The ratio of the actual size of the barcode to the size of the barcode with a module width (X dimension) of 0.330mm.

2. The principles of code preparation

1) The principle of uniqueness

2) The principle of meaninglessness

3) The principle of stability

3. Compilation of retail commodity codes

1) Compilation of individual retail commodity codes in individual packages

Individually packaged individual retail items are individual, non-divisible individually packaged retail items. The compilation of its commodity code usually adopts the specified 13-bit code structure. When the package of the product is small, the specified 8-bit code structure can be applied for.

2) Compilation of retail commodity codes for combined packaging

(1) Compilation of retail commodity codes for standard combination packaging.

A retail commodity in a standard combination package is a commodity in a standard, stable combination package consisting of multiple identical individual commodities. The compilation of its commodity code usually adopts a 13-digit code structure, but it should not be the same as the code of the single commodity contained in the package.

(2) Compilation of retail commodity codes for mixed and combined packaging.

A mixed packaged retail product is a standard, stable packaged product that consists of a number of different individual products. The compilation of its commodity code usually adopts a 13-digit code structure, but it should not be the same as the code of the commodity contained in the package.

3) Compilation of variable retail commodity codes

Variable retail item codes are used for item consumption units inside a store or in a closed system.

4. Barcode representation of retail products

The barcode representation of retail commodity codes uses the EAN/UPC barcode symbology as defined in ISO/IEC 15420. EAN/UPC barcodes have four structures: EAN-13, EAN-8, UPC-A, and UPC-E.

1) The 13-bit coded barcode adopts EAN-13 barcode symbol.

2) The 8-bit encoded barcode adopts EAN-8 barcode symbol.

3) The 12-bit coded barcode adopts UPC-A barcode symbol.

4) 13-digit code and EAN-13 barcode

The code structure is a 13-digit code composed of three parts: manufacturer identification code, commodity item code, and check code. It is divided into 4 structures.

(1) Manufacturer identification code

The manufacturer identification code consists of 7 to 10 digits, and the China Article Numbering Center is responsible for distribution and management. The first three codes of the manufacturer's identification code are the prefix codes, and the prefix codes assigned by the International Article Numbering Association to the China Article Numbering Center are 690-695.

(2) Commodity item code

The commodity item code consists of 2 to 5 digits, which is generally compiled by the manufacturer, and can also be compiled by the China Article Code Center.

(3) Check code. The check code is a 1-digit number, which is used to verify the correctness of the entire code

The 8-digit code and EAN-8 barcode code structure consists of three parts: prefix code, commodity item code and check code.

(1) Prefix code

X8~X6 are prefix codes, which are 690~695 assigned by the International Article Numbering Association to the China Article Numbering Center.

(2) Commodity item code

X5~X2 is the commodity item code, which consists of 4 digits, and the China Item Coding Center is responsible for distribution and management.

(3) Check code

X1 is the check code, which is a 1-digit number, which is used to check the correctness of the entire encoding.

3) 12-digit code and UPC-A barcode Code structure: composed of 12-digit numbers representing manufacturer identification code, commodity item code and check code

(1) The manufacturer identification code is the code assigned to the manufacturer by the Uniform Code Committee (GS1 US) and consists of 6 to 10 digits from the left.

(2) The commodity item code consists of 1 to 5 digits of the manufacturer's code.

(3) The check code is 1 digit, and the calculation method is the same as EAN-13.

(4) The zero-elimination compression code structure is obtained by compressing the 12-bit code whose system character is 0.

8-digit X8X7X6X5X4X3X2X1) code.

Basic Concept

1. bar code in-store

Commodity barcodes with a prefix of 20 to 24 are used to identify the commodities and variable retail commodities that are processed by the store and sold in the store.

8-digit in-store barcodes have a prefix of 2.

2. variable measure retail commodity

In the retail trade process, the sales unit cannot be determined in advance, and the commodity is priced and sold according to the basic measurement unit.

3. Coding in special cases

Coding of product variants

"Product Variation" means any change made to the Product by the manufacturer during the life of the Product. The product is only subject to minor changes or improvements and does not need to be assigned a different product identification code. When a product change affects the product's weight, size, packaging type, product name, trademark, or product description, a separate product identification code must be assigned.

Coding of Combination Packages

If the commodity is a stable unit of combination, each part has its corresponding commodity identification code. Once the commodity identification code of any combination unit is changed, or the combination of the combination unit is changed, a new commodity identification must be assigned. If the combined unit changes slightly, its commodity identification code generally remains unchanged, but if the commodity needs to be effectively ordered, marketed or tracked, it must be classified and identified, and the commodity identification code must be assigned separately. A new variant of a product replaces the original product, and consumers have seen from the change that the two are completely different. At this time, the new product must be assigned a commodity identification code that is different from the original product.

The code of the promotional item

A "Promotional Item" is a temporary change in the product and a noticeable change in the appearance of the product. This change is determined by the supplier, and the end user of the commodity benefits from it. Often the promotional variant and its standard product coexist in the market. Promotional variants of a product that affect the size or weight of the product must be assigned a different, unique product identifier. Promotional items that are clearly marked with a reduced price on the packaging must be assigned a unique product identification code. For example, the packaging says "Save $2.50". A unique product identification code should be assigned separately for seasonal promotional items. For example, the candy packaging that is only available during the Spring Festival.

Reactivation of product identifiers

Manufacturers should consider the following two factors when re-enabling product identifiers:

1) Reasonably predict the duration of the circulation of goods in the supply chain

According to the EAN·UCC specification, according to international practice, generally speaking, products that are no longer produced cannot be redistributed to other commodity items for at least 4 years from the date when the manufacturer sends the last batch of commodities. For clothing items, the minimum period may be 2 1/2 years.

2) Reasonably predict the preservation period of commodity historical data

Even if the commodity is no longer circulated in the supply chain, it is necessary to keep its commodity identification code in the database for a longer period of time to preserve historical data. Therefore, this factor needs to be considered when reactivating the commodity identification code.

Fourth, the selection of barcode reading equipment in the POS system

Barcode reading equipment can be divided into contact and non-contact barcode scanners in terms of scanning methods. Contact reading equipment includes light pen and card slot barcode scanner; non-contact reading equipment includes CCD scanner and laser scanner.

Barcode reading equipment can be divided into two types of barcode scanners: handheld and fixed.

According to the ability to read the code system, barcode scanning equipment can be divided into four types of barcode scanners: light pen, CCD, laser and photographing in principle.

Light pen and card slot barcode scanners can only read 1D barcodes.

Laser barcode scanners can only read row-type two-dimensional codes (such as PDF417 codes) and one-dimensional codes.

The image barcode reader can read common one-dimensional barcodes, and can also read row-type and matrix-type two-dimensional barcodes.

Graphic acquisition and digital processing There are two main ways to acquire barcode graphics, namely "optical imaging" (Image) and "laser" (Laser). Among them, there are two kinds of optical imaging methods, one is area array CCD and the other is CMOS.

Two parameters for choosing a CCD scanner

(1) Depth of field. Since the imaging principle of the CCD is similar to that of a camera, if the depth of field is to be increased, the lens should be enlarged accordingly, so that the CCD is too bulky and inconvenient to operate. An excellent CCD should be able to read without sticking to the bar code, and should be moderate in size and comfortable to operate.

(2) Resolution. If you want to increase the CCD resolution, you must increase the unit element of the photosensitive element at the imaging location. Low-cost CCD is generally 512 pixels (pixel), which is enough to read EAN, UPC and other commodity barcodes, but it will be more difficult to read other code systems. The mid-range CCD has as many as 1024 pixels, and some even reach 2048 pixels, which can distinguish the barcode with the narrowest unit element of 0.1mm.