Code 128 is a high-density barcode symbology that accepts a full 128 ASCII character set, the extended ASCII character set, and four non-data function characters.
Code 128 is popular worldwide because of its ability to store a large amount of data in a small space. It is the preferred barcode for many standards, including GS1-128, EAN-128, GTIN, UCC-128, ISBT-128, SISAC, SICI, ICCBBA, EAN-14, SSCC-18 and SCC-14.
Code 128 allows numeric data to be represented in a compact double-density mode, with two data digits for every symbol character. Each character is made up of three bars and three spaces for a total width of 11 modules. Each bar or space may consist of one to four modules.
Code 128 has three different character code subsets: A, B, and C. You can either pick the subset you would like, or have the software automatically select the subset that creates the smallest possible Code 128 bar code.
The valid characters for each of the code subsets are outlined in the following table:
|
SUBSET |
Description |
|---|---|
|
A |
All of the standard upper-case alphanumeric keyboard characters together with the ASCII control characters (i.e. ASCII character values 0-95) and four special function codes (FNC 1-FNC 4). |
|
B |
All of the standard upper-case alphanumeric keyboard characters together with lower-case alphabetic characters (i.e. ASCII character values 32-127) and four special function codes (FNC 1-FNC 4). |
|
C |
Numeric data (0-9) and one special function code (FNC 1). If you force subset C, Tattoo ID ensures that all numeric data entered is an even number of digits by inserting a leading zero as needed. |
Code 128 provides four special non-data function codes: FNC 1 through FNC 4. These codes have a variety of functions to extend the capabilities of Code 128:
FNC 1 defines the data to be in UCC/EAN 128 symbol coding format.
FNC 2 tells the bar code reader to store the data and transmit it with the next symbol.
FNC 3 initializes the bar code reader.
FNC 4 indicates special functions are to be defined.
In general, Code 128 bar code specifications are as follows:
|
Specifications |
Description |
|---|---|
|
Character set: |
Entire 128 ASCII character set |
|
Length: Height: |
Variable NOTE: Code128 is comprised ofs a combination of 6 bars and spaces for each character except the Stop character, which uses 7. Each character starts with a bar and ends with a space except the stop character, which ends in a bar. |
|
Data character density: |
9.1 characters per inch or 18.2 numeric-only characters per inch Based on X = 0.010 inch (0.25 mm) |
|
Check Digit: |
One that is mandatory (Modulo 103) |
|
Quiet zone: |
Equivalent to 3.18 alphanumeric characters |
|
Composition: |
Quiet zone | Start code | Data | Check digit | Stop character | Quiet zone |
|
Options: |
Four non-data function codes: FNC 1, FNC 2, FNC 3, and FNC 4. |
GS1-128
The GS1-128 barcode standard (previously referred to as UCC/EAN-128 or EAN-128) adds security to your supply chain by encoding data such as, Best Before Date, Batch/Lot Number, Serial Number and GS1 System’s Serial Shipping Container Code (SSCC). The code has the following composition:
Code 128 start character (START-A, START-B or START-C)
Code 128 FNC1 character
Application Identifier (AI) - Defines the type of encoded data that follows
Encoded Data
Symbol Check character
Stop Character
In addition, it has a 48 Alphanumeric capacity and is not Omnidirectional.