IBM 4400 manual Modulo-103 Check Digit

Chapter 7 Bar Codes

Data Field

UCC/EAN-128 bar codes require a special character called “Function 1” (FNC1) to immediately follow the start code. ASCII Emulation automatically supplies this character, so it must not be included in the data field by the user.

A character is made up of three bars and three spaces, each varying in width from 1 through 4 modules, for a total of eleven modules. The number of modules making up the bars is even. The stop code has four bars and is 13 modules wide.

The character set for UCC/EAN-128 is the same as the character set for Code

128.See the Code 128 Character Set (Table 68 on page 231). Every character is interpreted according to the currently active character subset. UCC/EAN-128 uses subset B and subset C only. Subset B, shown in Table

69on page 232, includes all standard alphanumeric keyboard characters, lowercase alphabetical characters, and special characters. Subset C interprets the characters as pairs of numbers 00 through 99, along with some special characters, as shown in Table 70 on page 233. The start code or subset switch code determines whether a particular bar code character is decoded as one character or as a pair of numbers.

Readable Data

The optional printed data field (PDF) provides a human-readable interpretation of the bar code data. When the printed data field is enabled by use of the “PDF” parameter, the overall height of the bars is reduced to make room for a guard band and the human-readable characters. The printed data field will be formatted with spaces or parentheses denoting particular data fields such as the application identifier. Special characters such as start, stop, subset switch, modulo-103 check digit, and FNC1 do not appear in the human-readable data.

The readable data is oriented along the bar code from start code to stop code. It may be positioned above or below a bar code.

Modulo-103 Check Digit

A modulo-103 check digit is automatically calculated and inserted in the bar code symbol immediately in front of the stop code, in the same manner as the Code 128 bar code. The check digit verifies accurate scanning. The start code is included in the check digit algorithm. The modulo-103 check digit is not displayed in the readable data field.

Modulo-10 Data Field Check Digit for SSCC-18 and SCC-14

AI 00 (called the Serial Shipping Container Code, or SSCC-18) takes 18 additional numerical data bytes. The last data byte is a mod-10 check digit on the preceding seventeen data bytes. Counting the two zeros of the application identifier, the mod-10 check digit is the twentieth byte in the data field.

AI 01 (called the Shipping Container Code, or SCC-14) takes 14 additional numerical data bytes. The last data byte is a mod-10 check digit on the preceding 13 data bytes. Counting the zero and the one of the application identifier, the mod-10 check digit is the sixteenth byte in the data field.

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