| What is UPC Version A? |
| How do I calculate the check digit? |
This is easy, lets look at some data. Our
Data 98765432155
All odd numbers are multiplied by 3 and the even number by 1.
Example
| Char. Pos | O | E | O | E | O | E | O | E | O | E | O | Total = 115 |
| Data | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 5 | 5 | Modula 10 of 115 = 120 |
| Multiply | 3 | 1 | 3 | 1 | 3 | 1 | 3 | 1 | 3 | 1 | 3 | |
| Results | 27 | 8 | 21 | 6 | 4 | 9 | 2 | 2 | 3 | 5 | 15 | Check Digit = 5 |
The total minus the Modula 10 value of the total give you the check digit number.
| What is the Layout of the Barcode? |
Below is a simple layout of the barcode.
| Start Character | Left Hand Digits | Center Bar | Right Hand Data | Check Digit | Stop Character |
| 1 Digit | 6 Digits | 1 Digits | 5 Digit | 1 Digits | 1 Digit |
| How do I encode the Barcode? |
Ok, to start with we have a the
first 6 characters which are simply kept as they are, for example 987654
The remaining 5 and the check digits are encoded with parity set C, shown below.
Parity Set C
| Font Character | A | B | C | D | E | F | G | H | I | J |
| Numeric Pos | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
Below is a table giving showing our data encoded as EAN 8.
| Right Data | Left Data | Check Digit | |||||||||||||
| Data | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 1 | 5 | 5 | 8 | ||
| Parity Set | N | O | N | E | C | C | C | C | C | C | C | ||||
| Result | 9 | 8 | 7 | 6 | 5 | 4 | D | C | B | F | F | F | F | ||
| How do I put it all together? |
Simple, we have our final encoded data,
now all we need to do is to add our additional control characters.
Result taken from above 9 8 7 6 5 4 D C B F F F
Start Character is ( or ASCII code 40 Centre Bar Character is - or ASCII code 45
Stop Character is ) or ASCII code 41
Our Final Barcode looks like this (987654-DCBFFF(
To add the digit at the front simply take the first digit from original data, which is
"8". Use the characters from Q-Z for number 0-9, so 8 is Y. The last digit apply
the same technique but using the check digit instead.
Z(987654-DCBFFF(V
You can also use UPC A version with masked first and printable check digit. First digit
after start code is replaced from characters from decimal 161-170, which represent 0-9 for
the Left side data. The readable check digit is replaced with characters from decimal
113-222, which represent 0-9 for the Right side data. So the first digit is "9"
which decimal 200 and the check digit is 5 which is decimal 118.
We have ActiveX DLL, Excel & Access add-ins for Windows Systems to encode these
barcodes.
| Barcode Font Example |
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