Plessey’s barcode pattern is so simple that, with casual familiarity with the code, you can actually read the bar codes with your eyes.
Plessey basic code rule is:
- Wide bar following by narrow space is a "1" bit.
- Narrow bar followed by wide space is a "0" bit.
And each digit number is represented by four bit.
If you only calculate the bar (horizontal black line), the wide bar means ‘1’ and the narrow bar means ‘0’.
So, the digit ‘1’:
- BCD (Binary- Coded Decimal) is 0001b
- reversed BCD is 1000b
- wide bar + narrow bar + narrow bar + narrow bar
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| 1.2.1. An Example |  | 1.2.3. Barcode Format |
