Hi everyone,
If you look at the heel of a glass bottle you will find different casting marks defining the bottle shape, production date and a "dot code" defining the casting number(Regulated by DIN 6121 for example). For the dot code, there are different codings(9 dots, 8 dots, 10 dots, 6 dots mini code). They encode the mold number, which is oftentimes printed in plain text alongside. But there is no information on how the dot code encodes the number. There is the patent for the code reader itself(EP0256804B1) which gives some clues. There are two start and end dots, there are always 9 positions in between, for which 5 are always set. There is a maximum of two consecutive not set positions. This gives around 71 different possibilities(might be wrong, drunk back of the envelope calculation).
I am looking for the encoding scheme or the knowledge, that there is none and it is just a look-up table.
Has anyone of you more information on this? Google failed me hard on this.