What are data segments in GS1 DataBar / RSS Expanded?
GS1 DataBar Expanded (alias RSS Expanded) symbols are constructed as a sequence of triplets, each consisting of a finder pattern between two symbol characters. Such a triplet contains 2 data segments (symbol characters). 2 segments forming a “triplet” consist of 17+15+17 modules. The left and right guard pattern for the symbol consist each of 1 bar + 1 space. Per segment/data character you can encode 12 bits. Each symbol is prefixed with a check character. So the smallest symbol, which uses at least 4 symbol characters (containing 1 check char) can encode 36 Bits. Input data is processed with a character set mapping algorithm + error recognition. With a simple formula it would be hard to predict how many data segments are required for a given set of input characters.
