| Standards: Overview of ISS SuperCode |
Overview:SuperCode is a packet bar code symbology, a variant of a multi-row symbology. There are precise rules for the horizontal placement of symbol characters in a packet, but greater freedom in placing packets vertically and horizontally than offered by a matrix of columns and rows in a multi-row symbology.
Basic characteristicsa. Encodable character set: 1. Values 0-127 in accordance with ANSI X3.4, ie all 128 ASCII characters (equivalent to the US national version of ISO 646). 2. Values 128-255 in accordance with ISO 8859-1: Latin Alphabet No. 1. NOTE: This corresponds to ECI 000003. b. Symbol character structure: n,k,m symbology of 16 modules (n), 4 bar elements (k), with the largest element 6 modules wide (m). c. Maximum number of data characters per symbol (at the lowest level of error correction): 1. Alphanumeric data: 4,083 characters 2. 8-bit byte data: 2,546 characters 3. Numeric data: 5,102 digits d. Symbol size: 1. Number of packets: 3 to 1023 2. Maximum codeword capacity: 1023 per single block 2046 per double block 3. Maximum data codeword capacity: 2044 including Symbol Structure Header e. Selectable error correction. 32 levels of error correction requiring 2 to 1056 error correcting codewords per symbol. f. Non-data overhead: 1. Per packet: 1 address codeword 2. Per row: 6 modules for start pattern, 3 modules for stop pattern, 20 modules for quiet zone: a total of 29 modules 3. Per symbol: 2.4 codewords for header plus error correction codeword g. Code type: Continuous h. Character self-checking: Yes i. Bi-directionally decodable: Yes Summary of additional featuresThe following summary is of additional features which are inherent or optional in SuperCode: a. Packet Structure: (Inherent) The packet structure of SuperCode ensures that each symbol character encoding a data or error correction codeword is adjacent to a symbol character encoding the packet address. Thus the sequence of codewords is known no matter how spatially arranged are the packets. Not only does this allow for non-rectangular symbol shapes, but the packets do not have to abut one another physically. b. Error Correction: (Inherent) SuperCode symbols have error correction codewords, based on Reed-Solomon error correction algorithms, which can be used not only to detect errors but to correct erroneously decoded or missing codewords (see ). A user may select one of 32 error correction levels. c. Extended Channel Interpretations (ECI): (Optional) This mechanism enables characters from other character sets (eg Arabic, Cyrillic, Greek, Hebrew) and other data interpretations or industry-specific requirements to be represented (see ). d. Logical Layer Designator (LLD): (Inherent) This mechanism allows various structures of the symbol. Five Logical Layer Designators are specified (see ). One LLD is allocated to the ECI scheme, common to a number of symbologies. |
