GS1 EPC Tag Data Standard 1.6 - Indicod-Ecr

547854795480548154825483548454855486548754885489549054915492549354945495549654975498549955005501550255035504550555065507550855095510551155125513551455155516Now, this OID pair can be assigned a single ID Value of 125 (decimal). TheFormatString column for this entry shows that the encoded data will always consist ofa fixed-length 6-digit string, followed by a variable-length alphanumeric string.Also as shown in Table L-1, OID 3n has an ID Value of 51 (decimal). The OIDscolumn for this entry shows that the OID is formed by concatenating “3” with a suffixconsisting of a single character in the range 30 hex to 39 hex (i.e., a decimal digit). Sincethat is a range of ten possibilities, a four-bit number will need to be encoded in theSecondary ID section to indicate which suffix character was chosen. TheFormatString column for this entry shows that its data is variable-length numeric; thevariable length information will require four bits to be encoded in the Aux Formatsection.Since only a small percentage of the 128-entry ID Table is utilized in this PackedObject, the encoder chooses an ID List format, rather than an ID Map format. As thisis the default format, no Format Flags section is required.This results in the following Object Info section: EBV-6 (ObjectLength): the value is TBD at this stage of the encoding process Pad Indicator bit: TBD at this stage EBV-3 (numberOfIDs) of 001 (meaning two ID Values will follow) An ID List, including: First ID Value: 125 (dec) in 7 bits, representing OID 7 followed by OID 1 Second ID Value: 51 (decimal) in 7 bits, representing OID 3nA Secondary ID section is encoded as ‘0010’, indicating the trailing ‘2’ of the 3nOID. It so happens this ‘2’ means that two digits follow the implied decimal point,but that information is not needed in order to encode or decode the Packed Object.Next, an Aux Format section is encoded. An initial ‘1’ bit is encoded, invoking thePacked-Object compaction method. Of the three OIDs, only OID (3n) requiresencoded Aux Format information: a four-bit pattern of ‘0101’ (representing “six”variable-length digits – as “one” is the first allowed choice, a pattern of “0101”denotes “six”).Next, the encoder encodes the first data item, for OID 7, which is defined as a fixedlengthsix-digit data item. The six digits of the source data string are “061031”,which are converted to a sequence of six Base-10 values by subtracting 30 hex fromeach character of the string (the resulting values are denoted as values v 5 through v 0in the formula below). These are then converted to a single Binary value, using thefollowing formula: 10 5 * v 5 + 10 4 * v 4 + 10 3 * v 3 + 10 2 * v 2 + 10 1 * v 1 + 10 0 * v 0According to Figure K-1, a six-digit number is always encoded into 20 bits(regardless of any leading zero’s in the input), resulting in a Binary string of:“0000 11101110 01100111”Copyright ©2005- 2011 GS1 AISBL, All Rights Reserved. Page 208 of 218