GS1 EPC Tag Data Standard 1.6 - Indicod-Ecr

482048214822482348244825482648274828482948304831483248334834483548364837483848394840484148424843484448454846484748484849485048514852PO Index Field PO Index Field Object Optional ObjectOffsets subsectionfor first ID Map for second ID Map OffsetsPOindexLengthPOindexTablePOindexLengthPOindexTablePresentbitObjectOffsetsMultiplierObject1offset(EBV6)Object2offset(EBV6)… ObjectNoffset(EBV6)Each PO Index Field has the following structure and semantics:A three-bit POindexLength field, indicating the number of index bits encoded foreach entry in the PO Index Table that immediately follows this field (unless thePOindex length is ‘000’, which means that no PO Index Table follows).A PO Index Table, consisting of an array of bits, one bit (or group of bits, dependingon the POIndexLength) for every bit in the corresponding ID Map of this directorypacked object. A PO Index Table entry (i.e., a “PO Index”) indicates (by relativeorder) which Packed Object contains the data item indicated by the corresponding ‘1’bit in the ID Map. If an ID Map bit is '0', the corresponding PO Index Table entry ispresent but its contents are ignored.Every Packed Object is assigned an index value in sequence, without regard as towhether it is a “parentless” Packed Object or a “child” of another Packed Object, orwhether it is a Data or Directory Packed Object.If the PO Index is within the first PO Index Table (for the associated ID Map) of theDirectory “chain”, then: a PO Index of zero refers to the first Packed Object in memory, a value of one refers to the next Packed Object in memory, and so on a value of m, where m is the largest value that can be encoded in the PO Index(given the number of bits per index that was set in the POindexLength), indicatesa Packed Object whose relative index (position in memory) is m or higher. Thisdefinition allows Packed Objects higher than m to be indexed in an AddendumDirectory Packed Object, as described immediately below. If no Addendumexists, then the precise position is either m or some indeterminate position greaterthan m.If the PO Index is not within the first PO Index Table of the directory chain for theassociated ID Map (i.e., it is in an Addendum IDMPO), then: a PO Index of zero indicates that a prior PO Index Table of the chain provided theindex information, a PO Index of n (n > 0) refers to the nth Packed Object above the highest indexvalue available in the immediate parent directory PO; e.g., if the maximum indexvalue in the immediate parent directory PO refers to PO number “3 or greater,”then a PO index of 1 in this addendum refers to PO number 4.Copyright ©2005- 2011 GS1 AISBL, All Rights Reserved. Page 188 of 218