The Extended Channel Interpretations (ECI) standard specifies the protocol for extending the interpretative capabilities of basic 7-bit, 8-bit, multi-byte, and 16-bit codes when the data is encoded in data carriers.
Part I defines the protocol. Part II defines the registration process for additional ECIs. Part III is the registry of current ECIs.With the introduction of high-capacity data carriers, the communications aspect of AIDC systems design has become more complex. It is now possible to represent international characters sets, compress and encrypt data, and perform other data carrier specific functions.
It is possible for bar codes and other data carriers to convey general-purpose text (as opposed to serial-numbers, etc.), and this leads to both the opportunities and the difficulties in supporting international character sets. The mapping of graphical characters to binary form varies between countries and between computer operating systems. A protocol is required to convey the identity of the coded character set (i.e., the graphical characters) that was intended when the bar code was printed.
To make practicable use of compression and encryption schemes in high capacity data carriers, a protocol is required so that the receiving system is aware that the decoded data needs some specified expansion and/or decryption processing before its content can be used.
Many high-capacity data carriers provide structured append modes where the concatenated data can exceed the storage capacity of practicable reading equipment. Thus a standard protocol is required so that symbols scanned out-of-order can be identified and sequenced correctly at the receiving system.
Publication date: August 2004