Data conversion between the Client daemon and a CICS® server
The ECI and EPI allow non-CICS applications running in a client system to gain access to CICS facilities and data managed by a CICS server system.
Character data may have to be converted as it is passed between client and server; for example data is encoded in ASCII on a client system and in EBCDIC on a CICS mainframe server system. Data conversion is performed by the server system.
The possible ASCII and EBCDIC encoding schemes are described in detail in SC09-2190, the Character Data Representation Architecture Reference and Registry (CRDA). In summary, each encoding scheme is identified by a Coded Character Set Identifier (CCSID) which defines a set of graphic characters and the Code Page Global Identifier (CPGID) which specifies the code points used to represent the graphic characters.
The data managed by the server system may be accessed from several client systems each of which uses a different ASCII encoding scheme. To support such access, each client system must be able to supply a CCSID 'tag' in order that the data is converted correctly.