Types of conversion

The possible types of conversion are:

Standard conversion
This applies to:
No conversion
This applies to:
User-defined nonstandard conversion
You can apply nonstandard data conversion by writing your own version of the user-replaceable conversion program. If specified, a user-defined conversion is applied instead of the standard conversion.

You can apply user-defined conversion to selected fields, and leave others to be converted by the CICS® standard conversion program.

For all CICS on System/390 products other than CICS TS for z/OS®, Version 2.2 and later, to take advantage of nonstandard conversion you must provide a single data conversion program named DFHUCNV. This will probably be a customized version of the DFHUCNV program supplied with CICS.

For CICS TS for z/OS, Version 2.2 and later, you can provide either:

  1. Your own, customized, version of DFHUCNV, or
  2. One or more differently-named conversion programs

If the nonstandard conversion applies only to character data, you may not need to write your own data conversion program. Instead, you could create your own conversion tables for use with the standard conversion program, DFHCCNV. See User-defined conversion tables.

Important

Your user-supplied conversion program must not convert any data that the standard conversion program attempts to convert. Double conversion gives unpredictable results. To ensure that double conversion does not occur, your conversion program must convert only fields defined as DATATYP=USERDATA (see the DATATYP option of the DFHCNV TYPE=FIELD macro).

Related concepts
Where data conversion takes place
Function shipping and DPL
Distributed transaction processing
Transaction routing
Character data
Binary data
The conversion process
User-defined conversion tables
Example macros
The user-replaceable conversion program
Related tasks
Avoiding data conversion
Resource definition to enable data conversion
Defining the conversion table
Assembling and link-editing the conversion programs
Related reference
Where data conversion takes place
Character data
Defining the conversion table
The user-replaceable conversion program
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