DFHCNV - The data conversion macros

Note: DFHCNV macros are generally portable between CICS® systems. Some minor changes might be required. See When TXSeries for Multiplatforms does not convert the data for information about the differences between CICS systems.
The following descriptions provide overview information for using the macros:
DFHCNV TYPE=INITIAL
Establishes the beginning of the macro source conversion table. INITIAL is used to set up the control section for the table. It is also used to specify the default code page that represents how data is stored for all resources on your system. (This can be overridden at the resource level.) A shortcode can be used.

Refer to Table 1 for a list of the shortcode and code pages that are supported by the TXSeries for Multiplatforms systems.

This macro can also be used to specify a code page for the incoming request. The TYPE=ENTRY macro overrides this.

Note: TXSeries for Multiplatforms flows a code page in the PIP data. When a code page is flowed to TXSeries for Multiplatforms, the flowed code page is used instead of the code page that is specified with the TYPE=INITIAL macro. See When TXSeries for Multiplatforms does not convert the data for information about which CICS systems flow code pages.
DFHCNV TYPE=ENTRY
Specifies how data conversion is to occur for a specific resource. Code page information that is specified with the TYPE=ENTRY macro overrides code page information that is specified with the TYPE=INITIAL macro.
The TYPE=ENTRY macro is also used to indicate whether or not a standard or nonstandard conversion is required. If a standard conversion can be used, the TYPE=SELECT and TYPE=FIELD macros are used to specify the field lengths and the type of data that is contained in the fields, such as character, binary, MBCS (graphic), or packed decimal. If a nonstandard conversion is required, the TYPE=ENTRY macro is used to specify that a user exit is required (described in Non-standard data conversion (DFHUCNV) for function shipping, DPL and asynchronous processing). Standard conversions can be used when:
  1. The field contains data that can be converted with a type that is specified with DFHCNV TYPE=FIELD DATATYP.
  2. The fields are fixed length.
DFHCNV TYPE=KEY
Indicates the start of conversions to be applied to a key. This is applicable only when the resource is a file with key (KSDS file).
DFHCNV TYPE=SELECT
Declares the selection criteria for a particular conversion. SELECT cannot be used if a nonstandard conversion is specified.
DFHCNV TYPE=FIELD
Specifies field offsets and the type of conversions that are required. FIELD cannot be used if a nonstandard conversion is specified.
DFHCNV TYPE=FINAL
Concludes the macro source conversion table definition. This must occur only once, as the last definition.
Parent topic: Communications