Summary of data conversion for CICS intercommunication functions

Data conversion is required when the code page that is used in a CICS® transaction is different from the code page that is used for the resource. The resource can be a file or a temporary storage or transient data queue; or a program, a transaction, or a terminal.

Data conversion has to be considered for:
  • Function shipping, distributed program link, and asynchronous processing
  • Transaction routing
  • Distributed transaction processing

The data conversion requirements for the three intercommunication functions are different. Also, these requests might appear as outbound or inbound to the TXSeries for Multiplatforms region. That is, an application on a TXSeries for Multiplatforms region might initiate a function-shipping request to a remote system (an outbound request), or a remote system might initiate a function-shipping request to a resource that is owned by the TXSeries for Multiplatforms region (an inbound request). Key points are described in the following sections:
Function shipping, distributed program link, and asynchronous processing
  1. On the resource-owning system, define a data conversion template for the resource as defined in Standard data conversion for function shipping, DPL and asynchronous processing. Each resource, such as a file or a temporary storage queue, must have a template defined for it if its data is to be converted. These templates indicate how each field in the resource is to be converted.
  2. Generate the conversion template by using cicscvt.
  3. Place the template on the appropriate directory, for example: 
    varDir/cics_regions/region/database/FD/FILE.cnv
  4. Set the TemplateDefined attribute in the resource definition entry for the resource to yes. This attribute specifies that a template exists for the resource.
Transaction routing:
  1. Set the RemoteCodePageTR attribute in the Communications Definitions (CD) entry for the remote system to the code page that is to be used to flow transaction routing data.
  2. You can customize the transaction routing user exit, DFHTRUC. This user exit converts the COMMAREA and the TCTUA that flow with the transaction routing data. Refer to Writing your own version of DFHTRUC for further details.
Distributed transaction processing:
  • Because DTP programs use application specific data areas, CICS cannot supply data conversion macros or user exits for DTP. The technique that you use is determined by the design of your application.
A full description of the data conversion requirements for the three intercommunication functions is given in:
Parent topic: Communications