Using the CICS business logic interface to call a program

Figure 1 shows the data flow through the CICS® business logic interface to a program, and back to the requester.

Figure 1. Calling a program with the CICS business logic interface—data flow
This illustration shows the data flow when the is used to call a program. The data flow is described in the text.
  1. The caller of the CICS business logic interface provides a COMMAREA that contains the request to be processed. The contents of the COMMAREA must be in a code page acceptable to the subsequent processes. Usually this means that they must be in EBCDIC.
  2. If the caller requests a converter, the Decode function of the converter constructs the COMMAREA for the CICS application program.
  3. The CICS application program updates the COMMAREA.
  4. If the caller requests a converter, the Encode function of the converter constructs the COMMAREA that is to be returned to the caller.
  5. The CICS business logic interface returns to its caller, which can now use the contents of the COMMAREA.