Behavior of COBOL CALL API in TXSeries programs
What are the requirements for using a CALL API in a TXSeries CICS COBOL programs ?
Whenever a CICS COBOL application calls a C, C++ or COBOL program using CALL API, it is not required to define the called program as a Program Definition (PD) entry in TXSeries region. The COBOL runtime can recognize the called program from COBOL installed path. (See http://www-01.ibm.com/support/docview.wss?uid=swg21591360 for more details about the program path).
If the COBOL program calls a C, C++ or COBOL program containing CICS commands, you need to define a Program Definition (PD) entry in the TXSeries region. It is recommended that you use EXEC CICS LINK or EXEC CICS XCTL APIs to run the program rather than using the COBOL CALL API.