Required Modules

The two methods described here can be used to access the APPC/MVS system services.

One or more of the following modules from SYS1.CSSLIB must be link-edited with any program that issues APPC/MVS services:
ATBPBI

With programs that issue CPI Communications calls or TP conversation services

ATBATP

With programs that issue APPC/MVS advanced TP services

ATBCTS

With programs that issue APPC/MVS allocate queue services, or the Reject_Conversation or Set_Conversation_Accounting_Information services.

ATBCSS

With programs that issue APPC/MVS system services.

If the load modules are to be executed on a level of APPC/MVS other than the one on which the link-edit is performed, the link-edit should be run using copies of the SYS1.CSSLIB modules from the system on which the load modules will be executed.

After new releases of MVS are installed or maintenance is applied which affects this interface, these modules and any load modules containing copies of them must be link-edited with the APPC/MVS programs again. Therefore, with any APPC/MVS applications that you write, provide a post-install job to link-edit the modules again with the appropriate programs.
A program can issue the MVS LOAD macro for the APPC/MVS service to obtain its entry point address, then use that address to call the APPC/MVS service.

Additional language-specific statements may be necessary so that language compilers can provide the proper assembler interface. Other programming notation, such as variable declarations, are also language-dependent.