Common Programming Interface Communications (CPI Communications)

Common Programming Interface Communications (CPI Communications) is the communication element of the Systems Applications Architecture (SAA) Common Programming Interface (CPI).

CPI Communications in CICS® provides an alternative application programming interface (API) to existing CICS Advanced Program-to-Program Communications (APPC) support. CPI Communications provides distributed transaction processing (DTP) on APPC sessions and can be used in assembler language, COBOL, PL/I, or C.

CPI Communications defines an API that can be used in APPC networks that include multiple system platforms, where the consistency of a common API is of benefit.

The CPI Communications interface can converse with applications on any system that provides an APPC API. This includes applications on CICS platforms. You can use APPC API commands on one end of a conversation and CPI Communications commands on the other. CPI Communications requires specific information (side information) to begin a conversation with a partner program. CICS implementation of side information is achieved using the partner resource, which your system programmer is responsible for maintaining.

Calls from the application to the CPI Communications interface are resolved by link-editing it with the CICS CPI Communications stub (DFHCPLC). For information abut how to do this, see Including the CICS-supplied interface modules.

The CPI Communications API is defined as a general call interface. The interface is described in the z/VM: CPI Communications User's Guide.