Communications Basis CPI-C

Definition

The Common Programming Interface - Communications (CPI-C) is a standard call interface for applications, which perform direct program-to-program communication.

CPI-C was first defined as a standardized communications interface by IBM in 1987, as part of the SAA standard.

CPI-C was modified by X/Open to include additional functions. SAP's CPI-C implementations support the X/Open Developers' Specification - CPI-C.

The main advantage of CPI-C is the easy portability of programs to various system platforms made possible by the common interface.

Use

The CPI-C communications interface essentially fulfills the following requirements of program-to-program communication:

Structure

The CPI-C interface can be split into two function groups. This division does not, however, imply limitations in respect of possibilities to use and combine the functions. The function groups are there merely to guide the user:

CPI-C Starter Set

These basic functions represent the minimum range of functions shared by two partner programs:

As these are the basic functions of a communication protocol, it is possible to reproduce the CPI-C Starter Set on protocols other than LU6.2.
The SAP CPI-C development library cpictlib is an example of mapping to TCP/IP.

Advanced Function Calls

These advanced functions essentially cover the following task areas:

The CPI-C Starter Set functions are carried out in the CPI-C interface from ABAP and in the platform-specific SAP CPI-C development libraries for programs written in C. The libraries also contain some Advanced Function Calls.

For details on configuration, refer to the following documentation:
SAP Communication: Configuration