The RFC Interface
A remote function call (RFC) is when a function module is called that runs in a different system to the calling program. Although it is also possible to call a function module in the same system as an RFC, RFCs are normally used when the caller and the called function module run in different systems.
In the SAP system, these functions are provided by the RFC interface system. The RFC interface system enables function calls between two SAP systems, or between an SAP system and an external system.
The RFC- interface system is made up of the following interfaces:
● Calling interface for ABAP programs
● Every ABAP program can call a remote function module using the command CALL FUNCTION...DESTINATION. Parameter DESTINATION informs the SAP system that the called function module is running in a different system to the calling system. RFC communication with the remote system takes place as part of the CALL FUNCTION command.
● RFC function modules in an SAP system must be proper function modules and must be registered in the SAP system as remote.
● If the calling program and the called program are both ABAP programs, the RFC interface provides both communication partners. The calling program can be any ABAP program, while the called program must be a function module that is registered as remote.
● For more detailed information on calling function modules that are registered as remote, see Calling RFC Function Modules in ABAP.
● For more information on writing function modules that you want to call remotely, see Writing RFC Function Modules in ABAP.
● Interfaces for calling non-ABAP programs
If either the calling program or the called partner is not an SAP program, this program must be programmed in such a way that it can play the role of the other partner in RFC communication.
For help while implementing RFC partner programs in non-SAP systems, see: Components of SAP Communication Technology
RFC-supported and GUI-supported interfaces can be used by external programs to call function modules in SAP systems and to perform them in these systems. ABAP programs can also use these interfaces to use functions supplied by external programs.