The information about the target system of an RFC call is stored in the RFC destination. These destinations are administrated in the AS ABAP using the transaction SM59. Among other things, the connection type, the partner program, and the target system are specified there. Logon data and further connection options can also be defined in the destination.
A detailed description of the RFC destination can be found in the SAP Library under:
- RFC Destination
- Maintaining Remote Destinations
There are two predefined destinations that do not have to be entered using transaction SM59:
- Destination "NONE"" causes the function module to start on the same application server as the calling program, though using the RFC interface and in its own context and in a separate user session. This destination is possible for all execution modes.
- Destination "BACK" can be used in a function module that is called remotely, and links back to the caller. You can only specify this in function modules that have been called synchronously. Destination "BACK" can be used to call each remote-capable function module of the calling system in all three execution types. For synchronous callback, the relevant function group is loaded into the internal session of the calling program, if it is not yet available there. The existent RFC connection is used for this callback.
As well as the destinations created in transaction SM59 and the two predefined destinations, you can also specify destinations directly, in the form "hostname_sysid_sysnr". "hostname" is the host name of the application server, "sysid" is the name of an AS ABAP, and "sysnr" is the system number as it is displayed using the SM51 transaction.