RFC call betwen two SAP systems
From your SAP system this allows you to call source code contained within an RFC function module on a seconed SAP system. Using an RFC call between two SAP systems is a fairly simple process, all you have to do insert a 'CALL FUNCTION' statement with the addition of the 'DESTINATION' parameter pointing to your destination SAP system. A list of RFC destinations can be viewed via transaction SM59 or by looking in table RFCDES.
* Call a function module on a connect SAP system * See Tcode SM59 for list of RFC Destinations call function 'Z_GET_USER_IDS' destination 'DEV_500' importing userid = ld_userid.