The RFC adapter enables you to use the functions of the Integration Engine or PCK in existing SAP system landscapes. The adapter is used by SAP systems to connect to the Integration Engine or the PCK by using the RFC interface. It supports SAP systems as of version 3.1x.
The adapter uses the SAP Java Connector (JCo), making use of its ability to manage metadata. This in turn enables you to map RFC data generically to RFC XML and the other way around.
See: SAP Java Connector
For FAQs about the RFC adapter, see SAP Note 730870.
The parameters that you have to enter for the adapter depend on the Direction you want the adapter to have (sender/receiver).