RFC Processing with the RFC Adapter

The RFC adapter enables you to process and execute RFCs (Remote Function Calls) using the Integration Engine and PCK.

Processing RFC calls using the Integration Engine is an alternative means of processing XML messages that are generated using the proxy interface. This alternative is considered for all SAP applications that already use RFC calls, as well as for new applications of SAP components that do not yet have access to the proxy generation functions.

Prerequisites for the Sender of RFCs

• Existing applications do not need to be changed.
• All sender systems that use the RFC adapter should be maintained in the System Landscape Directory.
• You require an RFC connection of type TCP/IP to the RFC adapter. At this RFC destination, you must register the program ID for the sender adapter that you specified when you configured the sender adapter.

  See: Setting Up an RFC Destination for the RFC Adapter

• You cannot send IDocs using this RFC connection. You must send IDocs to the RFC destination of the IDoc adapter.
• The RFC adapter uses the connection data for the metadata repository to access the required metadata of the called function modules. To do this, a user must be maintained for the SAP Java Connector (JCo).

  See: SAP Java Connector

• The metadata repository is not necessarily located in the sender system. It can also be provided by another SAP system.

Prerequisites for the Receiver of RFCs

• The communication between the Integration Server/PCK and the receiver system does not require an RFC connection or parameters from the configuration of the RFC adapter.

  The communication channels from the Integration Directory or the PCK determine the respective receiver systems.

Process Flow of RFC Communication with the Integration Server/PCK

• The connected systems generate the RFC calls in the applications and send them to the RFC destination of the Integration Engine or the PCK.
• The RFC adapter is called at the inbound channel of the Integration Engine/PCK. It uses the SAP JCo to generate an RFC XML document (XML message) from the RFC metadata and transfers it for further processing.
• A message ID is created for each RFC XML document and a message comprising a header and payload (with the RFC XML document) is sent to the Integration Engine/PCK.
  Note

  Each message only contains one RFC call.

• Incoming RFC XML documents are only persisted if they are based on a tRFC call (asynchronous message processing). Synchronous RFC calls (sRFCs) are only persisted if logging is activated.
• The RFC adapter at the Integration Engine outbound channel requires a communication channel from the technical routing for each receiver from the logical routing.

  You define this communication channel during configuration of the receiver adapter in the Integration Directory. It is analyzed and provides the technical information for the RFC call.

• The RFC adapter does not make any special demands on mapping. It simply requires an RFC XML document in a format that is supported by the SAP Java Connector. This document either already exists or must be generated using a mapping.
• At the outbound channel of the Integration Engine/PCK, the system calls the RFC adapter and transfers the RFC XML document (XML message) with the communication channel parameters.
• The task of the receiver RFC adapter at the Integration Engine/PCK outbound channel is to convert RFC XML to a valid RFC call and to execute this call.

  In the case of a synchronous RFC call, the result of the call is accepted by the RFC Adapter, converted to XML (RFC XML response) if necessary, and returned to the Integration Engine/PCK for further processing.