Explaining the Receiver Remote Function Call (RFC) Adapter

Objective

After completing this lesson, you will be able to check RFC signatures

RFC Adapter Architecture

You require the Remote Function Call (RFC) adapter for scenarios in which systems are connected to the Integration Server using the RFC protocol. The RFC adapter is part of the Adapter Engine.

The different message types in the RFC adapter are as follows:

Inbound
A message is sent from the sender system and sends in the RFC data format to the sender RFC adapter. This could, for example, be an RFC call executed in a report. The sender RFC adapter creates a message in the XML format from this message and adds the SAP PI metadata (business system, interface, and namespace) required for pipeline processing.
Outbound

The pipeline sends a message in the XML format to the receiver RFC adapter. The adapter function module, which is a remote-enabled function module, is then called in the target system.

Hint

The adapter requires the metadata of the function module interface (for example, data structures and data types) to convert between the RFC format and the SAP PI XML format. Access to the Metadata Repository (MDRS) is then required and this metadata is temporarily stored in the metadata cache of the RFC adapter.

Features of the RFC Adapter

The RFC adapter supports the following features:

  • Synchronous Remote Function Calls (sRFCs) in messages with quality of service (QoS) and Best Effort (BE) are available.

  • Transactional Remote Function Calls (tRFCs) in messages with quality of Exactly Once (EO) are available.

  • Messages with QoS Exactly Once In Order (EOIO) mapped to tRFC are available.

  • SAP GUI, callbacks, and queued remote function call (qRFC) are not required.

  • Stateless calls are available.

  • Additional attachments are not required.

  • Unicode and non-Unicode systems are available.

Hint

Only the Intermediate Document (IDoc) adapter can process IDocs.

External programs that have been created using the RFC Software Development Kit (SDK) can only be connected if the metadata for the interface used is available in an SAP system.

Stateless calls are multiple calls that are executed in the target system cannot be grouped in a single context. Therefore, there is no transactional context for more than one RFC call per Logical Unit of Work (LUW).

RFC Signature in the Enterprise Services Repository (ESR)

In design time, you must import the interface of a remote-enabled function module from the business system into the ESR for the corresponding Software Component Version (SWCV) in the same way that you import IDoc types.

The RFC signature is not assigned to a namespace of the SWCV but is automatically given the namespace urn:sap-com:document:sap:rfc:functions.

The RFC signature can be assigned to an SWCV even if the function module was not actually developed on the basis of this software.

Unlike IDoc types, RFC signatures contain three message types describing the interface parameters during the call (request), reply (response), and in the case of errors (fault). This view of the interface parameters of a remote-enabled function module can also be seen at runtime in the XML messages.

Hint

The message types are not listed separately under Message Types. They are only visible in the RFC signature.

RFC Signature and Message Types

The request is the remote-enabled function module call and it corresponds to the import interface and the table interface of the remote-enabled function module. The response corresponds to the export interface and the table interface. If the remote-enabled function module triggers an exception, it is handled as a fault message type.

Note

Even though the table interface parameters are not required for the call, they are listed in the request message type. For example, the RETURN table may only return information about the success or failure of the call. The table is not used to transfer data to the remote-enabled function module.

The message types of an imported RFC signature can be referenced directly in a service interface. This reference enables you to model an RFC-enabled function module that exists in the target SAP system in the ESR as a service interface. You can then create a server proxy in the SAP system (Release 6.20 and higher) and use the function module during implementation. In this way, the function module can use SAP PI Simple Object Access Protocol (SOAP) without an RFC adapter.

You can only edit the imported RFC signature in the request message type to reference context objects for routing.

You configure the RFC adapter in a communication channel. You also require sender and receiver agreements to establish a connection between the communication channel and the interface of the function module.

How to Import an RFC Signature

DemoStart Demo

Check RFC Signatures in the Enterprise Service Repository (ESR)

Business Scenario

You need to use an RFC interface in a scenario. To do this, you must import the message interface into the ESR as an RFC signature.

Exercise Information

Note

In this exercise, when the values include ##, replace the character with a two-digit number (01–30).

Note

The exercises in this course were tested with Microsoft Internet Explorer. If you use any other browser, the behavior in some exercises might be different.

Exercise Options

You can perform this exercise in two ways:

  1. Live Environment: choose Start Exercise, and from the entry page choose Open PDF Document. Follow the steps described in this pdf in your own system landscape.
  2. Simulation: choose Start Exercise, and from the entry page choose Start Tutorial. Watch the step-by-step instructions within the simulation.

Note

We recommend running the simulation first.
ExerciseStart Exercise

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