SAP EDI Outbound Process with Message Control

Processing in the Application Layer

An application document is entered via a transaction.Before an application document is saved, the Message control component is invoked. An application passes several key elements of the application data to the Message control component via communication structures.

Processing in the Message Control Layer

The Message control component checks various business rules defined in the Message control configuration. Based on the business rules, Message control proposes the output type ,medium and language of the message. Multiple outputs are possible from Message control. Each output is processed independently.

The output proposed by the Message control component can be edited. The user can delete, add, or modify any outputs proposed on the output control screen.

When the application document is saved, the outputs proposed on the output control screen are saved as a record in the NAST table. An entry in the NAST table stores the key of the application document, output type, timing, processing status, and language.

If the timing for an output is set to 4 (Immediate), the system immediately starts the processing of the output type by executing the RSNAST00 program. If the timing is set to 1 (Batch Mode), the entries are processed when the RSNAST00 program is executed explicitly.

The RSNAST00 program is usually scheduled to run on a regular basis. It selects entries that can be processed based on their status and calls the appropriate program for the selected medium. Each output medium (EDI, ALE, fax, printed output, and so on) has a corresponding program to generate the output in the required medium. SAP provides standard processing programs for each output medium.

In the case of EDI, the processing program is a form routine: EDI_PROCESSING in the RSNASTED program. This program is a generic program for all EDI outputs and reads the partner profile configuration to determine the selection program for a particular message.

In ALE, the processing program is also a form routine: ALE_PROCESSING in the RSNASTED program. This program is a generic program for all ALE outputs and reads the partner profile configuration to determine the selection program for a particular message.

Processing in the Selection Program

The selection program is specified in the partner profile with a process code. The RSNASTED program calls the appropriate selection program.

One of the parameters for these function modules is the NAST entry, which contains the key of the application document. These programs extract application data, format it into an IDoc format in an internal table, and then pass control to the ALE/EDI layer.

Processing in the ALE/EDI Layer

The ALE/EDI layer is responsible for creating the IDoc in the SAP database. By now, a tangible IDoc that can be viewed using the various monitoring tools has been created in the system. The IDoc gets a status record with a status code of 01 (IDoc Created).

The IDoc, before being saved in the database, goes through a syntax check and other validations. If there are no errors, the IDoc gets a status of 30 (IDoc Ready for Dispatch to ALE Service).

Dispatching the IDoc

The settings of the Output Mode fields in the partner profile are read to determine the timing of dispatching idoc,and the port definition is read to determine the directory location in which the file will be created. If the mode is set to Do Not Collect IDocs, the IDoc isimmediately passed to the operating system layer automatically, using program RSEOUT00.

The subsystem takes the IDoc file as input and translates it into an EDI standard format. At various milestones, the subsystem reports the status of the process to SAP, thus providing complete visibility into the process from within SAP. The status reported by the subsystem is attached as a status record to the IDoc in the SAP database.

To report status back to the SAP system, the subsystem creates a status file at the OS level and calls the function module EDI_STATUS_INCOMING in SAP, passing the status file name as an input parameter. For this, SAP provides a standard program named startrfc at the OS level to execute any RFC−enabled function module in SAP.