Data Flow: EWM Receives Data (SAP Library - SAP Extended Warehouse Management (SAP EWM))

Data Flow: EWM Receives Data

Purpose

The data flow via the interface between the non-SAP system and Extended Warehouse Management (EWM-WCU interface) is explained using an example communication process flow for transmitting data for the warehouse task (WT) from the non-SAP system to EWM.

For more information about the business background, see Scenarios for Connecting Non-SAP Systems.

Prerequisites

You have defined the necessary TCP/IP settings. For more information, see SAP Communication: Configuration.

You have configured the ALE interface in Customizing for Extended Warehouse Management under Interfaces ® Non-SAP Systems ® Connect Subsystem.

Process

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1. The non-SAP system saves the data relevant for transmission to the SAP system, and prepares this data for transmission as an IDoc.

2. The external system transfers the IDoc with an appropriate program.

The transmission is based on Remote Function Call (BC-ABA). For more information, see Programming with the RFC API.

The central function module is in the ALE layer. As soon as the external system calls the function module on the SAP system side, the external system can transfer several IDocs.

Note

If an IDoc type only supports single transmission, then the IDoc system documentation explicitly states this fact.

3. Status management for the data to be transferred should prevent the external system from not transferring data.

Note

If the non-SAP system cannot successfully transmit IDocs, you must ensure that the non-SAP system transmits these IDocs again at a later point.

4. The SAP system should be able to recognize IDocs that have been transferred by the external system already. This is made possible by the unique transaction identification number (transaction ID), which the SAP system assigns for each communication process. For more information, see Structure link Transactional RFC Client Programs.

The non-SAP system must always flag the transmitted data with this transaction ID. If the non-SAP system re-transmits an IDoc due to a previous problem with communication, then the non-SAP system must specify the same transaction ID again.

Caution

The SAP system does not use the IDoc number to recognize a double transfer of IDocs from the external system.

5. The SAP system receives the transmitted IDoc using ALE, saves the IDoc in the database, and reports the receipt of the IDoc to the non-SAP system.

6. Asynchronously to the receipt of the IDoc, ALE transmits the IDoc to EWM, which then takes over processing of the IDoc.

7. EWM uses the transmitted data as the basis for creating warehouse tasks.

8. For each IDoc, EWM reports the processing status to ALE.

ALE uses the processing status to trigger error processing for the IDoc.

Error Processing

If you receive an IDoc from the non-SAP system in EWM, the following problems can occur:

Troubleshooting

Symptom	What You Should Know
There is no connection between the external system and the SAP system	The non-SAP system should use status management to ensure that the non-SAP system re-transmits the IDocs again at a later point.
Error in the ALE interface: There are syntactical errors in the data that the external system sent to the ALE	Although ALE copies the IDoc and saves it, ALE cannot transmit the IDoc to EWM for processing. For more information, see IDoc Error Processing.
Error in the ALE interface: ● Inbound partner profile for the sending system ● IDoc message type are not defined	For more information, see IDoc Error Processing.
Error in the application for EWM	If processing of the received IDoc did not proceed correctly, EWM transmits the relevant processing status. For more information, see Processing Logical IDoc Errors in EWM.