SAP FICO IDoc Interfaces for Data Transfer to the RW Interface

RW Interface in the SAP R/3 System

The RW interface (RWIN) is the central interface for transferring postings from other application components in the SAP R/3 System to Accounting. The RW interface controls updates of actual data in Accounting and carries out checks from the Accounting standpoint.

Actual data relevant to Accounting from other SAP R/3 application components first transfers to the RW interface. The interface then sends the data to the appropriate Accounting application component (such as Asset Management, Financial Accounting, Cost Center Accounting, Profit Center Accounting, Profitability Analysis, and so on).

Billing data from the Sales and Distribution (SD) application component transfers to the RW interface. The interface creates the relevant Accounting documents (CO document, FI document, and so on).

IDoc Interfaces to Other SAP R/3 Systems

If you use distributed systems (Application Link Enabling = ALE), the RW interface takes all actual data relevant to Accounting from other SAP R/3 Systems, but not data from the Accounting application components of the other SAP R/3 Systems.

Billing data from the Sales and Distribution (SD) application component in another SAP R/3 System transfers to the RW interface.

IDoc Interfaces to External Systems

The RW interface uses an intermediate document (IDoc) interface, which supports transfers of business transaction-based data from external systems to Accounting application components in the SAP R/3 System.

The IDoc interface for the RW interface can transfer data from the following business transactions:

• Goods movement

• Billing

• Invoice receipt

Billing data can update to the Profitability Analysis (CO-PA) application component.

The IDoc interface fulfills the Open Application Group (OAG) communication structure for the following Business Object Documents (BODs):

• Post Journal (goods movement)

Communication between logistics and accounting systems

• Load Receivable (billing)

Transfer of a billing document from an external system. Along with billing information, the IDoc includes segments with characteristics and value fields for Profitability Analysis.

• Load Payable (invoice receipt)

Transfer of an invoice receipt from an external system or transfer of an invoice receipt to an external system

• Confirm BOD

Confirmation of the successful processing of a received Business Object Document or sending of error messages

The IDocs for the business transactions can be provided with data through the BODs.

The data, once prepared for the RW interface, generally results in general ledger (G/L) postings and postings in the subsidiary ledgers for customers and vendors in the Financial Accounting (FI) application component. The integration of the SAP R/3 System ensures that other Accounting components have access to this data.

The IDoc serves as the source document for all other documents created in the SAP R/3 System. The connection between the IDoc and the follow-on documents is the document number in the external system or in the other, distributed, SAP R/3 System. You can also display the IDoc from the line item display.

Data Transfer to the RW Interface

The following graphic illustrates the data transfer to the RW interface in the SAP R/3 System.

Outbound System

The outbound system (either an external system or another SAP R/3 System) writes documents on the basis of business transactions made. The data transfers to the IDoc interface of the outbound system, whereupon the outbound IDoc moves to the BOD structure.

Inbound System

The inbound system (an SAP R/3 System) also possesses an IDoc interface. Inbound IDocs are provided with data through the BODs.

The following table shows the IDocs and message types that exist in the SAP R/3 System.

Business transaction	IDoc	Message type
Goods movement	ACPJOU01	ACPJMM
Billing	ACLREC01	ACLREC
Invoice receipt	ACLPAY01	ACLPAY

The individual business transactions have the following check modules, which verify the corresponding coding block. These check modules belong to function group ACC3.

Business transaction	Check module
Goods movement	ACC_CODINGBLOCK_CHECK_PJMM
Billing	ACC_CODINGBLOCK_CHECK_LREC
Invoice receipt	ACC_CODINGBLOCK_CHECK_LPAY

An IDoc contains the mandatory and optional fields for the BODs along with SAP-specific fields, which are all optional fields. If, during data transfer via the IDoc interface, only mandatory fields are filled, the SAP R/3 System functions cannot be used to their maximum capacity.

The data is transferred to one of the following function modules (FM) according to the business transaction:

• IDOC_INPUT_ACPJOU (goods movement)

• IDOC_INPUT_ACLREC (billing)

• IDOC_INPUT_ACLPAY (invoice receipt)

The function modules prepare the data for the RW interface and create the appropriate RW document. When preparing the IDocs, the function modules also check whether all mandatory fields are filled and convert ISO-normed units of measure, currencies, and currency units, as well as other fields, into SAP standard fields.

The RW interface function modules include customer functions for modifying a line before it is included in the RW document (for example, to insert additional data).

If no errors occur when the function modules process the data, it is transferred to the RW interface for further processing.

Errors during data processing in the function module result in status messages documented by the IDocs and their inclusion in an error log. The outbound system can receive a response IDoc (a confirm) informing of error messages or of the successful completion of the IDoc processing. The response IDoc transfers via the IDoc interface of the SAP R/3 System to the outbound system and can be converted into a BOD.

The following errors can occur during IDoc processing:

• Error during checks of the transferred mandatory fields

• Error during the conversion of the unit of measure from the ISO norm to the SAP standard

• Error during the conversion of the currency from the ISO norm to the SAP standard

• Error during the conversion of the other fields to the SAP standard

• Error during checks of the RW document by the RW interface

Preconditions and Requirements

Synchronisation of the outbound and inbound systems is mandatory; the same account assignment objects must exist in both systems during the data transfer.

In the inbound system, ensure before data transfer that the required account assignment objects exist. During the transfer, the RW interface checks whether the account assignment objects used in the IDoc actually exist.

Limitations in Comparison with an Integrated System

You cannot make real reverse postings, which only use the document number to be reversed. The document number, however, can be given to the inbound system as part of a reverse posting. The number updates to the individual SAP R/3 application components together with the document. The document to be deleted is thereby flagged.

IDoc Structure

For more information about the structure of IDocs and their documentation, proceed as described in Displaying IDoc Type and Segment Documentation.