5
Using Application Link Enabling

An R/3 Application Link Enabling (ALE) system handles the exchange of data messages across applications, ensuring data is consistent. When developing interactions with ALE IDOCs, you must be able to view ALE IDOCs. There are two ways to use Oracle Application Server ProcessConnect and R/3 to search for IDOCs:

Import the Utility Function Modules to automatically explore the R/3 system for existing IDOCs.

See Also:
"Importing the Oracle Application Server ProcessConnect Utility Function Modules"
Manually download the ALE IDOC definitions (*.mtd files) to the Oracle Application Server ProcessConnect computer.

If you do not include the custom browsing function modules for ALE in your R/3 system, you must download the IDOC you wish to view.

This chapter discusses the following topics:

Manually Downloading an IDOC

If you work with only two or three IDOCs, it is recommended that you download the IDOCs manually so you can view the IDOCs when selecting an interaction.

Note:

If you are using IDOCs extensively, it is recommended that you use the enhanced browsing function modules to facilitate the browsing of the ALE IDOCs in the R/3 system.

See Also:

"Installing Oracle AS ProcessConnect Utility Modules in Your R/3 System" to install the custom function modules for browsing purposes.

To manually download IDOC definitions from an R/3 system, complete the following steps:

Log on to an R/3 system.

The SAPGUI Easy Access dialog box is displayed.
From the main R/3 menu, expand Tools > Business Communications > IDOC.

The Process technology tree is displayed.
Expand IDOC > IDOC Basis.
Expand Documentation > IDOC type (parser).

Figure 5-1 Documentation IDoc Record Types and IDoc Types (Parser)

Text description of ale_down.gif follows.

Text description of the illustration ale_down.gif

Click the Basic Types browse button, and select MATMAS01 from the Selection of IDOC types.
Click the check mark to accept and load your selection.
Press F8 or Execute to run.
Select List > Download.
Select unconverted in the Save dialog.
Type the following in the Transfer List to a Local File type matmas02_46B.mtd:
```
ORACLE_HOME/ip/adapters/config/SAP/Cache/IDOCName_SAPVers.mtd 
```
Click OK.
Exit the R/3 session.

You do not have to reestablish a session with R/3 to view ALE IDOCs, because the information has been downloaded and saved on your local computer.

Note:

To refresh existing IDOCs on your Oracle Application Server ProcessConnect machine, delete any existing .ido files for that IDOC from your cache directory.

An MTD is the IDOC structure and an IDO is the binary version of an MTD.

For Your Information

If an IDOC definition is needed, but no *.ido file exists, Oracle Application Server ProcessConnect downloads the *.ido file from an available R/3 system. However, if the R/3 system is down, nothing works. In this case, predownload the IDOC definitions to an .mtd file.

*.mtd files create the *.ido files
*.ido files are compiled versions of the *.mtd file

Calling the IDOC, either by viewing in Oracle Application Server ProcessConnect or being called by the Oracle Application Server Integration Adapter for SAP R/3, creates the *.ido file from the *.mtd ONLY on the initial call. If an *.ido exists in your Cache directory for a specific IDOC, Oracle Application Server ProcessConnect uses the existing *.ido file. If the *.mtd is then updated, the *.ido does NOT automatically update. You must first delete the old *.ido file, then call the IDOC to cause the updated *.mtd to generate a new *.ido.

The Cache directory contains local descriptions of ALE messages.

Files named ".mtd" (IDOCName_SAPVersionNumber.mtd) are created when downloaded using the R/3 RSEIDOC3 file (with only Display structure and Display segment fields set and with only one IDOC type generated). Files of this name are automatically converted to *.ido files. However, *.mtd files do not convert to *.ido files if an *.ido file (with the same name) exists.
Files named "*.ido" are binary files containing the local representation of IDOC messages. These are either downloaded from the R/3 system or they are built from *.mtd files as needed. IDOCs can be accessed at runtime only if the Enhanced Browsing Function Modules have been uploaded.

See Also:
"Installing Oracle AS ProcessConnect Utility Modules in Your R/3 System"

The preferred method is to use the R/3 SAPParser method and download the *.mtd files locally to generate the *.ido.

See Also:
"Manually Downloading an IDOC"

Frequently Used ALE Transactions

Table 5-1 displays a list of frequently used ALE transactions.

Table 5-1 Frequently Used Application Link Enabling Transactions

Transaction	Description
SALE	Application Link Enabling Customizing
BD21	Analyze change pointers - create IDOCs from change pointer
BD12	Send customer master
BD61	Activate change pointer generally
BD54	Maintain logical systems
BD64	Maintain distribution model
BD71	Distribute customer model
BDM2	Cross-system IDOCs reporting
WE02	IDOC Display
WE05	IDOC List
WE20	Maintain partner profile
WE21	Maintain port definition
WE30	Develop IDOC types
WE31	Maintain IDOC segment
WE60	IDOCs Documentation - IDOC types
BDM7	Application Link Enabling Audit - statistical analyses
WE14	Process (dispatch) IDOCs through port - RSEOUT00
WE16	Inbound file
WE42	Process code inbound
SARA	Central IDOCs archive
WE47	Status code maintenance
WE82	Assign IDOCs to message type
SM59	Maintain Remote Function Call destinations
SM37	Display batch jobs - job overview
SM50	Process overview
SLG1	Evaluate application log
SM21	System log
SM58	Transactional Remote Function Call monitoring
RZ12	Remote Function Call Server Group maintenance

ALE Terminology

The following terms are described:

Logical System

A logical system is your R/3 address where you can distribute data to and from an R/3 system. Logical systems start with a base logical system.

A base system uses the case sensitive Remote Function Call (RFC). To browse the Remote Function Call destinations from the SAPGUI interface:

Click Tools > Administration.
Select Network.
Select RFC destination.
Select TCP/IP Connections.
Select the RFC destination to use.

Make sure the RFC destination points to the correct computer using the System Information > Target System. You can also verify your connection using the Test Connection button. Ask the administrator of the logical system which RFC destination to use.

Intermediate Documents (IDOC) Type

An IDOC type represents the structure of the data associated with a message type. An IDOC is a component with the data of a particular message type. Each IDOC contains only one business type.

Before you can send or receive IDOCs of a certain type, the IDOC structure must be defined. An IDOC consists of the following types:

Control Record--Every IDOC has one control record. The control record contains information about the IDOC. For example, it contains the type of IDOC, the message type, sender and receiver information, and direction (inbound or outbound). This information provides control data on an outbound IDOC and processing options on an inbound IDOC.
Data Record--An IDOC contains one or more data records containing application data and consists of one or more data records. Its sequence and structure are dictated by the sequence and structure of segments in a given IDOC type. For an outbound interface, ALE function modules populate these segments with application data. For inbound ALE interfaces, the application modules process the data contained in the segments.
Status Record--With a length of 2 bytes, the status record contains information about the state of the IDOC as it passes through various stages of processing. R/3 assigns values between 01 to 41 for outbound IDOCs and assigns values between 50 to 73 for inbound IDOCs. The status record is a history of the IDOC states containing dates and time stamps.

IDOCs are identified by a unique IDOC number (IDOCNUM) assigned by R/3; however, it is possible to manually assign a number range of IDOCs.

Message Type

The message type represents the data exchanged between R/3 and an external system. A message type characterizes the data being sent across systems and relates to the structure of the data: an IDOC type. For example, MATMAS is a message type for Material Master, and IVOIC is a message type for an Invoice. Over 200 message types are supported by ALE in an R/3 system.

Access logical message types using the /nwedi transaction or by completing the following steps:

Select Development.
Select IDOC types.

Using Environment > Message types retrieves a list of available message types.

To access an assignment of logical message types to IDOC types, complete the following steps:

Select Environment.
Select IDOC types/message.

The main transaction in the R/3 system for IDOCs handling is /nwedi. R/3 documentation is available for IDOC types and IDOC segment types. The IDOC > IDOC lists menu accesses the list of IDOCs created and received in an R/3 system.

Custom IDOC Behavior

The segment type name in a custom IDOC must be compliant with R/3 specifications. For more information on using the R/3 transaction /nWE31, see online help on the field segment type: All R/3 segment types begin with 'E1"; all customer-specific types must begin with 'Z1' or a customer specific prefix (namespace).

AdvancedSend Versus Send

Each IDOC contains two methods: AdvancedSend and Send. Both methods perform the same function; however, the arguments are different.

Send requires a messageType and an IDOC.
AdvancedSend requires controlData and an IDOC

The Oracle Application Server Integration Adapter for SAP R/3 always triggers the AdvancedSend method when it receives an IDOC from an R/3 system; therefore, you must always choose the AdvancedSend method for inbound interactions.

For outbound interactions, you can choose Send or AdvancedSend depending on the method signature that suits your needs. If you use the Send method in your code, Oracle Application Server ProcessConnect takes the ALE Partner Logical System and the Oracle Application Server ProcessConnect Partner Logical System from the values set in the delivery channel. If you use the AdvancedSend method in your code, you have more control, but you must fill in the fields of the controlData argument yourself.

The following are the most useful fields in the controlData structure. Many of the other fields must be left blank.

Field	Description
mestyp	Message type
idoctyp	Basic structure of the IDOC.
cimtyp	Structure of customer extension if applicable.
sndprt	Partner type of the sender; LS (logical system) for ALE.
sndprn	Partner number of the sender; the logical system for ALE.
rcvprt	Partner type of the receiver; LS (logical system) for ALE.
rcvprn	Partner number of the receiver; the logical system for ALE.