SAP SD SUPORTE: ALE,IDOC

ALE Technology : Application Link Enabling (ALE) is a technology to create and run distributed applications. ALE Technology is proprietary of SAP.
ALE Objectives - ALE incorporates controlled exchange of data messages ensuring data consistency across loosely coupled applications. ALE comprises of three layers. Application Services Distribution Services and Communication Services .Basic principle of ALE is to provide a distributed and fully integrated R/3 system. Each application is self-sufficient. The use of self-sufficient system implies a certain measure of data redundancy.Hence data has to be both distributed and synchronized.
Difference Between ALE and EDI :Normally we refer to EDI technology when a non SAP system is one of the communication channel. ALE communication occurs from the SAP side and EDI from the non-SAP side. IDOCs uses ALE and EDI to deliver the data to the receiving system. If the data needs to be exchanged between two SAP systems, then IDOC uses ALE technology . For the exchange of data between a SAP and Non SAP system, IDOC uses EDI subsystem to convert and deliver the data.
ALE Communication Diagram

1. What is the difference Between IDOC type and Message type? How to link the IDOC type with Message type?
Message type gives the meaning of the IDOC . IDOC type gives the structure of an IDOC.The messages exchanged between systems are of various message types. The message type depends on the data contained and the process involved. It determines the technical structure of the message and the IDOC type.The IDoc type indicates the SAP format that is to be used to interpret the data of a business transaction.
In the OO(Object Oriented) approach, Message Type can be refferred to a Class and IDOC Type as an instance of the class Message Type
The linkage will happen in transaction WE82.

2. Where the IDOC information gets stored?

Table	Description
Table	Description
EDIDC	Stores the Control Record information an IDOC
EDID4	Stores the Data Records (version 4.6)
EDIDD	Data Seg (EDI Intermediate doc)
EDIDS	Stores the Status of an IDOC

3. What is process code? What are type of process codes
Process code refers to an workflow or a function module which helps in reading or writing data from/to Idoc. Process Codes are used in both ALE and EDI framework to identify the function module or API (Application Programming Interface) to be invoked for subsequent processing. Inbound as well as outbound interfaces use process code but for different purposes. Outbound process codes are stored in table TEDE1, while inbound process codes are stored in TEDE2.
Following are types of process code

Process Code	Description
Process Code	Description
Outbound Process Code	This will read application data and place data in Idoc
Inbound Process Code	This will Idoc and create corresponding application data
System Process Code	This will create work item in case some error occurs in idoc / application document processing
Status Proces Code	This will handle error that occurs when a idoc is sent to some other system

4. How to reprocess an IDOC?
You can use the below Programs for IDocs Reprocessing:

RBDMANI2 : Reprocess Idocs manually
RBDMANIN : Posting of IDocs with Status 51
RBDMOIND : Outbound Idocs status 03->12
RSEOUT00 : For Processing 30 Status IDocs
RBDAPP01 : For Processing 64 Status IDocs
RBDAGAIN : Reprocess Incorrect Outbound IDocs
RBDAGAI2 : Reprocessing of IDocs after ALE Input Error

5. How to trace the IDocs of the Receiving system from the Sending system?
Steps:

Execute the transaction BD87
Give the Outbound IDocs in the IDoc Number field and execute or Just Note the Start time and End time when u execute the Master Data Transaction say for eg.BD10 and specify the same in the Time Created input field of BD87,also give the Message Type and the Receiving System Names and execute.
Select the Repective Message Type and Press the Trace IDoc Button.

6. How to trace IDocs based on the data .
Steps:

Execute Transaction WE09
Put in the message type name in the field labeled 'Logical Message' Ex - DEBMAS
Now we will move to the section 'Criteria for Search in Data Records '
In this section we will put the Segment name in which we want to search the existance of data in the field labeled 'Search in Segment' EX - E1KNA1M
In the field labeled 'Search in Field' we will put the field name of the segment in which we want to search the existance of data. Ex - KUNNR for searching IDOCs for certain customer number.
Now in the field labeled 'For Value' we will put the search value. Ex - Customer number as 100 .
We will now execute the transaction.
The result can be a single Idoc or a list of multiple IDOCS depending upon the Search Criteria entered.

7. How to Send and Receive an IDoc in the same system.
Steps :

Create a Dummy Logical System.
- Goto T-Code SALE-> sending and Receiving Systems -> Logical Systems -> New entries.Enter SYSID_CLNT, but this one is Dummy so use the first 2 characters of the SYSID and prefix 'D' then underscore and then the Client number.

- E.g.: If ERP_100 is the logical system of the R/3 then create ERD_100 as the dummy system.
Create Port for the Original System, (ERP_100)
- Goto WE21 and select Transactional Port and press the Create button. Name the Port as "SAP" contatenated with the SYSID in our example it would be SAPERP Select the appropriate version and enter the RFC dest of the system that you are working on in this case it will be 'ERP'.
Create Partner Profile in partner type LS:
- Receiver Side ( Outbound to ) : In Partner type LS name ERD_100create the Outbound Parameters, give the Message type, Receiver Port same as the port we created in step 2. Enter the Basic type.

- Sender Side ( Inbound From ): In partner type LS name ERP_100 create the Inbound Parameters, give the appropriate message type and the process code.
Now create the stand alone program to send the IDoc:
- The program will at some point calls the MASTER_IDOC_DISTRIBUTE function module. When you pass the EDIDC structure it will be populated as follows:
  i_edidc-mestyp = message type.
  i_edidc-idoctp = basic type.
  i_edidc-rcvprt = 'LS'.
  Concatenate 'SAP' sy-sysid into l_port.
  i_edidc-RCVPOR = l_port.
  i_edidc-rcvprn = 'ERD_000'.
  CONCATENATE sy-sysid '_' sy-mandt
  INTO l_sndprn.
  i_edidc-SNDPRN = l_sndprn.
  i_edidc-sndprt = 'LS'.
  i_edidc-sndpor = l_port.
Observe that the Sender port and the receiver port is the same, this does the trick. The outbound Idoc is sent on the port SAPERP with the Sender as ERP_100 and receiver as ERD_100 and then the Inbound Idoc is also sent to the same port SAPERP with the Sender as ERP_100 and receiver as ERD_100.

8. What is message control and when do we use it?
Message control is a mechanism by which documents are output based on a selection criteria and requirements. This concept is applicable not only to EDI and ALE, but also to other output mediums (for example: print, fax). Message control determines the type of document, its timing, number, and the medium. NAST table stores output records. The conditions (selection criteria and requirements) for creating an output message are stored in condition tables. Search mechanisms are used through access sequences, output processes, and requirements to determine whether an application document qualifies for output.
Some of the tables for Message Control are :

Transaction Code	Description
Transaction Code	Description
NACE	Condition Record Maintenance
VOK2	SD Message Control Components
VOK3	Purchasing message Control Components
VOFM	View Message Requirements
V/86	Condition Table Field Catalog
WE15	IDOC test : outbound from Message Control

9. How do you reprocess the failed trfc entries?
You can reprocess the failed trfc entries using the program RSARFCEX.
10. What is the transaction used to find the outbound and inbound process codes at one place?
WE64