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Tuesday, July 17, 2007

Useful Guide to ALE, IDOCs

ALE/IDOC

IDOC Programming
There are two processes in IDOC processing one is INBOUND PROCESS( IDOC coming to the system and its handling at various stages) and the other is OUTBOUND PROCESS( IDOC is send to other system . Separate ABAP programs are written for these 2 processes and different configuration settings are required for each one .Depending upon the trigeering mechanism different programming approaches are used.OUTBOUND PROGRAMS handle the IDOC creation and INBOUND PROGRAMS handle the inbound IDOC and the data trasfer from the IDOC to the database tables.

NEED FOR ABAP PROGRAMMING arises if


1)New IDOC was created
Depending upon the triggering mechanism i.e change pointer,message control
etc the programming technique changes and the type of process.
2)Existing IDOC was extended
User Exits are used to populate data in new segments added and to read them
back.
3)To enhance an exsiting process.
User Exits are used .

Basic structure of an OUTBOUND PROGRAM
The basic structure of all outbound programs is same. The CONTROL
record which is of TYPE EDIDC has to be filled. It contains important fields like
IDOCTP IDOC type
MESTYP Message Type
RCVPRN Recieving Partner (Destination)
RCVPRT Partner Type (it is LS i.e Logical System)

The DATA RECORD internal table which is of TYPE EDIDD has to be filled
in the same order as there are segments in the IDOC definition.
It has 2 important fields which are to be filled ,these are

SEGNAM Name of the segment
SEGDATA Data in the segment and can be upto 1000 bytes.This field
is corresponds to each data segment in the IDOC.
e.g.
DATA INT_EDIDD LIKE EDIDD OCCURS 0 WITH HEADER LINE.
DATA W_SEGDATA LIKE zsegment "custom segment zsegment

INT_EDIDD-SEGNAM = 'ZSEGMENT'
W_SEGDATA-field1 = value "taken from some table
W_SEGDATA-field2 = value "taken from some table
INT_EDIDD-SEGDATA = W_SEGDATA
APPEND INT_EDIDD

This will fill the data record corresponding to the segment ZSEGMENT . For all
segments the sam steps will be repeated until all the data corresponding to all the
segments in the idoc is filled in the internal table of type EDIDD.
There is only one control record and can be multile data records in the idoc
structure.

Which data is to be extracted from the tables to be filled in EDIDD type internal table is determined in standalone programs from the objects which are specified in the selection screen and from the object key passed to the function module in case of message control and is taken from BDCP table in case of change pointers using function modules "CHANGE_POINTERS_READ"

In case of stand alone programs and function modules based on change pointers method the function module "MASTER_IDOC_DISTRIBUTE" is used to send the IDOC to ALE layer for distribution ,in case of message control it is handled automatically by the RSNASTED program invoked by the message control.
OUTBOUND PROCESS AND OUTBOUND PROGRAM.

Outbound programs are used in outbound process to genearte IDOCs . There
purpose is to extract the data from the tables and to fill the IDOC data records
and the control record in the IDOC and pass ito the ALE layer for distribution to the recieving system .

Depending upon the triggering mechanism (how and when the outbound program will be started different techniques and interface is used for outbound program.

1)Message control
Application like PO(purchase order) creation use this technique , where the output type is linked to the application(Message control is a configurable cross application component which can be set in IMG .Such programs are created in the form of function modules and linked to the output type which is linked to the apllication.These have predefined interfaces.
In outbound programs(function module) that use message control the key of the
application document is passed to the function module whcig will read the data from the table depending upon the key passed(NAST structure) and fill the IDOC segemnts with the application data.The control record is also passed to the function module but is not fully filled, the rmaining fields are filled and the control is passed back to the calling program which is RSNASTED and is invoked by the
message control to process ALE and EDI output types and this program on recieving the IDOC data will create the physical IDOC in the system.

The parameteers passed to the function module are
IMPORTING PARAMETERS
OBJECT LIKE NAST
It contains documents key.
CONTROL_RECORD_IN LIKE EDIDC
It contains the partailly filled control record
EXPORETING PARAMETER
OBJECT_TYPE
CONTROL_RECORD_OUT LIKE EDIDC
TABLES
INT_EDID LIKE EDIDD
The internal table used to fill the data records in the same order as they exists in the IDOC.

The important parameters that should be filled in the custom function module are
CONTROL_RECORD_OUT and INT_EDIDD .The OBJK field of the structue NAST contains the key of the apllication document.


2)Stand alone programs

Generally used for Master Data transfer and as such depending upon the requirement can have different interfaces.The programs have a selection screen which has select options to select the objects, and parameters for specifying the recipient Logical System and the Message Type.

Data is selected based on the specified objects from the tables . and control record of type EDIDC is created and filled with important values like DIRECTION ,IDOCTP,RCVPRT,RCVPRN and MESTYP .

Data is filled in an internal table of TYPE EDIDD according to segment definitions
and in same order and the function module MASTER_IDOC_DISTRIBUTE is called passing the control record and the internal table containg IDOC data and importing an internal table consisting of control records for each communication IDOCS created.


3)Change pointer

Change Pointer table is read and checked if changes were made to important fields , if so the outbound program will be triggered automatically , these have predefined interfaces


ALE/IDOC Transaction

SALE Area Menu for ALE configurations.It includes transactions for
Logical System definition and linking it to a client, Transactions for
RFC Destination and Port Definition Etc.

SM59 RFC Destination
Here we specify the login settings for the destination including
the I.P address or Application Server name and the User name and
password.The information entered here is used to run Remote Function
Calls(RFC ) on the destination server .We can create number of types
of RFC Destinations but 3 types are important .
R/3 (R/3 to R/3), LS(logical system) and TCP/IP.
The name of the RFC destination should be same as that of Logical
System as it helps in creation of automatic partner profiles.

WE21 Port Definition.
There are 6 types of ports but only 2 types File and Transactional RFC
types of ports are important.
We have to specify the RFC Destination before a port can be created.

WE57 This is used to assign the Inbound function module to the Message Type
and to the IDOC Type.
WE42 This is used to define the process Code for Inbound Processing.

BD95 Define Filter object type .We can specify the field and the table it belongs
to as a filter object .
BD59 Assignment of Filter object type to the Message Type .Here we create the
link between Filter object and the segment and the message type and the
segment Field.
BD50 Set message Type to reducible.
BD65 Define Mandatory Fields.

BD64
Distribution Model . Also known as Customer Distribution Model Used to
define all the messages that will be exchanged between remote systems
and the name of thes logical systems. Any filters can also be specified.
The model once created has to be distributed on every system which will
be communicating ,It can be maintained on only One system.

BD21 Creating IDOcs from change pointers.
This can be used to create IDOCs from change pointers for a particular
message LIKE MATMAS.

BD22 This can be used to delete change pointers.

BD87
Status Monitor. Idocs can be selected base on number of criteria and there
processing status can be seen in detail.


BD10
Material Master Data Distribution .
Based on Message MATMAS.
BD12 Customer Master Data Distribution .
Based on Message CREMAS.
BD14 Vendor Master Data Distribution
Based on Message DEBMAS .

BDFG Generate ALE Interface for BAPI.
Here we specify the Business Object and the BAPI Function module for
which the interface has to be created.
WE31 Segment Editor.
This is used to create segments. We create the segment type and
segment definition is automatically created by editor e.g. Z1DUMMY is
segment type and Z2DUMMY is the segment definition .We specify the
fields and the data elements these cp\orresponds to create segments.

WE30 IDOC Editor
It is used to create a new IDOC Type or IDOC Extension .We specify the
segments that will be addd to the IDOC type.

WE02/05 IDOC List.
Various selct options and parameters are provided to select IDOCs
depending on the date, direction , mesage type etc.

WE20 Partner Profile
Here we create partner profile for each and every partner from / to which
the messages will be exchanged.There are 6 types of PF generally only
profiles of type LS(Logical System) ,KU(Customer) ,LI(Vendor) is used.
We specify the partner number and partner type and the agent and
the agent type responsible for handling of errors .
For every message send to the partner we have a outbound record and for
evry message coming from the partner we have the inbound record .
We specify the message in the otbound/inbound records ,double
clicking will take us to the detailed screen where the IDOC Type ,Port
and whether the IDCO will be immediatelt processed or collected are
mentioned.




IDOC Status Code

Status Description

00 Not used, only R/2
01 IDoc generated
02 Error passing data to port
03 Data passed to port OK
04 Error within control information of EDI subsystem
05 Error during translation
06 Translation OK
07 Error during syntax check
08 Syntax check OK
09 Error during interchange handling
10 Interchange handling OK
11 Error during dispatch
12 Dispatch OK
13 Retransmission OK
14 Interchange Acknowledgement positive
15 Interchange Acknowledgement negative
16 Functional Acknowledgement positive
17 Functional Acknowledgement negative
18 Triggering EDI subsystem OK
19 Data transfer for test OK
20 Error triggering EDI subsystem
21 Error passing data for test
22 Dispatch OK, acknowledgement still due
23 Error during retransmission
24 Control information of EDI subsystem OK
25 Processing despite syntax error (outbound)
26 Error during syntax check of IDoc (outbound)
27 Error in dispatch level (ALE service)
28 Not used
29 Error in ALE service
30 IDoc ready for dispatch (ALE service)
31 Error - no further processing
32 IDoc was edited
33 Original of an IDoc which was edited
34 Error in control record of IDoc
35 IDoc reloaded from archive
36 Electronic signature not performed (timeout)
37 IDoc added incorrectly
38 IDoc archived
39 IDoc is in the target system (ALE service)
40 Application document not created in target system
41 Application document created in target system
42 IDoc was created by test transaction
50 IDoc added
51 Application document not posted
52 Application document not fully posted
53 Application document posted
54 Error during formal application check
55 Formal application check OK
56 IDoc with errors added
57 Test IDoc: Error during application check
58 IDoc copy from R/2 connection
59 Not used
60 Error during syntax check of IDoc (inbound)
61 Processing despite syntax error (inbound)
62 IDoc passed to application
63 Error passing IDoc to application
64 IDoc ready to be transferred to application
65 Error in ALE service
66 IDoc is waiting for predecessor IDoc (serialization)
67 Not used
68 Error - no further processing
69 IDoc was edited
70 Original of an IDoc which was edited
71 IDoc reloaded from archive
72 Not used, only R/2
73 IDoc archived
74 IDoc was created by test transaction




IDOC Function

CALL FUNCTION 'MASTER_IDOC_DISTRIBUTE'
EXPORTING
VALUE(MASTER_IDOC_CONTROL) LIKE EDIDC STRUCTURE EDIDC
" Control record of master IDoc
VALUE(OBJ_TYPE) LIKE SERIAL-OBJ_TYPE DEFAULT ''
VALUE(CHNUM) LIKE SERIAL-CHNUM DEFAULT ''
TABLES
COMMUNICATION_IDOC_CONTROL STRUCTURE EDIDC
" Control records of created comm. IDocs
MASTER_IDOC_DATA STRUCTURE EDIDD
" Data records of master IDoc
EXCEPTIONS
ERROR_IN_IDOC_CONTROL
" Incorrect entry in IDoc control record
ERROR_WRITING_IDOC_STATUS
" Error when writing IDoc status records
ERROR_IN_IDOC_DATA
" Incorrect entry in IDoc data records
SENDING_LOGICAL_SYSTEM_UNKNOWN
" Own logical system unknown

CALL FUNCTION 'CHANGE_POINTERS_READ'
EXPPORTING
VALUE(ACTIVATION_DATE_HIGH) LIKE SY-DATUM DEFAULT SPACE
VALUE(ACTIVATION_DATE_LOW) LIKE SY-DATUM DEFAULT SPACE
VALUE(ACTIVATION_TIME_HIGH) LIKE SY-UZEIT DEFAULT '000000'
VALUE(ACTIVATION_TIME_LOW) LIKE SY-UZEIT DEFAULT '000000'
VALUE(CHANGE_DOCUMENT_OBJECT_CLASS) LIKE CDPOS-OBJECTCLAS
DEFAULT SPACE
VALUE(CREATION_DATE_HIGH) LIKE SY-DATUM DEFAULT SPACE
VALUE(CREATION_DATE_LOW) LIKE SY-DATUM DEFAULT SPACE
VALUE(CREATION_TIME_HIGH) LIKE SY-UZEIT DEFAULT '000000'
VALUE(CREATION_TIME_LOW) LIKE SY-UZEIT DEFAULT '000000'
VALUE(MESSAGE_TYPE) LIKE BDCPS-MESTYPE
VALUE(READ_NOT_PROCESSED_POINTERS) LIKE BDCPS-PROCESS DEFAULT
'X'
TABLES
CHANGE_POINTERS STRUCTURE BDCP
MESSAGE_TYPES STRUCTURE BDMSGTYP OPTIONAL
EXCEPTIONS
ERROR_IN_DATE_INTERVAL
ERROR_IN_TIME_INTERVAL


CALL FUNCTION change_pointers_status_write.
IMPORTING
VALUE(MESSAGE_TYPE) LIKE EDIDC-MESTYP
TABLES
CHANGE_POINTERS_IDENTS STRUCTURE BDICPIDENT

Examples of Inbound function modules are
IDOC_INPUT_BLAOCH IDoc inbound processing: change Ccontract
IDOC_INPUT_BLAORD IDoc inbound processing: Create Contract
IDOC_INPUT_MATMAS01 IDoc inbound processing: Material Master

Examples of Outbound function modules are
IDOC_OUTPUT_BLAOCH
IDOC_OUTPUT_BLAORD

Other USeful Links :

Download IDOC Presentation

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