This article will help you understand the basics of ALE and IDocs via a simple do-it-yourself example. We will create a custom IDoc in one SAP system and then post some business data through it to another SAP system. Business data will be picked up from custom data dictionary tables.
ALE – Application Link Enabling is a mechanism by which SAP systems communicate with each other and with non-SAP EDI subsystems. Thus it helps integration of distributed systems. It supports fail-safe delivery which implies that sender system does not have to worry about message not reaching the source due to unavoidable situations. ALE can be used for migration and maintenance of master data as well as for exchanging transactional data.
The messages that are exchanged are in the form of IDocs or Intermediate Documents. IDocs act like a container or envelope for the application data. An IDOC is created as a result of execution of an Outbound ALE. In an Inbound ALE an IDOC serves as an input to create application document. In the SAP system IDocs are stored in the database tables. They can be used for SAP to SAP and SAP to non-SAP process communication as long as the participating processes can understand the syntax and semantics of the data. Complete documentation on IDOC is obtained by using transaction WE60.
Every IDoc has exactly one control record along with a number of data records and status records. Control record has the details of sender/receiver and other control information. Data records contain the actual business data to be exchanged while the status records are attached to IDoc throughout the process as the IDoc moves from one step to other.
Now, let us understand the ALE Configuration by means of an example scenario below:
The Scenario
Data from custom tables (created in customer namespace) is to be formatted into an IDoc and sent from one SAP R/3 system to another using ALE service. We need to have two instances of SAP R/3 systems or we can simulate this on two clients of the same SAP R/3 system.
Create three tables as shown below.
Creating Custom IDoc type and Message type
All the objects created should be present on both source as well as target system(s).
1. Create segments – Transaction WE31
- Create a segment ZRZSEG1
- Add all fields of table ZCUSTOMERS to it
- Save the segment and go back
- Release it using the menu path Edit -> Set Release
- Similarly create two more segments given below
- Seg. ZRZSEG2 – to hold all fields of table ZSOHEADERS
- Seg. ZRZSEG3 – to hold all fields of table ZSOITEMS
2. Create Basic IDoc type – Transaction WE30
- Create a Basic type ZRZORDER
- Add the created segments in the hierarchy shown
- Maintain attributes for each of the segments
- Save the object and go back
- Release the object using the menu path Edit -> Set Release
3. Create/Assign Message type – Transactions WE81/WE82
- Go to WE81
- Create a new Message type ZRZSO_MT
- Save the object
- Go to WE82 and create new entry
- Assign the message type ZRZSO_MT to the basic type ZRZORDER
- Also specify the Release Version
- Save the object
Thus we have defined the IDoc structure which will hold the data to be transferred. In the next part of the article we will understand the outbound settings, i.e. the settings to be done in the source system.
About 
Hi Riyaz,
Appreciate your time for the well explained ALE and IDOC process.
I had quick question about the ongoing issue with the two idoc generation for the same message type.
Created a new ZBA0 copying the BA00.
Maintained the condition records for medium 6.
when i check the processing log at the order it shows only one idoc#. where as in we05 i see the two idocs for the same Sales Order# and status 30.
if i manually add output type with the medium6 it generates only 1 idoc with a status 03
in fact did try to search for the solution over the web and try deleting the condition record.
can you please help and make me understand the reason why it is doing so.
Thank you
Sam
Hi Riaz
Your site is truely great for newbes like myself, thank you.
Please could you help with following error?
With reference to the tutorial , I have the following in WE20 already saved
Partner number: Yes
Partner type LS
Partner role LS
Message type : ZRZSO_MT
Receiver port : Yes
Packet size : 5
Basic type : ZRZORDER
Cancel processing \after sysntax error = X
However WE02 shows status 29 (Entry in outbound table not found
, pointing to table EDP13.) and 01 (IDOC generated) But there are entries in EDP13.
When I simulate with WE19, I get message :
IDoc saved but can not be or should not be sent
Also there is status 37 (Entry in outbound table not found) but the traffic light is green. I also get status 42.
Thanks in advance, I really appreciate your help
Anton
Hi Riyaz,
When iam trying to process the output type at header level iam getting the belwo error.
“Field DIRECT in control is ‘ ‘ which is invalid”
Can u plz help me out.
Very nice…………… thanks for your precious post…please keep posting