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, the IDoc type. For example, the FIDCMT message type is used for journal messages.
The IDoc type indicates the SAP format that is to be used to interpret the data of a business transaction.
An IDoc type consists of the following components:
· a control record
This is identical for each IDoc type.
· several data records
One data record consists of a fixed key part and a variable data part. The data part is interpreted using segments, which differ depending on the IDoc type selected.
· several status records
These are identical for each IDoc type and describe the statuses an IDoc has already passed through or the status an IDoc has attained.
Function Modules Locate the document in its SAP Library structure
Function modules are procedures that are defined in special ABAP programs only, so-called function groups, but can be called from all ABAP programs. Function groups act as containers for function modules that logically belong together. You create function groups and function modules in the ABAP Workbench using the Structure linkFunction Builder.
Function modules allow you to encapsulate and reuse global functions in the SAP System. They are managed in a central function library. The SAP System contains several predefined functions modules that can be called from any ABAP program. Function modules also play an important role during updating and in interaction between different SAP systems, or between SAP systems and remote systems through remote communications.
Unlike subroutines, you do not define function modules in the source code of your program. Instead, you use the Structure linkFunction Builder. The actual ABAP interface definition remains hidden from the programmer. You can define the input parameters of a function module as optional. You can also assign default values to them. Function modules also support exception handling. This allows you to catch certain errors while the function module is running. You can test function modules without having to include them in a program using the Structure linkFunction Builder.
The Structure linkFunction Builder also has a release process for function modules. This ensures that incompatible changes cannot be made to any function modules that have already been released. This applies particularly to the interface. Programs that use a released function module will not cease to work if the function module is changed.
Function Groups
Creating Function Modules
Segment Type and Segment Definition Locate the document in its SAP Library structure
Definition
Segments form the basic building blocks of an IDoc type and are used to store the actual data.
A segment type is the name of a segment and is independent of the SAP release.
The segment definition is the release-specific name of a segment. By combining the segment type and the release, the required segment definition can be determined: This way, you can assign segment definitions from previous releases to an IDoc type in the current release. This may be necessary if, for example, the partner is using an older release which supports your current IDoc type but not your current segment definitions. You then have to "reset" these in the Partner profiles .
The segment definition is also the external name of the segment that the partner system "sees".
Caution
Do not transfer the meaning of these terms to IDoc types: Therefore, an IDoc type ("an IDoc is an IDoc type filled with data") is always data-independent, while a segment type is always release-independent. A segment can be part of both an IDoc (data-dependent) and an IDoc type (data-independent).
Leaving content frame
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.