When IDoc files are sent to an SAP system, they must be well-formed and they must include a number of mandatory field values.
You can either provide these values explicitly using mapping value expressions, or you can let Talend Data Mapper generate the values for you when it outputs an IDoc file.
The following tables show the fields that Talend Data Mapper can populate for you if you do not specify a value expression yourself, and provide rules showing how the value is obtained. In most cases the values come from context parameters set in the Studio or from the IDocs representation properties.
For information on how to set context parameters, see Talend Studio User Guide.