Internal tables can only be converted into other internal tables. You cannot convert them into structures or elementary fields.
Internal tables are convertible if their line types are convertible. The convertibility of internal tables does not depend on the number of lines.
Conversion rules for internal tables:
· Internal tables which have internal tables as their line type are convertible if the internal tables which define the line types are convertible.
· Internal tables which have line types that are structures with internal tables as components are convertible according to the conversion rules for structures if the structures are compatible.