" Detect conversion Exit
DESCRIBE FIELD <l_dest> EDIT MASK ls_field_func->fm.
...

      IF ls_field_func->fm IS INITIAL.
        CASE ls_field_func->gen_type.
          WHEN c_gen_number.
            REPLACE FIRST OCCURRENCE OF ',' IN l_input WITH '.'.
            CONDENSE l_input NO-GAPS.
            <l_dest> = l_input.

          WHEN c_gen_time.
            CONCATENATE l_input+0(2) l_input+3(2) l_input+6(2) INTO <l_dest>.

          WHEN c_gen_date.
            CALL FUNCTION 'CONVERT_DATE_TO_INTERNAL'
              EXPORTING
                date_external = l_input
              IMPORTING
                date_internal = <l_dest>
              EXCEPTIONS
                OTHERS        = 1.
            raise_event_conversion_error.

          WHEN OTHERS.
            <l_dest> = l_input.

        ENDCASE.
      ELSE.
        " Try to convert
        CALL FUNCTION ls_field_func->fm
          EXPORTING
            input  = l_input
          IMPORTING
            output = <l_dest>
          EXCEPTIONS
            OTHERS = 1.
        raise_event_conversion_error.
      ENDIF.
    ENDLOOP.