Sorry for bad english, so i'll try formally
1. go to views, create new view consist articles without page and block
2. add feed, format is RSS Feed, show Fields
3. add fields:
Content: Title
Content: Body
Content: Authored by
Content: Authored on
Content: Path
4. assign fields at show settings, title to title, body to description, path to link, etc
5. add path at feed settings, for ex. /test.xml
6. save view
try to open example.com/test.xml show error, something about "Error, try later"
Reports record: