Seismic Loads in PROFIS

In PROFIS, does N imply that it is a vertical direction ?
Under pure seismic I add (-) sign in front of Fy load and get different outcome. How can you explain it ? Aren't seismic loads meant to be reversible?
How can I change the units for input geometry once it's already in ?
This is urgent , please call asap.
Peter K. Ostrowski
647 294 9136