Richard, it's not in the documentation. However, I tried it this morning and it works fine. Go to System Setup/ARINC when you power up your system. Then scroll all the way to the bottom option on that screen. It says "Tie HSI and Flight plan sources together". The option is just "YES or NO". Select yes and all done. Tried putting two different plans in - one in SV, and the other in my 430W. By going to the PFD page and hitting the "HSI Source" button, it flips between your possible sources and changes the depicted route on the map. Very slick. I like it.