Rand Mcnally gps rv7720 turn announcement update

When you get to the screen with the bar graphs, click on help. It tells a little but not much.
Like you said there is not much for help.
Have you downloaded the manual?
Manual
From manual
Set three distances at which you want
to be warned about an upcoming turn.
The first announcement will be the farthest
from the turn and the third the closest to it.