I have an RF850 and several RF820s connected to the RF850 via IPSEC tunnels. I would like to be alerted when the tunnel from a particular firewall goes down. Is there a way to do this and then to look at a log to see what is happening?

The routefinder does not notify you if the VPN tunnel goes down.

You can use other third party monitor applications that can ping across all the VPN tunnels, and if a VPN tunnel does not responsd back, then the tunnel might be down.