Telemetry with a Devo 10 for a Naza F450

[F450]

Anyone know how to setup telemetry on a Devo 10 for a Naza F450. I've been reading the manual, but can't figure this out. If someone can make a youtube video on how to do this, it would be much appreciated. I just want to be able to have the Devo vibrate once the lipo runs low.

 

[F450]

Here is a pic of of part of the instruction manual:
View attachment 6577

I'm assuming that the External V1 is my main battery, but its say that the Internal 5V is the Power Feeding Voltage. What does this mean?

Here's the link to download the full manual: http://www.walkera.com/en1/fileDown.jsp?file=/cn/upload/explain/DEVO_10_expe.pdf&la=en