the part i do not get it is that how do you know they understand ascii or binary or english?

all human techonolgy... probably they will not understand any message that being sent , plus probably they dont have the same technology as ours to catch these signals.(im not saying they have less technology, it just may not be the same technology.)

You know they could be sending messages, and we may not be understanding them because we dont see the things the way they do.