Just a word of caution.
Please don't interpret TCAS as if it were Radar. You are not looking at relative positions of traffic you are observing a "time plot".
There have been a number of serious airmisses ( I think of France in particular and Area Crossing Tracks ) where crews have looked at the TCAS thought they were on a collison course ( which they weren't ) and then turned to make matters worse.
Let TCAS tell you when there's a problem.