I installed the Echo to replace the NavWorx, which was wired into my 5600. I used the the existing wiring and the Echo "worked" right out of the box. However, I'm not sure the 5600 is parsing the relative altitude information correctly as the 5600 displays the traffic's relative altitude as 3 digits with no decimal point. I have only flown once with the Echo and haven't had access to the plane since. I hope to fly this weekend and will try to get a better handle on the indication.
Please report back on the altitude issue ---- my hangar neighbor, and I, 5500T and 5600T Navworx, are considering the Echo, also.
Ron