I'll try to note all the circumstances next time it happens to me:

o what's the temperature like
o how long since startup did it happen
o what's the power source for the ZAON and the GPS
o any vibration, maneuvering, etc. going on
o associated with radio transmissions?
o was it aquiring traffic at the time - or was there nothing around

One thing we don't know is how long a data interruption the Garmin GPS will tolerate before
reporting Traffic Unavailable. Is it allowing one second? 5 milliseconds?

In my case, every time I've gone to the TIS setup screen on the Garmin after receiving the lost
data alert, the screen reports Data Available. So this is a transient for me - the data isn't lost for long.

Do you suppose this is a case where Garmin's tolerances are too tight for the ZAON? And it's false alarming very brief data interruptions?

I wish I had the ability to fly a serial line analyzer in my plane connected to this system and recording. Then maybe I could report how long the dropped data incident is. But of course, when
we do something like that the problem never happens. I suspect the "watched pot" syndrome is one reason ZAON's having trouble finding this.