In article Pe%vk.431$Dj1.271@trnddc02, "Mike" wrote:

I'm not sure what "system" or "field" you're referring. The computers at
the centers and tracons have no idea if the transponder is ModeS or not.
They only process the beacon code and display the ACID that's in the flight
plan.

The centers and tracons don't have Mode S radars yet?

--
Bob Noel
(goodness, please trim replies!!!)