Thank you Andy,

What you show in the first picture is what I have actually done with success...I would call it 'active'

What I am searching for is the second, where I would ''listen'' to what the ind. contoller sends back to the master. In this case my 89C4051 is'passive'(no TX action) only UAR as you call it.
What did you mean by ...unlimited number of UARTs...?
would you suggest to use two processors : one to detect the correct mnemonic(EMTP) and the other keeping the same data and extracting what I need for further processing.Both processors with RX in parallel.
it is a realtime job...interesting data come with 1 second interval ; so there is enough time for further processing.

ED