How to add additional functions to RS485?

Question

Electronics

Good afternoon. There is a need to get a universal interface that can be used as RS485, ADC and discrete output. For RS485, it is planned to use publicly available chips like MAX485, etc. How realistic is it to hang transistor switches, etc., on outputs A and B of RS485? to get the output and ADC, while retaining at least half of the declared characteristics of RS485? Maybe someone has experience of such perversions. Software switching is planned, without jumpers, etc., during device configuration. The question is posed very vaguely, but I don’t feel like drawing technical specifications here either, I will answer any questions in the discussion process. Thank you very much in advance.

Answer 1

RS485 is not a bus to which different devices can be connected, it is a connection between two devices.
You need to hang the device on some controller, and on it already implement the functions you need, which you will control via RS485. Or run multiple RS485 lines and connect individual devices.

Answer 2

how to invent a bicycle with a tricky gear??
you can cram everything into two pins in an elementary way, in the simplest version, taking a set of analog keys.
for example, 2 sets of one-to-three switches with the appropriate range of operating switching voltages and currents.
but the terms of reference are utterly inaccurate, so you can’t write more. and there are no psychics.
option 2: it's a pity for pins. Krivorukovye bicycles during operation come out in one place.

Answer 3

Hang relays (as an option, small solid-state opto-relays), which inside your device will switch the signal to the 485th transceiver, ADC with a measurement circuit, or to a pair of keys implementing 0-12V discrete outputs. There will be a kind of multiplexer. :)
To preserve the properties of the 485th, cut off all other devices as close as possible to the connector, so that the tails that go nowhere would not hang.