How to get a hundred serial interfaces on Linux?

Question

linux

Greetings!
There is a need to organize on a device with Linux (from RP to a full-fledged server) the ability to connect several hundred serial (serial) interfaces.
You can connect several interfaces, for example, via a USB hub and several devices based on PL2303. But when the question concerns tens and hundreds, you most likely won’t be able to find anything ready, and you will have to fence something of your own.
Can you please tell me which direction to go in?
1. Do something different. How much labor will it be, taking into account the availability of the element base in China and free electronics freelancers? How reliable is it, given mutual interference? Will the USB bus be enough to route so many USB endpoints?
2. Take something ready. I couldn't find it right away, can someone tell me something?
3. Hybrid option - take something ready-made as a prototype and scale it up to the required amount.
Of course, no serious production is planned, everything is for our own needs. The total number of copies - no more than 5 (excluding test prototypes).

Answer 1

theoretically 128 devices on one usb software port in total with connecting hubs, back to back we can suffice.
collect the power lines from the usb into a bundle and shove it into the power supply.
in theory, you can branch 232, but you need addressing support in the protocol.
with addressing it is possible and 485 to connect everything.
Describe in a bit more detail what you want.

Answer 2

USB is not enough. I think it's better to take a few PasberryPi and get ports for the grid. In general, the presence of so many serial ports is an architectural circuitry error (sane developers do not do this).

Answer 3

FPGA with yusb, which will be brought transceivers?
She will be able to grind many interfaces at the same time and the result is already shoved into USB.
Power transceivers most likely makes sense to start external.