I have a set-up with 3 raspies (type Pi2B or Pi3B+, here named pi_1, pi_2 and pi_3) like this: pi_1 ethernet connected to pi_3 usb2ethernet adapter, pi_2 ethernet connected ro pi_3 usb2ethernet adapter, pi_3 ethernet connected to the local subnet. They all (pi_1, pi_2 and pi_3) handle I/O signals an...