Your needs look very much like I have used much. It is a communication bus, RS485, where the processor is Master and all other devices are Slaves. All Slaves have own addresses (e.g. from 1 to 63 and 0 as a broadcast address - common to all). The Master addresses always one Slave, and only that Slave is allowed to answer, so, there is never a conflict on the bus. If a broadcast message was sent, no Slave unit answers. A very often used communication protocol is MODBUS, you could find and read about it.

Of course, this means that Slaves must be able to communicate fully.

Regards, Slobodan