RS-485 is also known as TIA-485-A, ANSI/TIA/EIA-485 or TIA/EIA-485.
RS485 is a standard that defines the electrical characteristics of drivers and receivers in balanced digital multipoint systems, as defined by the Telecommunications Industry Association and the Electronic Industries Alliance. Digital communication networks using this standard are able to transmit signals efficiently over long distances and in electrically noisy environments.RS-485 makes it possible to connect local networks as well as configurations of multi-branch communication links.
RS485 has two-wire and four-wire wiring, four-wire system can only realize the point-to-point communication mode, now rarely used, mostly used two-wire wiring, this wiring for the bus topology, in the same bus can be connected to a maximum of 32 nodes