Definition - What does RS-485 mean?
RS-485 is also known as EIA-485 or TIA-485.
Techopedia explains RS-485
Data transmission rates range from 35 Mbps (up to 33 feet)-100 Kbps (up to 4,000 feet). Because star and ring configurations are not recommended, equipment installed along RS-485 transmission lines (known as nodes, stations or devices) are connected as series. However, if necessary, star or ring configurations may be accommodated with special star/hub repeaters.
RS-485 uses a two-wire twisted pair bus. Although not always required, RS-485, like RS-422, may be configured with four wires as full-duplex. With certain restrictions, RS-422 and RS-485 may be co-configured.
Additionally, the RS-485 specification is used by Small Computer System Interface (SCSI)-2 and SCSI-3. RS-485 also may be used to allow remote connectivity between PCs and remote devices.