SMAKN&reg; USB 2.0 to Rs-422/rs485 Converter Adapter Serial Win7 64 Mac Pl-2303 Allows to connect RS-485/RS-422 device to your computer by USB port. Real USB 2.0 specification compliant for faster and steadier data communication. TIA/EIA RS-485/RS-422 standard compliant. Data transfer rate up to 230kbps Transmit distance reach up to 1800m at the rate of 9.6kbps. (The longer distance, the lower rate.)