RS-422 e RS-485 RS-422 (EIA-422, TIA-422) Differential point-to-point communication (4 wires) Voltage: +/- 5V (from 2V up to 10V), 4kOhm load on RX side Up to 10 receivers for each transmitter 100kb over 1200m, 10Mb over 12 m RS-485 (EIA-485, TIA-485) Multi-point differential communication (2 wires) A single transmitter at a time Differential signalling (1.5V to 5V) Up to 32 devices on each bus 100kb su 1200m, 10Mb su 12m This 485 variant is the most used industrially If you connect to a UART, you use RTS or CTS or a GPIO There are external transceivers Some UARTS have internal RS485 support The TX-off timing is a critical factor