4-port RS485 HUB with 2000V optoisolation for RS-485 system in complicated electromagnetic environment. It supports a transmission rate up to 115.2KBPS, and adopts two-way transparent transmission, which allows one RS-485 bus or one RS-232 bus to be divided into 4 RS-485 buses, or any divided RS-485 signal to be transparently transmitted to host computer RS-485 or RS-232 hub. Each RS-485 port of slave computer is provided with reverse connection ..