Convert RS232 into RS485 signal, Port-powered, Support 2500V isolation, no power supply ... and play, small volume, easy installation 2, Port-powered, high efficiency obtain electricity, can also worked on 3 ... 232, RS-485 standard RS-232 signal TX , RX, GND RS-485 signal D+, D-, GND Asynchronism, ... Relative humidity 5% to 95% Input powered: No power supply needed, powered from TXD, RTS, DTR signal in ...