... 2500V isolation, no power supply needed 4, Automatic send data control, auto distinguish and sense ... zero delay automatic transmit Support EIA RS-232, RS-485 standard RS-232 signal TX , RX, GND RS-485 signal ... D+, D-, GND Asynchronism, point to point or multi point,2 wire half-duplex Automatic ... powered from TXD, RTS, DTR signal in RS-232 port Consumption: Static consumption less than 20mA ...