... RS119 Series converter is equipped with a multiple interface circuit that can handle RS-232, or RS-422/485 serial interfaces ... interface (RS232/485/422)4.Multi-mode 2KM, signal-mode 20KMCommunication Standard Accord EIA RS-232, RS-485, RS-422 standard RS-232 signal IN, OUT, GND RS-485 ... mode 20KM Loading RS-485/422 port Support 32 port loop enviroment(or handtailor 128 point) Interface protection 600W ...