ATEN IC485SN RS-232 to RS-485/RS-422 Bidirectional Converter Specifications: Connectors: 1 DB-25 Female, RS-485 / RS-422 Four Terminal Block, RJ11 Data Rate: Up to 100 Kbps under 4000ft. Function Switches: SW1(DCE, DTE), SW2(TxON, RxON,TxRTS, RxON,TxDTR/RTS, RxDSR/ON)