The USB-COMi+ is one Port RS-232/422/485 USB-to-Serial Adapter, with Easy Mode Setting by Hidden DIP Switch Adds one RS-232, RS-422 or RS-485 serial port by connecting to a USB port One DB9 male connector. There is no need to open chassis to set operation modes as upper case can be sliding open for easy RS-232, RS-422, RS-485 mode. The unit supports: Full RS-232 modem control signals and hardware/software flow control; RS-422 : RS-485 4-wire and RS-485 2-wire: As well units is equipped with automatic transmit and receive control for 2-wire RS-485 half-duplex mode and built-in termination and biasing. For more details on product, Please refer to http://www.papyrus.co.il/1-port_rs-232_422_485_usb-to-serial_adapter_dip.htm