When selecing this option, a 6 Foot Sub-D serial port cable (CAB3S6FT) is included. The one side of this cable connects to a 3 pin serial connector on certian MicroX Main boards (SBC boards). The other side will connect to the male Sub-D communication port (DTE) of a target device, like a personal computer. It can for example be used to enable a MicroX Main Board to communicate with a personal computer. When connected to a MicroX Main Board, the following signals will be present on the Sub-D female connector. Pin 2 - Transmit data (RS232 levels) Pin 3 - Receive data (RS232 levels) Pin 5 - Ground The picture below shows the CAB3S6FT cable connected to a SBC45EC Single Board Computer. Note, this option is ONLY for the cable.