Bob: You must plug the computer into the KIO2 inside the K2 for it to communicate with the computer. The cable from the K2-KIO2 to the external KPA100/KAT100 combo does not have the connections for TXD abd RXD lines from the control board. These are required for the computer to communicate with the K2 control board. 73 Jim Younce K4ZM K2 SN: 18