First connect the USB<>RS232 cable to the PC. Then go to windows control panel > device manger >connections and see which ComPort has been assigned to your CAT cable. Try unplugging the cable and plugging it back in so you are sure you have found the right port. If the assigned ComPort is not to your liking you can change it in the Properties menu. After that you can configure RadioSynch as in the Hardcopy on my PC. If you have further questions, please get in touch. 73 de Arturo, HB9MIR