Hi Mike,
Thanks. I reread the manual and I guess it does say that but its not easy to understand. Its a shame the USB port can't be used as that is used for local CAT control.
So to recap. I connect my radio base unit CI-V jack to the radio RRC Com2. At the control RRC end I use the USB connection from control RRC to computer. When I connect this I have COM6,7,8,9. I guess I can chose any of these.
QUERY: In the configuration for the control RRC there is a setting that says 'Use USB COM port as COM2'. This would seem to imply I can use the USB connection although I've not tried it.
73 Bob