I've got an older RAD left over from a pervious 616 system. I've got the NRU 10, can I use this to hook into the MICS (6.1 Non XC)? I plugged it into a station port on the MICS and I can access the RAD from any set. But I get errors when trying to connect thru PC. Do I need a FastRAD to use NRU 10?