I have a customer that has a DK 16E with an expansion cabinate on the side with a KCDU in it. There a KSTU in the base. It is now set up for 6 CO lines 4 anolog stations and 12 digital station. Can I add a second KCDU in the exp. cab. to give me a total of 16 digital and 8 CO lines and 4 anolog. Thanks for your help