I purchased this system from a company that went out of business. They sold me the system, ten 2000 seris phones and the programming manuals. The system has the TCOU card in it. Everything seems to work fine with all the phones having two CO Line buttons on them. My business has now grown and I would like to utilize more of the phone systems features. The initial setup was easy, but the more advance stuff is puzzling me. The program manuals are to vague.