Company recently purchased a hotel that has an OPT 51C with Mer Mail. The problem is that the interface to the property management system doesn't work. Chased the cable back to the opt 51 and it is plugged into a serial port. I can't find it programmed anywhere. None of the tty ports are labeled as a pm interface. All the tty ports that show in ld 22 are accounted for. It appears that it is not set up at all. Where do I start? Any help would be appreciated.