Setup for Nikon DTM-450

I'm setting up a new (used) Nikon DTM-450 with Carlson SurvCE 2.58 for the first time. Not going so well. Need help, please. I contacted tech support at Carlson and I was advised to follow Topic 828. I followed this set of instructions carefully, and many other test configurations, but I have been unable to establish communication between TS and DC.