Have you programed the ports on the DSU for the ATI-D? You can test communications to the ATI-D with a butt set or a slt set. 9600 is the baud rate that is recommended. You can default the debut thru a phone but it would be easier using Keylink. There is also some programming that needs to be done on the DSU to integrate it serially. What software level is the DSU? Mark or one of the other mods can tell you what level that has to be.