I’m with Mono on this. As a simple avionics man I can't believe I'm reading this.
For the system to tell you what you want to know - you need to first tell it what you want to know. You do this by positiong the course arrow. Note the word ‘selected’ below.
The To-From arrows indicate whether the selected course is going toward or away from the selected beacon station. The course deviation dots indicate course deviation in degrees relative to the course deviation bar position. The COURSE SET knob allows the operator to set both the course arrow to a desired course and the COURSE indicator to the desired course readout when in any mode other than TAC NAV.
See
http://www.professionalpilot.ca/help/tuning_help.htm