An anchored dimension parameter is one which extends from a fixed point, the anchor point, to a adjustable point set. It is comprised of three things: the anchor point, the reference point and the adjustable point set. An example is shown below followed by an explanation of each term.
Anchor Point: The fixed starting point for the dimension parameter. When the value of the dimension parameter changes, this point does not move.
Reference Point: The first point in the adjustable point set. The distance from the anchor point to the reference point is the
value of the dimension parameter. When the value of the dimension parameter is changed, the anchor point retains the same position, but the reference point moves to a new position.
Adjustable Point Set: One or more points that move when the value of the dimension parameter changes. The adjustable point set includes the reference point, plus any additional points which move when the value of the dimension parameter is varied.
To create an anchored dimension parameter, select Insert - Dimension Parameter - Anchored, which opens an assistant to guide you through the process.
Note that the status bar displays a message detailing each step as you are adding the dimension parameter as well as pop-up hints.
Tip: Double clicking on a dimension parameter in your circuit opens up the Parameters Properties dialog box in which you can easily change the name or nominal value.