About Separation Measures
A separation measure reports values based on the separation between two points or vertices you select on your mechanism. You can create separation measures of the following types:
Distance—Measure the absolute value of the distance between two selected points in the mechanism.
Speed—Measure the rate of change of the separation distance. This value is positive when the points are moving away from each other and negative when moving toward each other.
Change in speed—Measure the rate of change of the separation speed.