Introduction - If you have any usage issues, please Google them yourself
The ConnectionBase class is a base class for defining connections, details and seams. These types are more specialized and restricted by the input values than the ones derived from PluginBase.
The coordinate system for connections, details and seams is explained in the Tekla Structures help, in the part about the position type of custom components. The position type defines the origin of the custom component, relative to the main part