When activating a CADDS part with DraftView, I can select the _fd file. Why is that?
DraftView activates CADDS parts in the same manner as CADDS – by opening the _pd file first. This is true, even for 100% parametric parts. For parametric parts, the _pd file contains important data that is used by CADDS and DraftView to parse the _fd file properly. This is why DraftView requires you to select the _pd file in order to activate parametric parts. Recent versions of DraftView allow the selection of _fd files for part activation. This is for convenience only. DraftView actually opens the _pd file first.