Hello Dave (feels a bit strange writing that after having watched the movie 2001 recently
From the document CoDeSys Control V3 Manual (Version 14.0):
"In CoDeSys 3.x we no longer distinguish between internal and external libraries. Each library can contain functions and blocks that are either implemented internally (in IEC) or externally (in ANSI-C or C++). External implementation is based on a component of the runtime system, internal implementation is based directly on the CoDeSys library."
This document is available in the customer area http://3s-software.com/index.shtml?en_Down2