Beckhoff TwinCAT3 object oriented programming tutorial

I'm new to TwinCAT3 and I've been searching for a tutorial on object-oriented programming. I've seen this link on Beckhoff's Infosys site but was hoping there was something available somewhere with a little more explanation:

https://infosys.beckhoff.com/english.php?content=../content/1033/tc3_sampleprogram1/45035996374683915.html&id=

I'm somewhat familiar with the general concepts from stalled attempts to learn C++ probably in the order of 20 years ago

This is not OOP specific but is the best Beckhoff tutorial out there, in my opinion:
http://www.contactandcoil.com/twincat-3-tutorial/

Thanks, I already have that bookmarked