Elektor Formant Modular

hi
i just got my first formant system. its very big! theres a picture of
it in the photos section. i'm just getting my head round it and a few
things are puzzeling me
how does the 'adsr controller' module work?
what are the 'ringen' modules for?
my system has no 'com' modules - what are they?
cheers
ben