chuck les

The book is fine, and what you would expect for a standards reference manual (mostly). My problem with it is the fact that LON is a data communications network, as such it should use twisted pair. This book says as much. It also says, in a footnote on page 7-7, that a specific cable that is not twisted pair (simply 2 conductor) is approved and is suitable for use in "aggressive eviroments". It does not define "aggressive enviroments" which leaves it open to interpretation and really leaves the door open for any 2 conductor wire in any enviroment to be used as the entire bus. If you have a LON bus that is unreliable, check the bus wire. Is it 2 conductor and not twisted pair? That is probably the problem. Want to have the installing contractor fix it? Good luck! They can make a strong case that Echelon approves of 2 conductor for LON bus. BACnet does not have this problem.