They are a pain. Every time I have to get involved with one it is some kind of Lon problem. The book I have is fine if you keep in mind that it assumes that you work for Thyssen and can get factory replacement boards. I usually have to work backwards to figure out what generic files I am missing. One tip is to look for any floor that may have got wet. The Rj45 connectors that daisy chain fixture to fixture corrode easily.
