[KNX] What is the difference between KNX1, KNX2 and KNX3? Only KNX2 is available and recommended for new designs. KNX1 is obsolete, and KNX3 is a future product. Last Update: August 8, 2017 January 11, 2017 1233 KNX Q&A Related Knowledge Base Posts -[KNX] As I can see the RC232-CCT is not suitable for KNX2-demo kit because the .RMD file is missing. As well as the RC232-SA.[KNX] What is KNX?[KNX] 1- What frequencies you are using?