What is ANSI 709?
Up until 1997, the LonTalk protocol was available only embedded in the neuron chip. This guaranteed consistent application by all manufacturers. Once a large number of compliant devices had been installed, however, Echelon Corp. published the LonTalk protocol and made it an open standard.
Its formal name is ANSI/EIA 709.1 Control Networking Standard. The protocol is available to anyone.
Each domain in a system using the LonTalk protocol can have up to 32,385 devices. There can be up to 256 groups in a domain, and each group can have any number of nodes assigned to it, except that when end-to-end acknowledgment is required, groups are limited to 64 nodes. Each node can be a member of up to 15 groups.