The LonTalk Protocol

All LonWorks devices communicate with each other using a standard protocol that's embedded in Neuron Chips found in most every LonWorks device available today. In 1999, Echelon released a downloadable reference implementation of this protocol for use on any processor. This protocol is defined in ANSI-approved standard EIA/CEA-709.1-A-1999. Subsequently, the communications protocol has been accepted as a global standard (ISO/IEC 14908), European standard (EN14908), and Chinese standard (GB/Z 20177.1-2006).

Protocol Reference Implementation

Protocol Specification: EIA/CEA 709.1-B-2002

The current EIA, non-ANSI specification is available for purchase as document EIA/CEA 709.1 through Global Engineering Documents. This document is not available from Echelon.

Questions and Answers About the Protocol Patent License Agreement

What is Echelon’s Protocol Patent License Agreement?

The LonTalk protocol was invented by Echelon and is the subject of numerous patents associated with its innovative features and functions. LonTalk is Echelon's registered tradename for the underlying protocol of the LonWorks platform. It is now known by the numerical designations assigned by standards bodies that have adopted the protocol (see above).

The protocol was designed to enable highly reliable, peer-to-peer as well as hierarchical networking among control devices manufactured by different suppliers. Achieving interoperability among devices required both that the protocol be implemented in an identical manner within all networked devices, and the establishment of a reliable and consistent means of transmitting, broadcasting, and receiving messages between and among LonTalk based devices. The Neuron Chip and Smart Transceiver implementations of the protocol, combined with Echelon’s physical layer transceivers, provide a foundation for interoperability among devices.

When the protocol was published and incorporated into open standards such as the ANSI/CEA-709.1-B-2002 Control Network Protocol Specification, the Protocol Patent License Agreement was created for two purposes: (1) to ensure that anyone who implemented the protocol on a processor other than the Neuron Chip or Smart Transceiver did so in a manner that would be fully interoperable and could not be modified to become non-interoperable; and (2) to allow such an implementation to be accomplished without infringing applicable Echelon protocol patents.

How does Echelon ensure that the terms of the Protocol Patent License Agreement are followed?

Echelon conducts random tests of devices that incorporate the licensed protocol. In addition, we investigate any reported device problems or behavior believed to be associated with an improper implementation of the protocol.

What happens if the protocol is not fully implemented by a licensee?

The Protocol Patent License Agreement mandates that the protocol be fully implemented without exception. Full implementation of the protocol is mandatory to ensure interoperability between devices. Partial protocol implementations, user-modifiable protocol implementations, and deviations from the protocol specification jeopardize interoperability and accordingly are explicitly prohibited and constitute grounds for termination of the Agreement. The Agreement clearly specifies remedies in the event of non-compliance.