This section explains LonWorks.


LonWorks® is an open network developed by an American company, Echelon Corporation. Echelon Corporation offers free licenses as an open system, so many manufacturers have developed compatible devices. Now, it is managed by LonMark Interoperability Association. LonWorks is commonly used for building automation.

Wiring Method and Communication Protocol

Wiring method

Compatible communication cables include twisted pair cables, coaxial cables, and optical fiber cables. The specifications, such as the communication speed, differ according to the transceivers being used. The supported communication speeds range from 5 kbps to 1.25 Mbps. Basically, a bus is used to connect up to 64 nodes. Star and loop topologies can also be supported when specific transceivers are used. All device transceivers used in a network need to be the same type.

Communication protocol

LonTalk® is used as the communication protocol. This protocol uses a combination of sensors and other devices that incorporate a special chip called the Neuron chip. Devices with neuron IDs communicate with each other using the command/response method. The Neuron chip has a function to prevent data collision. Specifications of the Neuron chip are publicly available, allowing manufacturers to develop compatible devices.


LonWorks® sends and receives data using the command/response method. Responses are made to commands, not via a master, which allows for communication between devices at arbitrary timing.

  • Company, product, and network names mentioned on this page are either trademarks or registered trademarks of their respective companies.
  • Note that some information, such as applicable standards and specifications, may have changed since this page was published.

November 2015

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