18.4 LON communication protocol18.4.1 FunctionalityAn optical network can be used within the substation automation system. This enablescommunication with the IED through the LON bus from the operator’s workplace,from the control center and also from other terminals.LON communication protocol is specified in LonTalkProtocol Specification Version3 from Echelon Corporation and is designed for communication in control networks.These networks are characterized by high speed for data transfer, short messages (fewbytes), peer-to-peer communication, multiple communication media, lowmaintenance, multivendor equipment, and low support costs. LonTalk supports theneeds of applications that cover a range of requirements. The protocol follows thereference model for open system interconnection (OSI) designed by the InternationalStandardization Organization (ISO).In this document the most common addresses for commands and events are available.For other addresses, refer to section "".It is assumed that the reader is familiar with LON communication protocol in general.18.4.2 SettingsTable 735:HORZCOMM Non group settings (basic)Name Values (Range) Unit Step Default DescriptionOperation OffOn- - Off OperationTable 736:ADE Non group settings (basic)Name Values (Range) Unit Step Default DescriptionOperation OffOn- - Off OperationTimerClass SlowNormalFast- - Slow Timer classTimeDomain Local without DSTLocal with DST- - Local with DST Time domain18.4.3 Operation principleThe speed of the network depends on the medium and transceiver design. Withprotection and control devices, fibre optic media is used, which enables the use of themaximum speed of 1.25 Mbits/s. The protocol is a peer-to-peer protocol where all thedevices connected to the network can communicate with each other. The own subnetSection 18 1MRK502052-UEN BStation communication1002Technical manual
