LonTalk

LonTalk is a network communication protocol used in LonWorks control networks to support distributed control across buildings and industrial facilities. It defines how devices such as sensors, actuators, and controllers exchange information and coordinate actions in real time.

LonTalk is device- and media-independent. It uses a data model based on network variables and datapoint types to describe the data exchanged between devices. Communication is organized around device types described in exchangeable interface files (XIFs), which enable interoperability between devices from different manufacturers. The protocol supports multiple transport layers, including twisted-pair networks (commonly implemented as TP/FT-10 LonWorks), powerline networks, and, in some deployments, IP-based transport, allowing LonWorks devices to operate on various physical media.

LonTalk and the LonWorks platform have been promoted through LonMark International, which certifies device types and interoperability. The LonTalk specifications have been published as standards and vendor implementations provide development tools, software environments, and management utilities. The approach emphasizes distributed intelligence, with no central controller required; devices communicate peer-to-peer through network variables.

Applications: LonTalk is widely used in building automation for HVAC control, lighting, security and access, energy management, and environmental monitoring, as well as in industrial automation and process control. Networks can scale from small installations to large campuses and multi-building facilities, benefiting from a distributed, event-driven architecture and the capacity to integrate devices from multiple manufacturers.