Introduction to LonWorks Control Network Protocol

Originally developed by Echelon Corporation, LonWorks (Local Operating Network) is a control networking protocol used for the automation of functions within a facility. Manufacturers across myriad industries have adopted this technology as the basis for a variety of applications, such as municipal and highway lighting, heating and air conditioning systems, intelligent electricity metering, subway train control, building lighting, and security systems.

The LonWorks platform is built on the underlying concept that information in sensing, monitoring, and control applications is fundamentally the same across all industries. A second factor in the platform's concept is the knowledge that all networks, whatever their functions, increase in power as nodes are added.

LonWorks networks closely resemble traditional data networks — numerous devices attached to various communications media, all connected by routers that connect with each other using a common protocol. LonWorks networks can range from small, relatively simple networks embedded in machines to expansive networks encompassing thousands of devices.

Our Commitment to LonWorks

Sierra Monitor has been committed to the LonWorks standard since its inception. As one of the first manufacturers of LonWorks gateways and a member of LonMark International and LonMark Americas, we continue to support our customers with ongoing updates to our LonWorks driver and continue to enhance our hardware platforms to take advantage of the latest Free Topology (FT) transceiver technology- the preferred serial link for devices that implement LonWorks.

In addition to being fully compliant with the standards (see below), FieldServer LonWorks protocol gateways are tuned for performance. The FieldServer protocol gateway can interface LonWorks-based devices and networks to over 100 other unique protocols with the largest driver library in the industry. Some unique applications require an external interface file (.XMF), which can be uploaded to the FieldServer. Differing from most LonWorks devices, the .XIF file is not fixed due to varying applications, allowing for maximum connectivity and customization capabilities.

Standards & Certification

LonWorks became and ANSI standard in 1999, and subsequently became a widely adopted global standard. The standard is supported and maintained by LonMark International. Standards include:

  • ANSI/CEA-709.1-B
  • ISO/IEC 14908-1
  • ISO/IEC 14908-2
  • ISO/IEC 14908-3
  • ISO/IEC 14908-4

LonMark International is responsible for certification, education, and promotion of interoperability standards for the benefit of manufacturers, integrators, and end users. LonMark International has developed extensive product certification standards and tests to provide the integrator and user with confidence that products from multiple manufacturers can work together.

Sierra Monitor's FieldServer has more LonMark Certified gateways for integrators and OEMs that carry the LonMark logo than any other gateway manufacturer. For more information about our LonMark Certified products, visit the LonMark International Product Certification Directory.

LonWorks Interoperability

Devices that implement the standard can seamlessly interoperate with each other. However, in complex facilities, it is often necessary to connect a LonWorks-based network of devices to a BACnet/IP based management system. Conversely, it might be required to bring smaller islands of Modbus, M-BUS, or BACnet MS/TP devices into a LonWorks network. A LonWorks device network may also need to communicate to a cloud service over XML or to a systems management platform over SNMP.

The LonMark Certified FieldServer protocol gateways connect LonWorks devices to various management systems, and non-LonWorks devices to LonWorks-based device networks. Integrators and installers use our gateways for their flexibility, reliability, and ease-of-use, while OEMs often incorporate FieldServer protocol gateway technology into their devices in lieu of doing their own protocol development.


FieldServer protocol gateway and router products from Sierra Monitor can connect LonWorks devices to various management systems and non-LonWorks devices to LonWorks management systems. The products are configured with the LonWorks specific hardware and the LonWorks driver along with the other required protocol drivers. Buyers order the LonWorks option on one of the hardware platforms below and specify the other drivers they want loaded on it.

LonWorks Converters and Gateways for Integrators

Integrators value the flexibility and ease-of-use offered by the FieldServer protocol gateways because it allows them to complete their integration projects quickly and with low risk. The following products are available to integrators:

LonWorks Converters and Gateways for OEMs

OEMs embed the FieldServer protocol gateways with their products as it enables them to become “multi-protocol" aware (without increasing R&D costs), so they can bid on different project specifications. The following products are available to OEMs:

Protocol Drivers

LonWorks protocol converters and gateways are ordered with the following protocol driver:

The gateway is also ordered with one or more of the following protocols depending on what other control networks are being connected to the LonWorks network: