Renesas has confirmed the end of LON components[1]. For any owner of a commercial portfolio whose controllers run on LonWorks, the question is no longer theoretical. LonWorks technology relies on the LonTalk protocol and a fieldbus whose supply chain is drying up. This article sets out a factual timeline, the concrete risks for your BMS and a comparison of migration scenarios - before you sign a quotation.
LonWorks in the commercial BMS: the protocol and the risks of its obsolescence
What are LonWorks and the LonTalk protocol?
LonWorks - short for Local Operating Network - is a fieldbus architecture designed for distributed automation in buildings. The LonTalk protocol, standardised as ISO/IEC 14908, handles communication between every node on the network (source: ISO/IEC 14908 standard, lonmark.fr). Each controller carries its own processing interface: the intelligence is distributed, not centralised. For a detailed comparison with the other BMS protocols: BACnet, Modbus, KNX, see our separate article.
Who invented LonWorks and why did LON dominate the 2000s?
Echelon Corporation created LonWorks in the early 1990s. The Neuron Chip, a proprietary chip designed with Motorola, built the LonTalk protocol directly into the silicon of every node (source: lonmark.fr). This distributed automation won over BMS integrators: each system worked without depending on a central supervisor. Ranges such as TAC Xenta, the most widespread LON installed base (Schneider), Sauter and Honeywell have equipped thousands of commercial buildings worldwide.
LonWorks in the commercial BMS: what role in HVAC and control?
Diagram of a typical LonWorks architecture
Click each component to understand its role and status
The LonWorks architecture is built on 3 hierarchical layers communicating via the LonTalk protocol over a TP/FT-10 bus. Here are the typical components of a commercial building still running LonWorks.
Click a component to display its characteristics
Sources: ISO 14908 standard (LonWorks/LonTalk), Echelon/Adesto/Renesas documentation, ASHRAE Guideline 13-2015 (BMS systems)
In a commercial building, LON controllers regulate the water loops for heating and chilled water, control the AHUs and manage lighting or metering. The fieldbus network links the zone controllers to the supervision via LON routers. This scope covers the building management addressed by the BMS classes and standard 52120 (in French). The LON-based commercial BMS remains functional on hundreds of sites - as long as the supply chain holds.
Growing scarcity of spare parts and compatible controllers
LON controllers are leaving the catalogues of the legacy manufacturers one by one: Distech discontinued its ECL range in 2025 and the Schneider TAC Xenta range is discontinued. When a manufacturer stops producing a module, the secondary market (second-hand, clearance stock) becomes the only source. Integrators report lead times of 6 to 12 months for some LON equipment (integrator field feedback). Spare parts are getting scarcer. The owner who waits for a failure before ordering discovers that their end-of-life products no longer have a reliable source of supply.
Loss of integrator skills on the LON protocol
The number of LON integrators able to program and maintain a LonWorks network falls every year. The end of technical support from development tool vendors speeds up this erosion. Commissioning and troubleshooting services rely on a pool of LON skills that is disappearing. The result: dependence on a single contractor, identified as one of the 8 recurring failures in our advisory assignments. Ranges such as Distech ECL, the LON generation, illustrate this concentration of know-how.
Did you know? In the field, LonTalk training courses have become rare and the trained integrators are retiring. A LON network with no competent integrator nearby becomes an operational risk for the owner. Getting a breakdown dealt with can take weeks of searching for a contractor.
Security and compliance risks on an unsupported protocol
A protocol without security patches exposes the BMS to vulnerabilities that stay unfixed. End of support (EOS) means that no patch will close a flaw discovered after standard support has stopped. The risk variable grows over time. For a network connected to IP supervision, the absence of updates opens a breach in the building's security. Regulatory compliance is also in question: can a system without manufacturer support guarantee that the required functions are maintained?
Is a LonWorks network still compatible with the French BACS decree?
The French BACS decree covers control functions and consumption monitoring, not the communication protocol (source: Légifrance, décret n° 2020-887). A working LON network can therefore be compliant. The risk is indirect: if the system fails and parts are no longer available, compliance is compromised de facto. The life cycle of the protocol becomes a parameter of the building's compliance cycle. For the French BACS decree deadlines (in French), see our dedicated analysis.
LonWorks end-of-life timeline: from Echelon to the Renesas announcement
Echelon Corporation creates LonWorks and the Neuron Chip
Standardised as ANSI/EIA-709.1 (1999), then ISO/IEC 14908 (2008). Thousands of commercial buildings are fitted with LON controllers. Your LON estate probably dates from this wave.
End of the original Neuron 3120/3150
Succeeded by the FT 5000 and then FT 6050 chips. The oldest controllers (pre-2010) lose their source of new parts.
Adesto Technologies acquires Echelon ($45m)
The LonWorks intellectual property leaves the world of building automation. The future of the protocol depends on a player from outside the sector.
Renesas acquires Dialog Semiconductor ($5.9bn), which had absorbed Adesto in 2020
LonWorks is now a marginal line at a semiconductor manufacturer. The life cycle enters its decline phase.
Renesas confirms the end of LON components
The FT 5000 and FT 6050 chips will no longer be manufactured. Once stocks run out, no new chip will be available.
Sources: lonmark.org (LonWorks Technology Transition FAQ, July 2025)[1], Adesto/Dialog/Renesas press releases, Reuters
Echelon Corporation: birth and peak of the Neuron Chip
The 1990s. Echelon creates LonWorks and designs the Neuron Chip with Motorola, then Toshiba. The protocol is standardised as ANSI/EIA-709.1 in 1999, then ISO/IEC 14908 in 2008 (source: lonmark.org). Installation becomes widespread: thousands of commercial buildings in France and around the world adopt the Local Operating Network. BMS integrators standardise their projects around LON. The installed base peaks in the mid-2000s.
Acquisition of Echelon by Adesto, then Dialog Semiconductor and Renesas
Adesto Technologies acquires Echelon in 2018 for $45m[2]. Dialog Semiconductor absorbs Adesto in 2020[3], then Renesas acquires Dialog in 2021 for $5.9bn[4], i.e. EUR 4.8bn. The LonWorks intellectual property - protocol, chips, development tools - ends up concentrated at a semiconductor manufacturer. Building automation is not the core business of Renesas. The life of the product now depends on a player for whom LonWorks is a marginal revenue base. The life cycle enters its decline phase. EOL (end of life) becomes a matter of timing.
Renesas 2025 announcement: official end of life for LON components
2025. Renesas confirms the end of production of LON components: the FT 5000 and FT 6050 chips will no longer be manufactured, with last orders by 15 September 2025[5] and last shipments by 15 March 2026, with no replacement product (the LonMark FAQ of July 2025[1] sets out the consequences). This is the official end of life - EOL (end of life) in the industrial sense. The term “end of life” is no longer a projection. It denotes an official status: the end of life familiar from IT, applied to physical components. The manufacturer stops producing. Once stocks run out, no new chip will be available. EOL, or the end of the LonWorks supply chain, now comes with definitive vocabulary.
Expert tip Before signing a quotation for the complete replacement of your LON network, have someone check which controllers are genuinely at end of life and which still have spare parts available. An independent audit avoids the premature replacement of working components.
Where LonWorks stands in October 2026
LonWorks is a protocol, not a manufacturer range. Here is the status of the chips, the tools and the LON ranges mentioned above, as of the date of this article:
- Renesas chips: notice PCN 075 set last orders at 15 September 2025 and last shipments at 15 March 2026[5], with no replacement part number. Both deadlines have passed: Renesas no longer ships new Neuron chips.
- Protocol: LonMark states that installed networks and devices continue to work[1] and that the protocol is still supported. The constraint is the availability of the Neuron chip.
- Alternatives without a Neuron chip: LonMark lists Babi-LON, FetLON and open-source LON stacks[6], which run the protocol on off-the-shelf microcontrollers. These solutions are aimed at manufacturers, and LonMark warns of a likely gap between the discontinuation of current LON products and the arrival of redesigned ones.
- Commissioning tools: according to the LonMark status update of February 2026[7], the current versions of IzoT Net Server and IzoT CT have been discontinued and EnOcean is developing new ones, compatible with the legacy versions. Tools and licence keys shipped before 1 February 2026 are not affected.
- Distech ECL: the line (controllers, routers, network cards) is phased out. Orders had to be placed by 15 August 2025, with final shipments planned by 30 April 2026[8], then a safety stock while supplies last. The manufacturer points to its Eclypse (ECY) controllers.
- Schneider TAC Xenta: the TAC Vista range, which covers Xenta, is listed as “Discontinued” in the Schneider Electric catalogue[9], with no date given.
On your estate, record the part number of every LON controller and ask your maintenance contractor in writing what spare stock they hold. In a quotation, require every new LON device to state its hardware base: a Neuron chip from stock, or a LON stack on a standard microcontroller.
Self-assessment sheet
Where does your LonWorks estate really stand?
A sheet to place your installation before discussing a quotation: generations in place, end-of-support dates, points to check. Enter your work email and we will send it to you.
BACnet, Modbus or multi-protocol gateway: which scenario for replacing LonWorks?
BACnet: the dominant replacement protocol in BMS
BACnet (Building Automation and Control Network) is the ASHRAE 135 / ISO 16484-5 standard. This open protocol covers HVAC, lighting and fire safety natively. Its client/server architecture guarantees interoperability between manufacturers with no proprietary chip. Almost all BMS manufacturers now support it. For a LON estate, BACnet is the natural successor: open, documented and widely supported by active integrators. Implementing it remains the reference scenario.
Modbus: a limited alternative for some equipment
Modbus (serial or TCP-IP) excels at reading registers: energy meters, temperature sensors, sub-metering. The protocol remains simple and robust. Its limits confine it to a supporting role: no automatic object discovery, no native alarm management, no high-level interoperability. In a LonWorks migration project, Modbus covers the peripheral equipment. BACnet, Modbus and LonWorks (in French) often coexist as a trio during the transition, each variable being read by the appropriate protocol.
Multi-protocol LonWorks-BACnet gateways: migrating without replacing everything
A multi-protocol gateway translates LON frames into BACnet frames. The owner migrates zone by zone, without stopping operation. Manufacturers such as WAGO and Loytec (or Intesis) offer this hardware interface. Integration takes place between the existing LON network and the target BACnet supervision. Zone-by-zone migration limits the risk of HVAC interruption. One limit to be aware of: the gateway keeps a residual dependence on the LON network. Support remains conditional on the availability of the controllers upstream.
Full replacement vs phased migration: cost-risk-lead time comparison table
Alternatives to the end-of-life LonWorks protocol
Click a row to display the migration details
| Protocol | Interoperability | Native IP | Longevity | Migration cost |
|---|
Sources: ASHRAE BACnet Committee 2024, KNX Association, Navigant Research BMS report 2023-2025, BMS integrator field feedback.
The choice between full replacement, phased migration and a mixed approach depends on the real condition of your LonWorks network. A prior audit determines which controllers (TAC Xenta, Distech ECL, Sauter, Honeywell) still work and which justify replacement. Without this diagnosis, you risk replacing working hardware or underestimating the critical zones. Occupant thermal comfort also shapes the phasing: a phased migration keeps control active during the works. The end of life of a component does not mean that the whole network has to go in a single operation.
Your LON estate deserves a diagnosis before a quotation. We audit the real condition of your controllers and test the feasibility of a gateway before any replacement decision.
Request an “Obsolete” BMS audit
The checks to demand before signing a LonWorks replacement quotation
Tick each point validated for your estate
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✓
1. Exhaustive inventory of LON controllers
List every controller by zone and by function (HVAC, lighting, metering).
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✓
2. Real condition of each controller
A working controller is not obsolete on age alone. Test before replacing.
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✓
3. Communication test on the LON bus
Identify silent nodes, frame losses and abnormal response times.
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4. Volume of controlled points per zone
Quantify the inputs/outputs to size the gateway or the replacement correctly.
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✓
5. Real availability of spare parts
Check the remaining manufacturer stock and the secondary market. Put figures on lead times and extra costs.
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✓
6. Multi-protocol gateway compatibility
Not all LON modules are compatible. Test the firmware generation and the node type.
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7. EOL clause in the maintenance contract
What does the contract provide for if parts become unobtainable? Does the warranty cover this risk?
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8. French BACS decree compliance maintained
The decree covers functions, not the protocol. Check that the functional capabilities are still delivered.
One unticked point = one grey area in the quotation
Controller inventory and real condition of the network
First check: draw up an exhaustive inventory of the LON controllers by zone and by function (HVAC, lighting, metering). Each controller is identified, located and attached to its control scope. Second check: assess the real condition of each controller. A working controller is not obsolete on age alone. Software at end of support on operational hardware does not justify immediate replacement if the networks remain stable and the functions are delivered.
Communication test and analysis of the volume of controlled points
Third check: the communication test on the LON bus. Nodes that no longer respond, frame losses or abnormal response times signal a degradation of the communication protocol. This diagnosis reveals the zones at risk before the failure. Fourth check: quantify the controlled points (inputs/outputs) per zone. This sizing drives the choice between gateway and replacement. Every unmapped variable becomes a blind spot in the quotation.
How does Foobot support the transition of your LonWorks estate?
“Obsolete” BMS audit: the second opinion on real obsolescence
The “Obsolete” BMS audit assesses the real condition of the LON network. This diagnostic tool reviews every controller, every zone and every bus to determine what still works and what justifies replacement. A building management system cannot be reduced to the end of life of its protocol. A LON network made reliable can run for several more years. The audit provides an independent second opinion: it establishes the replacement tests needed before approving a quotation.
Replacing LonWorks: the 3 phases of a successful BMS migration
Click each phase to discover the key steps, the pitfalls to avoid and the expected results.
With Renesas discontinuing the Neuron components, migrating to BACnet/IP becomes unavoidable to maintain the energy performance of your commercial buildings. Here is the path in 3 phases.
Map all the LonWorks controllers, regulators and gateways installed: models, firmware, year of installation, working condition.
- List every LonTalk node on the network
- Check the compatibility of the controllers with a LON/BACnet gateway
- Identify obsolete equipment with no spare parts
- Document the control sequences in place
- Estimate the remaining service life per technical package
Assess the impact of a LonWorks failure on comfort, regulatory compliance (Décret tertiaire) and operating costs.
- Rank the buildings by criticality level
- Identify the sites where integrator support has already stopped
- Establish an urgency / feasibility / budget score
- Define the migration batches in order of priority
- Plan fallback scenarios in case of failure during the transition
Write the functional specification for the target BMS, including the requirements for BMS class (NF EN ISO 52120-1, formerly EN 15232), BACnet interoperability and energy control.
- Specify the target BMS class (class A or B depending on use)
- Define the BACnet points to be reported per HVAC package
- Plan for the integration of energy control on top of the supervision
- Build the Décret tertiaire milestones into the schedule
- Set the handover criteria: response time, rate of points in fault
Install protocol gateways so that the LonWorks equipment still working can communicate with the new BACnet/IP bus, without stopping operation.
- Select BTL-certified gateways (BACnet Testing Labs)
- Configure the mapping of LonWorks objects to BACnet objects
- Test every point in read and write before going live
- Keep the LonWorks network running in parallel during the transition
- Document the LON/BACnet mapping table for maintenance
LonWorks controllers whose firmware is no longer maintained or which cannot support a gateway must be replaced by native BACnet controllers.
- Favour multi-vendor BACnet/IP controllers
- Take over the existing control sequences and optimise them
- Plan the shutdowns package by package to limit the impact on occupancy
- Check the complete chain: sensor → controller → supervision
- Issue a handover certificate for each migrated zone
Connect the new BACnet points to the existing supervision or set up a new compatible BMS supervisor.
- Configure automatic discovery of BACnet objects
- Create the graphics and dashboards per building
- Configure the alarms, thresholds and data logs
- Train the operations teams on the new interface
- Validate secure remote access for remote control
Once the BACnet BMS is operational, deploy an energy control layer to optimise consumption continuously.
- Connect the control layer to the reported BACnet points
- Adjust the control laws to real occupancy
- Program the optimal starts (heating, cooling)
- Define the IPMVP energy baseline to measure the gains
- Configure the consumption drift alerts
Track the actual results against the baseline and produce the compliance reports for the Décret tertiaire.
- Compare monthly consumption with the IPMVP baseline
- Generate the certificates for the OPERAT platform
- Identify the remaining sources of overconsumption
- Adjust the control parameters continuously
- Document the gains in kWh/m² and in tCO2e avoided
Extend the approach to the other buildings in the portfolio and refine the control strategies based on field experience.
- Deploy on the next sites in order of priority
- Integrate new HVAC packages (ventilation, lighting, blinds)
- Use the historical data to refine the control algorithms
- Benchmark the sites against each other to identify best practice
- Aim for the next Décret tertiaire milestones (2030, 2040)
LonWorks migration does not require replacing all the hardware. A gateway + control approach makes the most of what exists while modernising the BMS, without stopping operation.
Sources: ASHRAE, NF EN ISO 52120-1 standard (formerly EN 15232), IPMVP protocol, feedback from commercial BMS migration projects 2024-2026
FAQ - LonWorks end of life
Where can you find the end-of-life (EOL) date of a LonWorks device?
Check the website of the controller manufacturer (Schneider, Honeywell, Sauter) for the official EOL date. The end-of-production date for LON chips at Renesas has been confirmed since 2025[1]. Manufacturer support varies by range.
Has your equipment passed its EOL date?
Equipment that has reached end of production can no longer be supplied with new parts. Check whether your LON controller has reached the end of manufacturer support. If so, hardware end of life is under way.
What is end of life (EOL) in IT and how do you identify it?
End of life (EOL) is the point at which a manufacturer stops producing and maintaining a product. In IT, the life cycle comprises production, extended support, then complete shutdown. Check the manufacturer bulletins.
What are the risks of obsolete IT hardware?
Three major risks: security vulnerabilities left unfixed after the end of support, loss of specialist technical support and unavailability of parts. Every unanticipated problem turns into an interruption of HVAC control.
How can I extend the life of my servers and IT equipment?
Keep the firmware up to date for as long as the software at end of support receives patches. Explore support through multi-protocol gateways. Some components have community open source firmware. Adapting or modifying the code remains an option on programmable controllers.
Can end-of-life (EOL) equipment remain covered by a maintenance contract?
After the end of manufacturer support, standard support disappears. A third-party contract remains possible as long as parts exist. Cover for the remaining life cycle is negotiated case by case. When the manufacturer stops production, the maintenance contractor carries the risk alone.
What is LON / LonWorks?
LonWorks technology (Local Operating Network) relies on the LonTalk protocol, a fieldbus standardised as ISO/IEC 14908. LON enabled decentralised communication between HVAC controllers in commercial buildings. Its components are now at end of life.
Sources and references
- [1]LonMark International, "LonWorks Technology Transition – Frequently Asked Questions", July 2025 (PDF) ↑↑↑↑↑
- [2]Renesas (newsroom), "Adesto Completes Acquisition of Echelon", 2018 ↑
- [3]Design & Reuse, "Dialog Semiconductor Announces Completion of its Acquisition of Adesto Technologies", 2020 ↑
- [4]Renesas, "Renesas Completes Acquisition of Dialog Semiconductor", 2021 ↑
- [5]Renesas, "End Of Life Notice – PCN 075", 28 March 2025 (PDF) ↑↑
- [6]LonMark International, "Development Resources" ↑
- [7]LonMark International, "LonWorks Migration Playbook & Next-Gen Options", AHR Expo, February 2026 (PDF) ↑
- [8]Distech Controls, "End of Life (EOL) notice for Distech Controls LON products", 18 June 2025, Internet Archive copy (PDF) ↑
- [9]Schneider Electric, TAC Vista range page (status "Discontinued") ↑