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One of our customers had installed the TLACS lighting control and supervision solution in their tunnel in 2013 for the first tube and in 2014 for the second. The latter took advantage of a major maintenance to have its lighting system inspected in April 2022.

So Nyx Hemera Technologies offered him TLACS-PMP, the TLACS Operator Preventive Maintenance Service that provides:

  • Remote support
  • A pre-analysis of the data in the TLACS database
  • An inspection on the site
  • Software updates (if necessary)
  • An annual performance report
  • Recommendations to improve the system and facilitate its operation

The technical support team therefore first downloaded data on the status of the various elements covering a period of 4 months in order to establish a diagnosis and make recommendations.

After doing the analysis, it turned out that :

  • The software versions were up to date
  • The history of the NWC (which is the core of the control firm) did not report any anomalies
  • The history of the LCAMs (photometers installed at each tunnel entrance) was functioning normally
  • Less than a dozen of the 800 LPCs initially installed in the luminaires needed to be replaced for various reasons


Nine years after the installation of local controllers (LPCs) in the tunnel fixtures and multiple upgraded versions of the LPC, the challenge was to replace the failed first-generation LPCs with new generation LPC 480s.

With the former discontinued due to lack of spare parts and production availability, Nyx Hemera Technologies’ engineers came up with an ingenious solution. They have been able to provide interoperability in a fast and cost effective manner without compromising the speed, addressability and robustness of communications between the main controller and individual nodes.


In order to support customers towards a smooth migration from a tunnel with first generation controllers (LPC1) and gradually migrate to the latest generation controllers (LPC 480), a hybrid NWC software solution, with the NWC being the core of the main controller (LCC). This solution makes it possible to meet this need, without logistical and technical constraints, while carrying out a very short migration. By supporting both types of technologies, the solution offers a migration by project phase over a medium to long term period.

Indeed, as units are replaced, it is easy to change the system configuration at the software and database level without touching the TLACS hardware installed in the tunnels.

Updating a client’s system:

  • An existing NWC system with an internal modem is connected to the three-phase electrical network controlling an existing LPC1 group.
  • An update of the NWC software was necessary to support the new functionality.
  • A gateway (GTW) has been added to the three-phase network, and connected via Ethernet to the NWC.
  • LPC1s on the power system are gradually replaced with LPC 480s according to a replacement plan established by the customer.
  • A configuration change to the NWC was required to control the LPC 480s installed on the power grid via the GTW.
  • As soon as all LPC1s are removed from the power grid, it would then optionally be possible to remove the coupling of the NWC (internal modem) to the power grid.

Therefore, the NWC software was modified to include a routing feature that ensures that when the NWC needs to communicate with an LPC 480 node, it is automatically routed to the Ethernet.


This modification to the NWC’s on-board software and the addition of a GTW quickly met the customer’s need and allowed for an easy, seamless and progressive upgrade. In addition, this solution allowed the operator to consolidate its initial investment by keeping the equipment in good condition 9 years after installation.

Unlike some technologies where the entire system has to be replaced within a decade of installation due to new releases, with TLACS the operator can gradually reinvest in new equipment as needed and as it becomes inoperable.

This is further proof of the flexibility of TLACS and the expertise of the Nyx Hemera Technologies engineering team that powerline is a perfect solution for tunnel lighting control systems.