The Challenge
A major UK automotive manufacturer was running production-critical machinery on Modicon control systems that had been in continuous operation since the 1990s. Across more than 200 metres of conveyor and associated production equipment, the hardware was decades beyond its original design life.
Spare parts had become increasingly difficult to source. Vendor support had long since ceased. The knowledge base for maintaining the original systems was shrinking, and the risk of an unplanned failure on a critical production line was becoming very difficult to justify. A single significant fault on the wrong piece of equipment had the potential to cause extended unplanned downtime with serious operational and commercial consequences.
Beyond availability and supportability, the ageing architecture carried a growing safety concern. Control and power panels built to the standards of a previous era no longer reflected the functional safety expectations placed on a modern automotive production environment. The client needed more than a repair. A properly engineered modernisation programme was required.
The brief: Replace all legacy Modicon control and power panels across the facility with a current Rockwell Automation platform. Deliver the full scope in-house, from electrical design through to live commissioning, with no unplanned disruption to production.
What Duke Did
Duke Control Systems was appointed to deliver the full programme. The scope covered multiple control and power panels across the facility, with all new hardware specified around the Rockwell Automation ControlLogix 1756-L83E platform. This brought the site onto a well-supported, current architecture with a long service life ahead of it and a standardised platform that the client's own engineering team could support going forward.
Electrical Design
The programme began with a full electrical design package covering the replacement panel layouts, schematics and cable schedules. All design work was completed in-house by Duke's electrical design engineers, with drawings produced to a standard that will serve the facility for the life of the equipment.
Panel Manufacture
New control and power panels were manufactured by Duke's team before being delivered to site. Each panel was built, tested and subject to factory acceptance testing before leaving the workshop. Getting that verification done off-site, before any panel went near the production line, was central to the programme's approach to managing risk.
PLC Programming
The migration from legacy Modicon logic to the Rockwell platform was handled entirely by Duke's software engineers. The original systems carried no usable documentation. Code had to be understood, interpreted and rewritten from scratch on the new platform, with all the functional requirements of the original system preserved and a number of improvements incorporated alongside.
Site Installation and Commissioning
With panels manufactured and software tested, Duke's engineers moved to site for installation and phased commissioning. The work was planned in stages around live production, with each phase carefully coordinated with the client's operations and engineering teams. At peak, 12 people were working on the programme across electrical design, panel build, software and onsite disciplines.
Every intervention on a live production site carries risk. The way you manage that risk is through preparation. By the time our engineers went live on each phase, the panel had been factory tested, the code had been bench tested, and the cutover sequence had been rehearsed. That preparation is what keeps the line running.
Safety Improvements
The move to a current Rockwell platform brought meaningful improvements to the functional safety architecture of the facility. The new panels and control systems were designed and built to current standards, replacing legacy hardware that had been operating well beyond the safety expectations now applied to automotive production environments. This was not a secondary benefit but a core part of the case for investment.
Electrical Design and Specification
Full panel schematics, cable schedules and hardware specification completed in-house. Rockwell 1756-L83E platform selected and configured for the application.
Panel Manufacture and FAT
Multiple control and power panels manufactured and factory acceptance tested before delivery to site. All wiring, termination and functional checks completed off-site.
PLC Programming and Bench Testing
Legacy Modicon logic interpreted and rewritten on the Rockwell platform. Full bench test of each software module prior to site deployment.
Staged Site Installation and Commissioning
Phased delivery across the live production facility, coordinated around production schedules. Each phase handed over with the line running.
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The programme is currently underway and progressing well. No unplanned production downtime has occurred at any point during the implementation, which on a live automotive facility of this scale is a meaningful result. The staged approach, combined with rigorous preparation at each phase, has kept the line running throughout.
The client's engineering and production teams have remained closely engaged throughout the programme, and the feedback has been consistently positive. The project is on track to complete in December 2026.
When complete, the facility will have a fully modernised control estate across more than 200 metres of production conveyor, built on a supported and maintainable Rockwell platform, with improved functional safety, better diagnostic capability, and control architecture that reflects the demands of a modern automotive production environment.