Air Handling Unit Controller Obsolescence – PLC & HMI Software Replacement on Schneider Platform
Sector:
Aerospace & Defence
Type:
Software Only
Platform:
Schneider
Certification:
CE / UKCA
Summary
A customer operating a fleet of Air Treatment Units (ATUs) faced obsolescence of their existing York-platform controllers. DelaControl was engaged to develop replacement PLC and HMI software on a modern Schneider EcoStruxure platform, covering 19 ATU instances across multiple iterations, with on-site commissioning support included.
Challenge
The customer's existing Air Treatment Units were controlled by York Controllers that had reached end of life and become obsolete. Replacement control software was required for 19 ATU instances spanning multiple configuration iterations, to be developed on a current Schneider platform.
No formal software design specification existed to define programme structure, alarm requirements, or naming conventions, meaning the new software would need to be developed from available control philosophy documentation and I/O lists alone.
Solution
DelaControl developed PLC and HMI software using the Schneider EcoStruxure programming platform, working from the supplied control philosophy and per-unit I/O lists. Development began with the most complex ATU iteration, which was then used as donor code to be adapted for all remaining instances — an efficient approach given the number of variants involved.
Software verification was carried out by simulating using hardwired I/O test signals prior to deployment. Where no formal design specification had been provided, DelaControl applied its own standard programming practices to ensure a consistent, maintainable codebase.
On-site support visits were included within scope to assist with each ATU iteration during the deployment phase.
Key Facts
• 19 ATU instances covered across multiple configuration iterations
• Up to 17 distinct iterations when accounting for smoke damper variants
• PLC and HMI software both delivered on Schneider EcoStruxure platform
• Software verified using hardwired I/O test signals
• On-site support included: 7 half-day visits by a DelaControl engineer
• Software delivery lead time: 6–8 weeks from purchase order