UK dairy vending operator
Vending Machine Software Changeover
Locked touchscreen and controller software, recovered and rebuilt, and tested in simulation before any of it goes near a machine that sells food.
18
Machines in the fleet
687
PLC tags mapped
0
Compile errors
0
Site visits to read a machine
The problem
The operator runs 18 milk and milkshake vending machines across four counties. Each one is built on a Weintek cMT touchscreen and a Siemens S7-1200 controller with a contactless card terminal. The software came as a sealed unit: no source files, a know-how-protected controller program, and no way to change a screen, a price or a cleaning cycle without going back to the original supplier. Every fault meant a drive to the machine.
What we did
- Recovered the touchscreen project from a panel on site and opened it in EasyBuilder Pro.
- Recovered the full address map, 687 tags, each tied to its data block, byte and bit, and documented it so the touchscreen, the controller and any cloud system agree on every address.
- Rebuilt the touchscreen software, compiling with zero errors and walked through end to end in the simulator.
- Re-implemented the controller logic in TIA Portal and began testing it against a simulator of the original machine.
- Read each machine's temperature and sales logs remotely through the panels' own secure remote-access service, so nobody has to drive out to see how a machine is behaving.
How the changeover is run
Nothing goes onto a live machine that sells food until it has been proven offline. Before any changeover we keep a written register of every risk that could stop the line, from wash cycles to payment timeouts, and each item has to be closed, or signed off by the operator, before work starts on site.
The changeover procedure backs up each panel's original project before anything new is loaded, and changes only what has been tested. The address map and the documentation stay with the operator, so the next change does not depend on one supplier.
Where it stands
The address map is complete and the rebuilt touchscreen software compiles cleanly. The new controller logic is running in simulation, where testing is still turning up issues to fix before any release is frozen, and the build still has to be adapted for both panel sizes in the fleet. On-site commissioning follows once the changeover register is clear and the operator signs off. The same remote access already feeds the operator's new operations dashboard.
Technology
- Weintek EasyBuilder Pro
- Siemens TIA Portal
- S7-1200
- Structured text
- Python
- Secure remote access