Service
Machine retrofit and plant upgrade
The plant already exists. It runs, it makes money, and the controller inside it went out of production nine years ago. This is the work we are built for.
A retrofit is a different discipline from a new build. On a greenfield project the risk is that you finish late. On a retrofit the risk is that the plant does not restart, and that risk is carried by production, not by the project.
So the planning is inverted. We start from the shutdown window you can actually give us and work backwards, doing as much as possible while the plant is still running: new panel built and tested off-line, new controller programmed and simulated, cabling pre-run and pre-labelled. The window itself gets used for the changeover, not for engineering.
Migration paths we run regularly
| From | To | The part people underestimate |
|---|---|---|
| Allen Bradley PLC-5 / SLC-500 | ControlLogix or CompactLogix | Instruction behaviour differs; direct conversion output needs reviewing line by line. |
| Allen Bradley | Siemens S7-1500 | A rewrite, not a conversion. The value is in restructuring the logic while it is open. |
| Siemens S7-300 / S7-400 | S7-1500 (TIA Portal) | Rack and I/O addressing changes, and old STEP 7 blocks rarely port cleanly. |
| WinCC Flexible | WinCC Unified / Advanced | Screens and scripts are rebuilt. Treat as new development. |
| Obsolete VFDs | Current SINAMICS / PowerFlex / Altivar / VLT | Mechanical fit and cable gland positions, not the drive parameters. |
| Relay logic | PLC control | Nobody has documented the actual sequence in twenty years. Recovering it is most of the job. |
How we plan a changeover
- Step 01
As-found survey
What is actually installed, not what the drawings say. Photographs, I/O count, network topology, spares held, licence position, backup state.
- Step 02
Migration path and risk register
The recommended target platform, what it costs, what it does not fix, and what could go wrong on the night with a named mitigation against each item.
- Step 03
Off-line build and proving
New panel built and FAT-tested, new program written and simulated, screens developed — all while the plant runs.
- Step 04
Rollback proved
The old system stays intact and restorable until the new one has run production. A rollback plan that has not been tested is not a rollback plan.
- Step 05
The window
Hour by hour, agreed with production, with a defined abort point past which we go back rather than push on.
- Step 06
Restart and watch
An engineer stays on site through the first production runs. Hand-back is a decision, not a date.
Why a small team wins this work
Retrofit rewards senior engineers who can make a decision at 2am on the plant floor. It punishes large project structures where the person on site has to phone somebody to approve a change. That is the whole of our advantage here, and it is why we lead with this service rather than greenfield mega-projects.
Questions we get asked
Next step
Have a machine retrofit & plant upgrade enquiry?
Send the plant detail — platform, I/O count, what has gone wrong, and the window you can give us. An engineer picks it up.
An engineer responds within as soon as possible.