Key points
- A working station depends as much on lighting, mounting, PLC signals and the reject as on the camera.
- Three kinds of supplier offer vision: camera distributors, general automation integrators and vision-specialist integrators.
- Ask every supplier to prove the defect on your own samples before you buy hardware.
- Write the false reject rate, the missed defect rate and how both are measured into the contract.
- Agree who changes the PLC, who supports the station, and how fast, before you sign.
What a machine vision integrator does
A machine vision integrator turns an inspection requirement into a station that works on your line, every shift. The camera is one part. Whether the station works depends just as much on the lighting that makes the defect visible, the mounting and presentation of the product, the trigger, the PLC signals, the tracking to the reject, the reject itself and the tests that prove all of it. An integrator is the party accountable for that whole chain.
Three kinds of supplier
Buyers in South Africa usually meet three kinds of supplier. Each can be the right choice; the table shows when.
| Supplier type | What they do | Good fit when | Check |
|---|---|---|---|
| Camera or component distributor | Sells cameras, code readers, lenses and lights; often helps configure them. | You have your own engineers who will build and integrate the station. | Integration, reject and acceptance usually stay with you. |
| General automation integrator | Builds PLC, motion and machine automation; vision is one of many services. | Vision is a small part of a larger automation project they are already doing. | Check their depth in lighting, optics and inspection acceptance. |
| Vision-specialist integrator | Designs and delivers inspection stations: optics, lighting, software, PLC link, reject, FAT and SAT. | The inspection itself is the project, and you want one party accountable for the result. | Check that PLC and mechanical scope are covered, not only the camera. |
Ten questions to ask
Ask every supplier the same questions and compare the answers side by side. Vague answers to the first three are the strongest warning.
- Samples: Will you test our own good and defective products before proposing hardware, and show us the images?
- Limits: What can the station not detect on our product, and why?
- Metrics: How will the false reject rate and the missed defect rate be defined, measured and accepted?
- Tests: What exactly is tested at FAT and at SAT, with which samples and at what speed?
- Integration: Who designs the trigger, the PLC signals, the tracking to the reject and the reject confirmation?
- PLC changes: Who changes our PLC program, and who is responsible if the line stops because of it?
- Faults: What does the line do if the camera stops, the air drops, a reject is not confirmed or power fails?
- Changeovers: How are new products and recipes added, and can our team do it after training?
- Handover: What documentation, backups, licences and spares list do we receive?
- Support: Who supports the station after handover, from where, how fast, and on what terms?
What to write into the contract
- The defect list, with reference samples of each defect and of normal good variation.
- Acceptance criteria: how the false reject rate and the missed defect rate are measured, on which samples, at what speed, and the levels agreed for FAT and SAT.
- Scope boundaries: PLC changes, electrical work, mechanical changes to the line, the reject mechanism and who does each.
- Fault behaviour: what the line does when the station stops, the reject fails or power is lost.
- Handover set: documentation, recipe backups, licences, training and a recommended spares list.
- Support terms: response times, remote and on-site support, and what counts as a change rather than a fault.
How addaScan runs these steps is described in how we deliver a machine vision integration project.
Warning signs
- A quotation for hardware before anyone has looked at your defective samples.
- A promise of 100 % detection with no false rejects.
- No mention of the reject, its confirmation, or how the failed product is tracked to it.
- Acceptance described as “it works” instead of measured rates on agreed samples.
- No plan for adding products, backing up recipes or supporting the station after handover.
Local support in South Africa
A station that stops the line needs someone who can respond. Ask where the engineers are based, what can be done remotely, how quickly someone can be on site in your province, and which spare parts are held locally or must be imported. addaScan works from Johannesburg for plants across South Africa; projects elsewhere are confirmed case by case. See about addaScan and support after handover.