Replacing automation is not replacing the panel. The plant stays the same; the brain that runs it changes. The cost of a wrong choice is far higher than the price of the software: production stops, operators relearn, past records become inaccessible.
Below are the questions to ask when collecting quotes. If the answers are avoided, that is an answer in itself.
1. Where is the IO map kept?
This is the most critical question. If the plant’s inputs/outputs are hard-coded, you depend on the programmer every time you add a bin or change a motor.
Ask: “What do I need to do if I add a new silo?”
Good answer: it is defined in a configuration file; a line is added. Bad answer: “we’ll take care of it” — meaning an invoice with every change.
2. Where are the load cells connected?
Are the load cells connected directly to the PLC or through a weighing indicator? Both work, but with different consequences:
- Directly to the PLC: the software sees the raw value; calibration and tare are in the software
- Through an indicator: if the indicator fails, you depend on its spare parts
Whichever your current setup is, make sure the new software supports it.
3. Who owns the source code and the licence?
Are you buying the software or renting it? What happens if the company closes? Is the licence tied to the computer or to hardware? If the computer breaks, how is the licence moved?
The answers to these questions should be written in the contract. A verbal “no problem” is worth nothing three years later when that person has left.
4. Can data be exported?
In what format are production records kept? Can you get them as CSV or Excel, or can they only be viewed on the program’s own screen?
If you ever move to another system, you must be able to take your production history with you. Data kept in a closed format belongs to the programmer, not to you.
5. Is there moisture correction, and how does it work?
Recipe aggregate is dry, the silo aggregate is wet. Without moisture correction, too little aggregate and too much water go in. Ask: where is the moisture entered, can it be entered separately per fraction, can a moisture probe be connected? (details of the calculation)
6. What mechanisms are there for weighing accuracy?
At least these three should be there:
- In-flight compensation — adjustable separately for each bin (how it is measured)
- Jog feeding — the gate should pulse near the target
- Automatic tare after discharge — residue on the scale must not mix into the next batch
Without them weighing “works”, but it is not accurate. You can see how much it costs you with the waste calculator.
7. What happens when something fails?
What does the software do when a motor’s thermal protection trips? Does it only warn, or does it also stop the equipment that depends on it? Can you tell on screen which equipment failed and which stopped because it depends on it?
And the other way round: after a power cut, can production be followed from where it left off on start-up?
8. How is commissioning done?
Can settings be prepared before coming to site? If there is a simulation mode, recipes, tolerances and in-flight values can be tested beforehand and time on site gets shorter. That is direct cost.
Also: is operator training included, is a manual provided, is there remote support?
When deciding
Calculate not the price of the automation but its five-year total cost:
- Software and installation fee
- Development fees paid with every change
- Annual licence or maintenance, if any
- Cost of downtime caused by the software
A solution that looks cheap but invoices every change becomes expensive over five years. (breakdown of cost items)
Software that answers all eight questions openly: DKT CPlants · for asphalt: DKT APlants
Author: Mustafa Çelebi — 10 years of experience in software development and machine design. Founder of DKT Tasarım ve Yazılım. Develops PC-based automation software for concrete and asphalt plants (DKT CPlants, DKT APlants) and CAD-integrated job preparation tools, and commissions the systems on site.