We started PLC and HMI services this year. We would rather earn a reputation on real machines than talk about it in a brochure. That is the whole reason — there is no contract, no lock-in, and nothing to sign beyond a one-page scope sheet that says what we will do and what we will not touch.
If the day fixes your problem, that is the end of it and you owe us nothing. If it turns out to need a panel or new hardware, we will tell you what it costs, itemised, and you are free to take that to anyone.