Hey! I'm working at my first software internship and I will very soon be doing some PLC programming on moderately important chemical equipment. Do you have any tips on how to not spectacularly fuck everything up?
In general, make the code easy to interpret, especially when debugging - which means organizing your code and using simple abstractions. State machines can be useful because they're easy to interpret if you comment your states, leading to high-level understandings like "the machine is waiting for an item" rather than "it will do something when I0.5 goes high".