You mean like, just hang a thumb drive on a lanyard inside of the cabinet -- with source code and such?

That will probably just disappear. Maybe with good intention or maybe with bad, but it's probably gone either way.

If it doesn't disappear, then it's hanging right there for any of the competitors to use. That's a problem for the original installer's ongoing employment.

And if it includes the programming software, then that lets Joe (from over in shipping) have a go at rejiggering the packaging machine. That's a problem for whoever has to pay someone with a clue to show up and fix it.

Even more so, if it’s just there you’re making it easy for the customer to find someone bidding less to execute new projects. Guess who they’re calling if they don’t have the plc project (or don’t understand they need it). Job security.

Plus, yea, someone could really make a mess even if they have the best intention. A guy from my company almost uploaded the wrong program to a large bioreactor. At best it would have made the bioreactor just unusable until corrected. At worst it could have broken the equipment or caused a safety issue. This guy had been around the block a few times too. Luckily someone noticed before it was too late.

> If it doesn't disappear, then it's hanging right there for any of the competitors to use. That's a problem for the original installer's ongoing employment.

Is that really an issue? Do PLC vendors have concerns about other vendors turning up and yanking USB drives out of critical infrastructure with reckless abandon? Do the facilities themselves see no issue with potential vendors yanking operational utilities out of their systems while they are running?