PLC ain't all that bad. As someone that studied BEng Mechatronics, I can assure you that it won't make any difference having a degree or not. I do however think it comes with lots and lots of stress and the inability to escape your job: always on call, working 7 days a week is normal, no stability in your schedule etc.
However, you get to level up much quicker than in software, there is a higher demand (you can be pretty mediocre and still have a job), you'll learn a lot more varied skills that would allow you to become a project manager, or manager for any industry in general after a few years, ability to travel anywhere in the world and earn serious $$. There are even times when you need to do support and production gets cancelled after and hour or two and you still get paid for the full day.
But, its a notorious industry and you really need to be ballsy to succeed. If you don't see yourself as a hands-on person and prefer a comfortable desk job with normalish hours and not having to deal with angry people all the time, my advice is to jump ship immediately. Sure, you can go over to software after a while, but you will be miserable until then. Did I mention the part about using a factory toilet?