What I'd say for a start is this:
PLCs, VSDs, hydraulics, pneumatics, etc.
How good is your knowledge of these sorts of equipment?.
PLC's in themselves take a bit of work to learn.
Before I went back to Line-Work I worked as an Industrial Electrician and I was only just getting used to Pneumatics.
It's totally different to any Electrical Theory, as is Hydraulics.
Mind you, a VSD (Variable Speed Drive) is reasonably easy to set up and program, provided you know the parameters in the first place.
Having spoken to a lot of Pneumatics Technicians here, it's a very involved Trade within itself.
Same with Hydraulics, we had a Hydraulics guy here the other day looking at our "Jaws of Life" cutting/spreading gear, he was saying that the oil inside of the supply line runs at 350 MPascals, probably more under load.
I'm not trying to scare you away from a job, but you have to know what you are getting into.