Called for a press not being able to unload - so it had to a PLC problem. Traced it to a bad cable going to a photoeye that terminates in a junction box on the side of the press.
Just look at the photo..............................
It's obviously a safety feature. There is some very dangerous 'lectricity in that there box! I mean, just look at the sticker! We have to protect people from all the volts!
Excellent! So they're all very safe then! Well, electrically, I mean. They could probably still take your arm off mechanically, but at least you won't be electrocuted while it's happening.