PLC manufacturers hold seminars and classes all the time. Do you work in manufacturing? Do you have any PLC's in your facility? If so, check with the vendor that provided the equipment and ask about training. Also, check different manufacturers on the web and see if they are offering something that interests you.
When I was in this business, we always had some kind of training going on for our customers.
Your question is a good one as I had trouble getting people to attend these classes even when we paid for their trip, lodging, entertainment and 3 meals a day.