to Ianingram, thank you for your help. I would agree with you that the internet is not the ideal place to learn plc's. It is my fascination with hardwired motor control and relay based automation (if there is such a thing) that has led me to this point in the first place. I also understand the rare atmosphere that surrounds the people working in this industry. I appreciate anyone who cares enough to help, or loves their trade so much that they cannot resist giving constructive criticism and advice. I am making $15 an hour hammering boxes on studs and jerking romex. It's mind-numbing. A plc software programmer that was being paid $50 an hour told me, "If I want to know something, there's a book written about it, and if I don't understand the book, ask someone who knows". I'm not the brightest one in the bunch, but an accomplished artist once told me that it's 5% talent and 95% perseverance. Whether that's true or not, I decided last week to do this, and this forum was my first stop after reading a book on plc's that I bought at Barnes and Noble. I promise not to waste your time.
To Frelecing: yes sir, I did load the program onto a brand new twido, and it worked fine. As I mentioned before, I have no clue why the inputs quit working. Inputs 0 and 1 were attached to a hand-off-automatic switch on the front of the cabinet. Thanks for the advice........"So what I would do is to open the program, (save it with another name, before applying any changes) and with the search/replace option (I believe it's Ctrl+f) find every reference to inputs %IO.0 and %IO.1 and replace them with the ones you'll be using instead." There's a test cabinet with a place for my Twido and an Altivar 31. I'll post within a few days, letting you know if it works! Also, how do I post the program online?