i'm taking a plc position upgrade test at 7:00 a.m. tuesday at my company where i work and need to learn everything i can in less than 24 hours,,, don't tell me why didn't i wait to the last minute,,it's a union shop and you know how that can be...i work with relay controlled machines but everything being brought in and built here is going direct logic controlers,,,should i call in sick or what can i read now... thanks