Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good basic text, but dated material

I've used Simpson to teach PLC basic at a community college in Vancouver, WA. It is a good solid text that covers much of the basics of PLCs and PLC applications. The book does not focus on one PLC brand, but uses programming examples from Modicon, Allen-Bradley and Texas Instruments controllers. Simpson has some good programming examples, but could use more.There are two issues I have with the text. The most important is that the information is dated. For example the Allen-Bradey information is all relevant to the PLC-2, a product that was obsoleted not long after the publication date, if not before. (Very confusing for my students who are trying to learn AB SLC-500 addressing which is completely different.) Second, there is very little about I/O types (AC, DC, triac, FET, etc.) and some of the important characteristics of each. If this book were revised with an eye to current industry practices, I would give it a much stronger recomendation.