Mostly on Software Engineering; very little on IEC 6113
This book is not worth the price. Half the book is on common information regarding Software Engineering e.g. Software cycle, process & quality. The other half book hardly discuss anything new regarding IEC 1131. I would consider it a summary of IEC 1131 and the book lacks substance or depth. R. W. Lewis or Karl-Heinz John & Michael Tiegelkamp are all better than this book.