The second edition of this classic work adds valuable information about PROFINET’s role in process automation, supplementing the widely-used PROFIBUS protocol. With some theory and a lot of practical experience presented, this book is THE place to start learning about PROFIBUS and PROFINET for process.
…so it says on the back cover of Catching the Process Fieldbus, An Introduction to PROFIBUS and 
PROFINET 2nd edition. And I find that to be absolutely true. Confession: this blurb on the back cover is from me. I reviewed the second edition especially with respect to the additions about PROFINET.
James Powell has once again done a great job educating us about these industry-leading networks as used in the process industry.
Now the bad news and the good news. The bad news: you cannot buy this book. The good news: it’s free! Once again James has made electronic versions of the book available. He has a word of caution: “Please note that epub readers vary in their interpretation of the standard. We recommend the use of either Google Play Books, or Apple iBooks for best results. The Kindle version is a converted epub with the limitations inherent in the conversion process.”
You can find all three versions here on us.profinet.com.
–Carl Henning
BTW, there is some kind of rule that bloggers must indicate if they’ve been compensated to review anything. I have been; I got my free copy of the ebook!