Today's article is the first in a news series I'm writing in which I'll review books about PLCs.
To start, I'm going to review those PLC books which are free to read with a $10/mo Kindle Unlimited subscription, since I'm already a subscriber and it makes sense to start with books I already have access to.
First up is, “Introduction to Programmable Logic Controller & Ladder Logic,” by Kiran Nule and Seema Vishwakrma, with the subtitle, “Learn about Functional Operations Timers, Counter with Practical examples.”
In case you're wondering that's not a typo, but the exact text from the book's cover as can be seen in the below image (more about that later):
As one might expect, a book with the word “introduction” in the title is aimed at new users, which this book is coming in at just 99 pages and costing just $2.99 for the Kindle Edition.
A quick look at the table of contents below confirms this, and in-fact it mirrors my original PLC Basics course from 2014:
- Intro to PLCs
- PLC Scan
- PLC Advantages & Disadvantages
- Basic Ladder Logix Symbols
- And, Not, Or operations
- Timers and Counters
- Practical PLC programming examples
- Illustration of PLC Scan
- Problems to Solve on your own
The first thing I noticed as I started reading this book was that, unfortunately some of the sentences were phrased awkwardly, giving me the impression that English was not the author' first language.
While it wasn't so often or bad that I couldn't continue reading it, it's a shame that this intro to PLCs is marred by what comes down to a lack of editing to fix these issues as well as a hand full of typos.
That said, after what I would call a standard introduction to PLCs, it started to become clear the authors were not coming from an Allen-Bradley PLC point of view. In fact, if I had to guess I would say they were coming from a Siemens perspective based on some of the terminology they used.
Why is any of that important? Well, the book is being sold in English on the US version of Amazon's website, and in the United States Allen-Bradley has a lion share of the PLC market.
Even still, I have to give the authors' credit for the sections on (4) Basic Ladder Logix Symbols, (5) And, Not, Or operations, (6) Timers and Counters, (7) Practical PLC programming examples.
Chapter (4) is your standard fair of explaining the symbols and operation of Contacts and Coils.
Chapter (5) really shines in my opinion as the authors include logic symbols, truth tables, wiring diagrams, and ladder logic for each of the operations covered (AND, OR, NOT.)
Timers and Counters are also covered well in Chapter (6), although many A-B users will be left wondering why a RTO instructor is referred to as a TONR, and probably even stranger is why the universally accepted CTD instruction (ref. IEC-61131-45-2A ) is referred to as a CDU?
That, and anyone who has used PLC's other than Rockwell will know, the parameters of IEC Timers and Counters (IN, .PV) are quite different from those Rockwell uses (.EN, .PRE)
Section (7) was also well done including many examples that new users should find helpful. The only problem is none of the images of the example programs, or for that matter in the entire book, seem to support scaling on either iOS or Windows 10.
This is not a problem that I've seen before, and I've read hundreds of books using the Kindle app.
The book concludes with five programming “word problems” for the reader to solve. Based on what is covered in the previous chapters, I feel confident readers would be able to modify the previous examples to complete these challenges.
In summary, I believe with some editing and additional examples using Allen-Bradley PLCs, this could definitely be a book I could recommend. But as it stands now, I think those in the US would better served by looking elsewhere for an introduction to PLCs:
- Basic PLC Topics Covered
- Functions detailed with truth tables, wiring examples, and ladder
- Ladder examples cover many basics
- Not full of fluff or unrelated information
What's Not So Good:
- Awkward sentences, typos
- Much of the book does not apply to A-B PLCs or PACs
- Images do not support enlarging – very hard to set details
My Score: 3 out of 5 Stars
- Price: $2.99 (free with Kindle Unlimited)
- Formats: Kindle Edition
- Print Length: 99 Pages
- Publication Date: July 25, 2013
- Amazon Rating: 4.0 out of 5 stars
- Link: https://amzn.to/3fkb2hX