Ladder Logic 208: System Routine 2
Today’s post is a continuation of the series on PLC Ladder Logic I started several years ago; for more of these post click on the PLC tab at the top of the site. In particular this continues my discussion of …
Tag: PLCs
Unitronics
Today’s post, as promised last week, is written by Ryan McCarthy, a reader of this blog. While I always offer to place a reciprocal link to the website of whoever contributes guest posts to this site, amazingly Ryan is neither …
Birth of the Programmable Controller
Today’s post is extracted from my new “generic” PLC course manual, PLC Hardware and Programming – Multi-Platform. In the manual, I also cover the origins of the computer, beginning with the Babbage Analytical Engine, all the way back in 1823! …
Ladder Logic 305: ASCII and Strings
Today’s post covers ASCII, string manipulation and how to deal with readable text in a PLC. The picture above is from a ControlLogix program (Allen-Bradley, RSLogix5000 v.16) I wrote back in 2006. The program communicated with a PC-based Cognex machine …
The Difference Between PLCs and Computers
What makes a PLC different from a typical computer? After all, computers are used to control things, they can even run a software PLC. This short video is part of the introduction to a new training course I am producing …
I Need PLC Pictures!
For the last few months I have been working (slowly) on my new PLC course. Before getting too far into the videos on the Thinkific site, it made sense to me to complete a training manual. Well, I completed the …
PLCopen
Industrial automation has changed drastically over the past century. From the Charlie Chaplin style factories, where companies were reliant on people to manage the factory floor, to today, where factories are highly automated with only a few people present on …
PLC Memory
As I have mentioned previously, I have been working on a generic PLC course that I hope to release in some kind of online software format soon. I was able to test a prototype a few weeks ago with a …
Update on Projects – “Why haven’t you written more posts?”
I have been asked by a lot of readers, friends and associates lately about where I’m at on the various projects I’m involved in. There has also been an undercurrent of “why haven’t you posted lately?”, so I figured I’d …
Update on Projects – “Why haven’t you written more posts?” Read more »
Ladder Logic 106: One Shots
A one shot, or “differential”, is used to develop a signal that is exactly one scan in duration. As shown in the diagram above, when a signal is applied to a contact (a Pushbutton in the diagram above), no matter …