Practical Tips and Techniques
Automation Direct programming software Do-More Designer with and integrated simulator. This is offered free of charge.
I have been writing PLC programs for over 20 years. I often get asked what the best way to learn PLC programming is. Programming in the way I was taught in college was with the Motorola 6809. (Yes, I know that I am dating myself) This was microprocessor programming, but it was the best way … Read more
We will look at how to troubleshoot a plc racing condition. Two examples are explained in racing conditions in the PLC. The PLC will update only at the end of the program logic. Items set will not happen until the I/O is refreshed. How to trigger events when you want them is discussed. Your control … Read more
PLC programming involves both direct and indirect addressing. Direct address programming involves writing each ladder logic rung to do the operation required. We often forget about using powerful indirect addressing to solve our logic. Indirect Addressing – Faster PLC Program The below-animated picture will show a simple example of using indirect addressing. This will use … Read more
Looking at a stop-start jog circuit in the PLC will help us understand the differences in hard-wiring the circuit and programming. Basic Start Stop Circuit Let’s start with the primary start-stop circuit. Here is what it looks like hard-wired. (Physical switches wired to outputs devices, such as motor contactors and relays.) When the start pushbutton … Read more
I am adjusting for daylight saving time (DST) in Do-More PLC. When does daylight savings time (DST) start and end? On the first Sunday in November, areas on Daylight Saving Time return to Standard Time at 2:00 am local time. Canada Daylight Saving Time begins at 2:00 am local time on the second Sunday in … Read more
Now You Can Have Robust Data Logging for Free – Part 12 HTML and Scripting Languages We have the following accomplished: PLC program Visual Basic Program Data collected in a Database IIS web service established ASP Script Written Let’s take a closer look at the ASP Script ( AccRL.asp) that was written in part 11: … Read more
