Tag: programming

Ladder Logic 306: Simulation

Today’s post relates to a new method I am using to teach some of my advanced classes. In a basic PLC training class, pushbuttons and pilot lights built into a trainer are used to complete exercises, usually in order to

Share
Posted in PLCs, Software & Programming, Training Tagged with: , , , , ,

MRO – Moving HMI Designs

Today’s post is a guest post on HMI programming from MRO Electric, an automation product supplier. Designing HMIs for Mobile Devices Well-designed human-machine interfaces (HMI) reduce operator error, saving companies millions of dollars by reducing down-time and increasing worker safety.

Share
Posted in Guest Posts, HMIs, Software & Programming Tagged with: , , , ,

Ladder Logic 403: Message Scrolling and Multiple Faults

Today’s post is in answer to a question from Bruno on my last post on Faults and Messages. Bruno asks “If two faults happen at the same time, will this procedure work?” This is a more complex question than it

Share
Posted in PLCs, Software & Programming Tagged with: , , , , , ,

Ladder Logic 209: Faults and Messages

This post is another in my series on Ladder Logic. As with the other posts in this series, I am using generic logic and addressing so that it can apply to various PLCs. In previous posts in this series I

Share
Posted in HMIs, PLCs, Software & Programming Tagged with: , , , , ,

Advanced PLC Training using Industrial Equipment

I just got back from teaching a class in California using the conveyor and training demo mentioned in my previous post on Automation NTH. I have discussed training quite a bit on this blog before, but I feel like this

Share
Posted in Training Tagged with: , , , , ,

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

Share
Posted in PLCs, Software & Programming Tagged with: , , , ,

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

Share
Posted in PLCs, Software & Programming, The Book Tagged with: , , , , ,

Tag Structures and Dotfields

Today’s post is in response to an e-mail I received asking for my thoughts on Tag Structure. In part, George Steel wrote: Great site, thanks for all your efforts. I am working on positioning my org to move from RS500

Share
Posted in Controls Design, Documentation, Software & Programming Tagged with: , , , , , , ,

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

Share
Posted in PLCs, Software & Programming Tagged with: , ,

Why BCD?

Computers hate decimal. I mean, just because we have ten fingers and ten toes, we think we can dictate what base other computing entities should think in. Well, it’s really quite inefficient when you think about it, its so easy

Share
Posted in Software & Programming, Training Tagged with: , , , , , , , ,