PLC Beginner’s Guide

PLC Beginner’s Guide to PLC Programming

There are many different PLC manufacturers with different hardware and software. All of the programmable logic controllers have similar basic features. Here is how I would approach learning about basic PLCs.

Here is a list of the basic elements of a PLC system. This is common to all PLC models.

PLC’s can be programmed in several different languages. The most common are Ladder and STL.
Here is a simple online PLC ladder editor. It will allow you to create some simple ladder logic and test it.
PLC Fiddle – Online PLC Ladder EditorVideo
– Basic Gate Ladder Logic Challenges (Video Solutions available after the challenge) – AND, OR, NAND, NOR, EXOR, EXNOR
Timer Challenge (Video Solutions available after the challenge) – On-Delay Timer, Off Delay Timer, Pulse Output Timer
Counter Challenge (Video Solutions available after the challenge) – Motor Starter service Counter, Count Down, Hour Minute Second Counter
Math Challenge (Video Solutions available after the challenge) – Occupancy Count, Degree F and C, Determine the Scan Rate of PLC Fiddle
Compare Challenge (Video Solutions available after the challenge)- Motor Starter Service Stop, Flasher, Simple Traffic Light
Shift Register Challenge (Video Solutions available after the challenge) – Shift Register, Shift Register Output

If you have gone through the above material, you are probably looking to try some of this new knowledge. Here is a series based upon free software and PLC simulator from Automation Direct. Most of this information will apply to a majority of PLC manufacturers. It is all written in ladder logic.

Developing the PLC program is a process that can be clearly defined. Here is a series that will show you the five steps along with some practical examples.

The next step is to further develop your PLC environment by using an HMI. (Human Machine Interface)

What you want to do now is to look at the PLC’s that are being used in your area. What manufacturer is the most common? What are the models that they are using?

I would then try to get some hardware and software from the manufacturer that you will be using. Visit their website and contact their office for information.

Here are some free PLC manuals available on the web:
A Practical Guide to Programmable Logic Controllers
Engineering on a Disk
Lessons In Industrial Instrumentation
University of Toledo College of Engineering Technology
Information for courses in Electrical Engineering Technology

I hope this is helpful to you.

Practical Tips and Techniques