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.
- The 7 Essential Parts of a PLC System
- Here’s a Quick Way to Understand PLC Inputs and Outputs
- How PLC Inputs Work
- How PLC Outputs Work
- Understanding the PLC Program Scan
- Who Else Wants To Know How A PLC Scans?
- Here’s a Quick Way to Wire NPN and PNP Devices
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 Editor – Video
– 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.
- Learn PLC Programming – Free – Video Series
1 – Installing the software
2 – Your first PLC program
3 – Program Documentation
4 – Start / Stop / Jog Circuit
5 – Jog Circuit memory retentive
6 – Understanding decimal and binary numbering
7 – Binary Interpretation
8 – The Secret of Timers
9 – The Secret of Counters
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.
- Five Steps to PLC Program Development
- PLC Programming Example – Process Mixer
- PLC Programming Example – Shift Register (Conveyor Reject)
- PLC Programming Example – Paint Spraying
- PLC Programming Example – Delay Starting of 7 Motors
- PLC Programming Example – Pick and Place
- PLC Programming Example – Sorting Station (Shift Register)
- PLC Programming Example – Palletizer
The next step is to further develop your PLC environment by using an HMI. (Human Machine Interface)
- Create a PLC with HMI Training and Learning Environment Free
- Deploying an AdvancedHMI Project
- What Everybody Ought to Know About IP Addressing
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
I hope this is helpful to you.