PLC programming 路 Free
CODESYS and IEC 61131-3 Programming
The vendor-neutral PLC platform: ladder, function blocks, structured text, CFC and SFC, with Factory I/O projects and a visualization at the end.
Inside the course
From the lessons
CODESYS: What It Is and the First Project
RealPars
Boolean Expressions to Ladder
Instrumentation Tools
Pumps, LEDs and Multi-Output Exercises
Instrumentation Tools
Counters: CTU, CTD and CTUD
plcgoods
ST Control Flow: IF, CASE and Loops
by Tohid Alizadeh
CFC: Continuous Function Chart
plcgoods
Lesson frames belong to the creators named in the Credits below and are shown from YouTube.
What you will learn
Install CODESYS and create a project, program ladder from contacts to latching and gates, use TON, TOF, TP, CTU, CTD and CTUD, tell functions from function blocks, write structured text with IF, CASE, loops, timers, edges, structures, functions and function blocks, build CFC and SFC programs, and put a visualization on top.
- Explain why CODESYS sits inside so many PLC brands
- Build ladder from NO/NC contacts to gates, latching and exercises
- Use the IEC timers and counters and read their pins
- Tell a function from a function block and write both
- Write structured text with IF, CASE, FOR, WHILE, REPEAT, edges and structures
- Build CFC and SFC programs for a sorting station and a warehouse
- Bind a visualization to program variables
For you
Taking CODESYS and IEC 61131-3 Programming from the United States
- Free in the United States, as everywhere, and self-paced: lessons, notes and the final assessment are open at any hour, so your time zone and shift pattern do not matter.
- The optional certificate for learners in the United States is a one-off US$23.99. What you get for it
- Plants across the Americas most often run Allen-Bradley, Siemens and Inductive Automation; each has its own free course to take next.
- See automation and engineering jobs in the United States, and what the industry looks like in Houston, Detroit and Chicago.
- EDWartens also has a regional site for the United States, for classroom training and local support: edwartens.com/us.
The course project 路 about 20 hours
Polyhouse climate and fertigation control on CODESYS for Raspberry Pi: SFC, ST, FBD, Modbus TCP and WebVisu
Design, program, test and document the climate and fertigation control of a one-acre rose polyhouse in Kenya: staged fan-and-pad cooling and fogging in structured text, a three-zone fertigation cycle with EC control as a sequential function chart, wind and rain interlocks on the vents and shade screen in FBD, a Modbus TCP link to the farm weather station, and a WebVisu the owner checks from a phone, on CODESYS Control for Raspberry Pi with a PiXtend V2 -L- board. You deliver the CODESYS project, your own I/O list, interlock list and FAT record. The sample pack shows what an integrator hands a floriculture farm.
Sample document pack, 7 documents, filled in for the scenario
- FDSFunctional Design Specification: PH-3 Climate and Fertigation Control
- I/O listI/O List: Panel PH3-CP1 (PiXtend V2 -L-)
- BOMBill of Materials: Panel PH3-CP1 and Field Devices
- Interlock listInterlock and Permissive List: PH-3
- IP planIP Address Plan and Device List: PH-3 Control Network
- FATFactory Acceptance Test Record: Panel PH3-CP1
- O&M manualOperation and Maintenance Manual: PH-3 Control (Operation section)
Read inside the course and download as a workbook. The project is optional practice, marked when you submit it; the certificate needs only the modules and the final assessment.
Course content
19 modules 路 55 lessons 路 12h 17m
In order, at whatever pace suits you. Each module ends with a practice task that builds on the last.
- 01CODESYS: What It Is and the First Project4 lessons34m
- 02Contacts, Coils and NO/NC4 lessons40m
- 03Logic Gates3 lessons35m
- 04Boolean Expressions to Ladder3 lessons26m
- 05Memory Bits and Latching4 lessons36m
- 06Toggle Switches and Solenoids4 lessons35m
- 07Pumps, LEDs and Multi-Output Exercises5 lessons43m
- 08Ladder Instructions in Depth2 lessons1h 20m
Requirements
- Who it is for
- Beginner to intermediate. Ladder first, then the text and graphical languages.
- Software
- CODESYS Development System (free from the CODESYS Store) with the soft PLC What to download, and how
- Hardware
- None. The soft PLC runs every exercise.
Software you need
What to download, where from, what it costs and how to install it. Every link goes to the maker's own site, never a mirror.
Factory I/O is optional: two of the FBD and CFC videos drive its 3D scenes, and every exercise also runs in the CODESYS simulator alone.
Required
- 01Free
CODESYS Development System V3
CODESYS GmbH
- Runs on
- Windows 10 or 11, 64-bit (8 GB RAM and 12 GB free disk recommended)
- Account
- A free CODESYS Store account (one-time registration)
The Development System is free in the CODESYS Store. The setup also installs a demo of the CODESYS Control Win SL SoftPLC, which runs for two hours without a licence and then needs a manual restart.
Steps
- 1.Open the CODESYS Development System page in the CODESYS Store.
- 2.Register once for a free CODESYS Store account and sign in.
- 3.Download the 64-bit setup.
- 4.Run the installer as administrator.
- 5.Start CODESYS Control Win SL from the system tray and connect your project to it.
- When the SoftPLC stops after two hours, restart it from the system tray and log in again.
- Allow at least 12 GB of free disk space.
Official download pagestore.codesys.com
Optional
Useful, not needed to finish the course.
- 02Free trial: 30 days
Factory I/O
Real Games
- Runs on
- Windows 7 SP1 or newer, with a graphics card from 2006 (NVIDIA, AMD) or 2012 (Intel) onwards
- Account
- Your name and email on the Factory I/O trial form
The 30-day trial includes the full Ultimate Edition. After that you need a paid edition; the Siemens, Allen-Bradley, Modbus and OPC, MHJ, Automgen and Starter editions each support different PLCs.
Steps
- 1.Open the Factory I/O start trial page.
- 2.Enter your name and email and start the trial.
- 3.Download and install Factory I/O.
- 4.Open a sample scene and connect it to your PLC or PLC simulator.
- 5.Before the trial ends, choose the edition that matches your PLC.
- Choose the edition by the PLC you will use: for example the Siemens edition works with S7-PLCSIM.
- The Starter edition has its own built-in PLC simulator if you have no PLC software.
Official download pagefactoryio.com
Checked against each maker's own page on 27 September 2026. Trial lengths and editions change; the maker's page is the final word.
CODESYS and IEC 61131-3 Programming at a glance
CODESYS and IEC 61131-3 Programming is a free, self-paced online course from EDWartens for engineering students, ITI and diploma holders, and working engineers in automation, electrical and instrumentation. It has 19 modules and 12h 17m of video lessons by Instrumentation Tools, plcgoods, Tohid Alizadeh and others, with written notes and worked problems, a practical project with a document pack and a 15-question final assessment (pass mark 60%). Learning is free with an account; an optional certificate with a public verification code is issued when you pass. Last updated 27 September 2026.
All course factsHide course facts
- Price
- Free, for good. No trial, no card. The only paid item is the optional certificate, a small one-off fee.
- Who it is for
- Engineering students, ITI and diploma holders, and working engineers in automation, electrical and instrumentation
- Format
- 19 self-paced modules, 12h 17m of video, written notes, a practice task per module and one final assessment.
- Level
- Beginner. Beginner to intermediate. Ladder first, then the text and graphical languages.
- Brand
- CODESYS
- Software
- CODESYS Development System (free from the CODESYS Store) with the soft PLC
- Hardware
- None. The soft PLC runs every exercise.
- Certificate
- Optional EDWartens Certificate of Completion, verifiable by code. Not a vendor credential.
- Video lessons by
- Instrumentation Tools, plcgoods, Tohid Alizadeh, RealPars, Shane Welcher SR (independent creators, credited below)
- Language
- English
- Last updated
- 27 September 2026
A shareable EDWartens certificate
Finish every module and pass the final assessment, and the optional EDWartens certificate is yours. It carries a unique verification code on a public page anyone can check, so it stands up when a recruiter looks it up. See it below.
The course itself stays free whether or not you ever buy one.
Stuck? Ask a practising engineer
A free course usually means a comment section and hope. This one does not. Every module has an Ask-your-trainer panel that reaches the same engineers who teach our paid programme: people who commission panels for a living, not moderators.
Pairs well with
PLC programming 路 FreeSiemens TIA PortalFrom zero electrical knowledge to a working, simulated S7-1200 program, for nothing.
PLC programming 路 FreeSiemens TIA Portal in Three HoursThe first three hours of the Siemens TIA Portal course, cut to end on a win: what a PLC is, how it is wired, a project configured in TIA Portal, and your first ladder program running in simulation. Finish it in an evening or two, earn a certificate, and carry straight on into the full course.
PLC programming 路 FreeTIA Portal: Build a MachineOne machine, start to finish. Take a bottle filling line from a written specification and an I/O list to a structured S7-1200 program with a fill station, a capper, a reject sorter and an operator screen with alarms, then test it against a written record and archive it for hand-over. The lessons are the reference; the machine is yours, and it is what you submit.
PLC programming 路 FreeSiemens S7-1200 with TIA Portal: The Tutorial SeriesEvery S7-1200 instruction, one short video at a time: bits, edges, timers, counters, comparators, maths, MOVE, conversion, analog scaling, jumps and shift registers.More free courses: Free PLC programming courses
Learning paths with this course
- IEC 61131 and software PLCs 路 3 coursesCODESYS, TwinCAT and Automation Builder: structured text, PC-based control and the IEC languages behind hundreds of PLC brands.
Learner reviews
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Reviews here are written only by learners who have finished every module of CODESYS and IEC 61131-3 Programming, and they are published exactly as written. Finish the course and yours will be the first.
Common questions
Is CODESYS free?
Yes. The CODESYS Development System and its soft PLC for testing are free from the CODESYS Store. Runtime licences for real hardware are separate and not needed here.
Which PLC brands use CODESYS?
Schneider Machine Expert, ABB Automation Builder, Beckhoff TwinCAT, WAGO, Festo, Eaton and many more are CODESYS-based, so what you learn here transfers directly.
Do I need Factory I/O?
No. The projects are shown so you can follow the logic; every practice task runs on the soft PLC.
Do I need to know ladder first?
No. The first seven modules teach ladder from scratch before structured text starts.
What computer do I need for the CODESYS and IEC 61131-3 Programming course?
A 64-bit Windows 10 machine with 8 GB of RAM. CODESYS is Windows-only.
Is the CODESYS and IEC 61131-3 Programming course really free?
Yes. Every module, practice task and assessment. You create an account so your progress is saved and the assessments can be marked. The certificate is the only paid item, and only if you want it.
What certificate do I get, and is it a CODESYS GmbH qualification?
An EDWartens Certificate of Completion, issued when you pass the final assessment, with a verification code anyone can check. It is not a CODESYS GmbH credential and is never described as one.
Who made the video lessons in the CODESYS and IEC 61131-3 Programming course?
The creators named in the Credits block at the foot of this page, on their own YouTube channels. EDWartens did not make the videos and the creators are not affiliated with EDWartens. What EDWartens wrote is the study plan, the notes, the practice tasks and the assessments.
What you walk away with
Your certificate for CODESYS and IEC 61131-3 Programming
Finish the course, pass the final, and this is the document with your name on it.
Verifiable by anyone
Adds to LinkedIn in one click
QR code on the certificate
Names what you can do
A permanent link
Earned, not attended
Learning is free. The certificate is optional.
Add it now and pay only when you have finished the course, or come back for it later. One-off, US$23.99, with a receipt.
Issued by EDWartens, the training division of Wartens, as a Certificate of Completion for this self-paced course. Sold by Wartens Ltd (England and Wales). It is not a vendor certification, a university award or a CPD-accredited activity, and it does not certify competence on live equipment. Delivered electronically; see the refund policy.
Credits
Who made the video lessons
The video lessons in this course were created by the people below, not by EDWartens. Every lesson streams from its creator's own YouTube channel; EDWartens neither hosts nor sells that footage, and the creators are not affiliated with EDWartens and do not endorse this course. What EDWartens wrote is the study plan, the notes, the practice tasks and the assessments.
- Instrumentation Toolsthe CODESYS PLC training series
- plcgoodsthe CODESYS course with Factory I/O projects
- Tohid Alizadehthe Structured Text in CODESYS series
- RealParsthe CODESYS installation lesson
If you are one of these creators and would like a lesson removed or credited differently, write to info@wartens.com.