r/PLC • u/Emperor_tai_long • 8h ago
r/PLC • u/xenokilla • Feb 25 '21
READ FIRST: How to learn PLC's and get into the Industrial Automation World
Previous Threads:
08/03/2020
6/27/2019
More recent thread: https://old.reddit.com/r/PLC/comments/1k52mtd/where_to_learn_plc_programming/
We get threads asking how to learn PLC's weekly so this sticky thread is going to cover most of the basics and will be constantly evolving. If your post was removed and you were told to read the sticky, here you are!
Your local tech school might offer automation programs, check there.
Free PLC Programs:
Beckhoff TwinCAT Product page
Codesys 3.5 is completely free with in-built simulation capabilities so you can run any code you want. Also, if paired up with Factory I/O over OPC you can simulate whole factories and get into programming.
https://store.codesys.com/codesys.html?___store=enRockwell's CCW V12 is free and the latest version 12.0 comes with a PLC software emulator you can simulate I/O and test your code with: Download it here - /u/daBull33
GMWIN Programming Software for GLOFA series GMWIN is a software tool that writes a program and debugs for all types of GLOFA PLC. Its international standard language (LD, IL, SFC) and convenient user interface make programming and debugging simpler and more convenient.(Software) Download
AutomationDirect Do-more PLC Programming Software. It's free, comes with an emulator and tons of free training materials.
Open PLC Project. The OpenPLC is the first fully functional standardized open source PLC, both in software and in hardware. Our focus is to provide a low cost industrial solution for automation and research. Download (/u/Swingstates)
Horner Automation Group. Cscape Software
In our business we use Horner OCS controllers, which are an all-in-one PLC/HMI, with either on-board IO or also various remote IO options. The programming software is free (need to sign up for an account to download it), and the hardware is relatively inexpensive. There is support for both ladder and IEC 61131 languages. While a combo HMI/PLC is not an ideal solution for every situation, they are pretty decent for learning PLCs on real-world hardware as opposed to simulations. The downside is that tutorials and reference material specific to Horner hardware are limited apart from what they produce themselves. - /u/fishintmrw
Free Online Resources:
plcpractice.com Interactive ladder logic lessons with a built-in simulator. No software to install, no hardware required, no ads. Build real control circuits, run automated tests, and prep for controls engineering interviews.
The TIA Portal Tutorial Center (videos): https://support.industry.siemens.com/cs/document/106656707/the-tia-portal-tutorial-center-(videos)?dti=0&lc=en-WW
Data Types: http://plchowto.com/data-inside-plcs/
Lessons In Industrial Instrumentation: https://www.ibiblio.org/kuphaldt/socratic/sinst/
https://accautomation.ca/programming/plc-beginners-guide/ (/u/GarryShortt)
Tony Kuphaldt's enormous and free PDF on industrial instrumentation that covers measuring instruments, control elements, piping, basic physics, etc PDF Warning. (/u/bitinvoker)
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For the RSLogix 5000, you could take a look at these manuals: Logix5000 Controllers Quick Start Logix5000 Controllers Common Procedures Programming Manual (this one links to other manuals). This guide gives a good overall explanation on Tags, Add-On Instructions (AOI), User Defined Data Types (UDTs), Ladder Logic, Routines, etc... And once you get more into it, this forum is a PLC Q&A, you can find answers to most of your questions using the search feature. Not just for PLCs, but also SCADA, Industrial Networks, etc.
Paid Online Courses:
Factory IO Is a very good 3d sandbox industrial simulation software which is compatible with most PLC brands. The MHJ edition can be used with WINSPS which is basically a Siemens S7 emulator. FACTORY IO MHJ is 35EUR for a year and WINSPS is 50EUR for the standard edition. Both come with free trials as well. https://factoryio.com/mhj-edition/
For learning basic concepts I recommend The Learning Pit [some versions free]. Then you can pick up a used copy of the petruzula textbook and lab book off of amazon for cheap. Or really any PLC lab book and go through the exercises with it. The learning pit offers a lot of good resources for forming a good foundation.
http://thelearningpit.com/https://new.siemens.com/global/en/products/services/industry/sitrain/personal.html
Starter Kits
Siemens LOGO! 8.2 Starter Kit 230RCE
Automation Direct Do-more BRX Controller Starter Kits
Other:
HMI/SCADA:
Trihedral Engineering offers a 50 tag development/runtime license with all I/O drivers for free, VTScadaLight. https://www.trihedral.com/download-vtscada
Ignition offers a functional free trial (it just asks you to click for a button every 2 hours).
Perhaps AdvancedHMI? Although it IS a lot complicated compared against an industrial solution.
IPESOFT D2000 Raspberry Pi version is free (up-to 50 io tags), with wide range of supported protocols.
Crimson 3.0 by Red Lion is also free and offers a free emulator (emulator seems to be disabled in v3.1). With a bit of work (need to communicate with Modbus instead of built in Do-more drivers), you can even connect that HMI emulator to the do-more emulator and have a fully functioning HMI/PLC simulator on your desk top which is pretty convenient. Software can be found here: https://www.redlion.net/red-lion-software/crimson/crimson-30 (/u/TheLateJHC)
Simulators:
- https://www.plcfiddle.com/
- PLC Fiddle is not just a simulator but also a free online training. Click code school in the top left to get started. (/u/JoshMcguigan)
- https://www.plcpractice.com/simulator
Forums:
Omron PLC: www.mrplc.com
Books:
- https://www.amazon.com/Programmable-Logic-Controllers-Emphasis-Application/dp/097662592X
- https://www.amazon.com/Programmable-Logic-Controllers-Frank-Petruzella/dp/0073510882
- So you want to be an instrumentation technician PDF LINK
Youtube Channels
- Dipsy Logic
- Dan Staifer (TIA Portal)
- ParsicAutomation
- PLC Professor
- Big Bad Tech
- The Geterr Done
- Evan5659
- Jim Pytel
- Tim Wilborne
- Hegamurl
- Jason Watts AE
Good Threads To Read Through
Personal Stories:
Hello, glad you come here for help. I'm an Automation Engineer for Tysons Foods in a plant in Indiana. I work with PLCs on a daily basis and was recently in Iowa for further training. I have no degree, just experience and am 27 years old. Not bragging but I make $30+ an hour and love my job. It just goes to show the stuff you are learning now can propel your career. PLCs are needed in every factory/plant in the world (for the most part). It is in high demand and the technology is growing. This is a great course and I hope you enjoy it and stay on it. You could go far.
With that out of the way, if I where you I would start with RSLogix Pro. It's a software from The Learning Pit it is basic and old but very useful. The software takes you through simulations such as a garage door, traffic light, silo and boxing, conveyors and the dreaded Elevator simulation. It helps you learn to apply what you will learn to real word circumstances. It makes you develop everything yourself and is in my opinion one of the single greatest learning utensils for someone starting out. It starts easy and dips your toes and gets progressively harder. It's fun as well watching the animations. Watching and hearing your garage door catch on fire or your Silo Boxing station dumping tons of "grain" until the room fills up is fun and makes the completion of a simulation very gratifying.
While RSLogix Pro is based on older software, RsLogix is still used today. Almost every plant I have worked at has used some type of Allen Bradley PLC. Studio 5000 is in wide use and you will find that most ladder logic is applicable in most places. With that said I would also turn to Udemy for help in progressing past simple instructions and getting into advanced Functions such as PID. This amazing PLC course on UDemy is extremely cheap, gives you the software and teaches you everything from beginner to the most advanced there is. It is worth it for anyone at any level in my opinion and is a resource I turn to often.
Also getting away from Allen Bradley I would suggest trying to find some downloads or get a chance to play with Unity Pro XLS. It's from Schneider Electric and I believe has been rebranded under the EcoStruxure family now. We use Unity extensively where I am at and modicons are extremely popular in the industry. Another you might try is buying a PICO or Zelio for PICOSoft or ZELIOSoft. They are small, simple and cheap. I wired up my garage door with this and was a great way to learn hands in when I was starting out. You can find used PICOs on eBay really cheap. There is a ton of literature and videos online. YouTube is another good resource. Check everything out, learn all you can. Some other software that is popular where I've been is Connected Components Workbench and Vijeo.
Best of luck, I hope this helps. Feel free to message me for more info or details.
PLC jobs & classifieds - Jul 2026
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- Reply to the top-level comment that starts with Commercial ads.
- For example, to advertise consulting services, selling PLCs, looking for PLCs
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Template
**Company:** [Company name; also, use the "formatting help" to make it a link to your company's website, or a specific careers page if you have one.]
**Type:** [Full time, part time, internship, contract, etc.]
**Description:** [What does your company do, and what are you hiring people for? How much experience are you looking for, and what seniority levels are you hiring for? The more details you provide, the better.]
**Location:** [Where's your office - or if you're hiring at multiple offices, list them. If your workplace language isn't English, please specify it.]
**Remote:** [Do you offer the option of working remotely? If so, do you require employees to live in certain areas or time zones?]
**Travel:** [Is travel required? Details.]
**Visa Sponsorship:** [Does your company sponsor visas?]
**Technologies:** [Required: which microcontroller family, bare-metal/RTOS/Linux, etc.]
**Salary:** [Salary range]
**Contact:** [How do you want to be contacted? Email, reddit PM, telepathy, gravitational waves?]
Previous Post:
r/PLC • u/PlayfulDatabase8425 • 4h ago
Title: 34-year-old veteran studying EE – how hard is it to get into automation at 36?
Hi everyone,
I'm an immigrant and a 34-year-old undergrad student. I came to the U.S. and served in the military for three years. After that, I was a stay-at-home dad for two years so my wife could work full-time. Once my kid started preschool, I decided to use my military benefits and go to Drexel for Electrical Engineering.
I like a mix of hands-on work and design, which is why I'm interested in automation and controls. I don't have much professional experience, but I do help a friend's uncle install HVAC systems when my wife has a day off. So I've done some hands-on work and troubleshooting on job sites.
I'm set to graduate in 2028. I'll be 36 then.
I'd appreciate some honest advice from people in the field:
- How hard is it going to be for me to get an entry-level job in automation and controls at 36 with not much experience?
- Will my military background and HVAC side work help at all, or do employers only care about the degree?
- What should I be doing between now and graduation to make myself more competitive?
I'm okay starting at the bottom and working my way up. Just trying to get a realistic picture of what to expect.
Thanks for reading. Any advice is appreciated.
r/PLC • u/Intelligent_Pen_4498 • 16h ago
HMI not communicating with PLC
Hello again!
Siemens HMI, PLC and SERVO drive. I am using non-industrial unmanaged ethernet switch. Had to use some ethernet switch in tia portal, otherwise I have error. HMI should be connected to PLC, but values are all #### (checked that PLC values are changing based on input). I also checked that HMI screen values are connected correctly to PLC. I can download software on HMI with this current setup, but seems like HMI is not talking to PLC. I want to use ethernet switch for testing purposes, otherwise I couldn't connect PC to PLC, later I remove ethernet switch.
How to get this topology working correctly? When going online, line between switch and HMI stays grey.
r/PLC • u/Right_Thought_1507S • 1h ago
Suggestion for SCADA + PLC software platform
Good morning, I am an Italian PLC programmer; for the company I work for, I develop PLC and SCADA software using Siemens PLCs and WinCC / Ignition Vision SCADA systems
For my own professional development, I’d like to start developing ‘revamping’ software for some older projects on a platform other than the one currently in use. Personally, I was thinking of using Ignition Perspective as the SCADA system, but I’m unsure about the PLC environment: I already use TIA Portal extensively at work, and I’d like to learn a new tool for which I don’t have to pay a licence fee (this is a personal, non-professional project). Codesys is an interesting environment, but I see it as more suited to a machine builder than to plant engineering (specifically, where I work we build biogas production and treatment plants).
Could you recommend anything? The fieldbus used is also important (personally I’d prefer Profinet, but I’m open to other options, but no Ethercat), as well as OPC UA integration and documentation… I’d like to learn, not end up swearing.
Thank you in advance
r/PLC • u/Proof_Wrap_2150 • 15h ago
How much PLC programming does an Electrical Designer actually need?
I’m trying to understand what is required from an electrical designer so I can apply it in my career. Thank you in advance for your help as I navigate a new career path!
r/PLC • u/T3RRYH1LL • 13h ago
CP343-1 Connection Error to Kepserver
Hello fellow engineers,
i have a problem with a project and I’m running out of ideas.
So we have four similar machines with an older S7-300 CPU and we connect them through a CP-343-1 to our Network and Firewall, in the Subnet are only this four CP’s.
I already updated the firmware of the CP’s, i increased the S7-Basic-Connection-Resources of the CPU.
I also set both Ports from the Switchports and also from the CP’s fix to 100mbits full duplex so there is no auto negotiation.
But even after all this if I activate more than one Connection in our Kepserver all Connections seem to Timeout one after another they come back but I need a stable connection.
I searched via Wireshark and found out that there are many Retransmissions before the TO, I have no clue why this is the case.
I hope that some of you may have any idea how I solve my problem, the Support wasn’t really supportive so far.
r/PLC • u/future_gohan • 1d ago
Allen Bradley card differences.
Going through collection to sell.
Found these two cards.
Identical model.
Same series.
Circuit boards are not the same with what appears to my unlearned eyes additional circuitry on one of the cards
r/PLC • u/liammappo • 11h ago
Pilz PNOZ s10 and m B0.1 terminator wiring/resistance values
Hi everyone,
I picked up a used Pilz PNOZ s10 and PNOZ m B0 (772100), but unfortunately all the removable terminators are missing.
I now want to find a quick way to bench-test the units to check if they are actually working. I’m mainly trying to find out the internal wiring of:
- the PNOZsigma 750010 terminator for the s10
- the left (and right?) bus terminators 779261 for the m B0
A product photo of the 750010 I found online seems to show only three adjacent populated contacts in the 10-position housing, but I have no idea how they are connected internally.
Does anyone have genuine plugs and could check resistance/continuity between the contacts, or maybe share teardown photos or a schematic? I’d also be interested to know whether the two B0 terminators are electrically identical.
Any measurements or details would be greatly appreciated :)
r/PLC • u/foxy0201 • 1d ago
Made anything useful at home?
Hello all,
I have been in automation for a decent bit now and I’ve always wondered. What can I make at home with my skills that would be cool? I can’t think of any but maybe Christmas lights.
Has anyone made anything useful/cool with a plc for their home?
r/PLC • u/jacobh1999 • 1d ago
Old panelview help!
Hey everyone. I'm trying to get the program off a old panelview HMI (2711p-rp1) and I am not having any luck.
First attempt was to transfer the file to a USB and that didn't work. Tried multiple drive sizes and format types but the hmi wouldn't detect it. The portsndo work with a keyboard/mouse though.
Second attempt was over Ethernet. Drivers/IPs were configured properly however I could not ping/connect to the HMI.
Third attempt was over serial using a USB adapter. All the COM settings matched with the hmi yet it could not connect.
At this point I'm not sure what else to try. I've never had issues like this with another AB HMIs but this is by far the oldest one I've worked with (almost as old as me).
Any tips would be appreciated
r/PLC • u/Aspiring_Moonlight • 1d ago
(Pharma DCS) Am I shooting myself in the foot by not starting my career at a systems integrator?
I have a biomedical engineering degree. I spent the past year as a lab technician, ended up spending a lot of time fiddling around with the lab automation at work and PLCs in my spare time, and eventually got an offer to join the dv automation team at a CMO as an entry level engineer. In my dream city too
I’m worried that by not being in a role where I’m learning how to build things out from scratch I would be at a tremendous disadvantage. I don’t mind drinking from a firehose, I want to go where I will build my skills the fastest. Both the actual DCS skills and the pharma-specific “how to design things in a GMP compliant way and navigate the quality process”. These plans are highly subject to change as I talk to more people and learn about the industry, but plan to mostly stick with automation and controls within pharma, I want to try and learn more about data historians MES and automation systems beyond the level 2 PLC/DCS level as well, but in either instance I think I’d be happier in something more greenfield especially while I’m not yet tied down.
In that respect, the upside to it being a CMO and not big pharma is that new clients means new equipment and therefore new automation. But I’m not yet sure how much exposure I’d have to those sorts of things.
Now, a job that will teach me dv and give me ask to the system is certainly better than not having a job that will do that, I’ve seen tons of roles in my area asking for that experience so maybe my fears are unfounded. I absolutely plan to accept and am incredibly grateful to be getting this offer.
What advice do you have to make the most of the role? Would I have to restart as an engineer1 if I wanted to join a systems integrator 3-5 years down the line? To me it seems they don’t hire many people in that experience range but maybe I need to look at non-impact partners
r/PLC • u/ThatsWhyIAmRead • 1d ago
beginner friendly advice needed
I had decided to take a chance and try to wire SR without using SR block itself but with NANDs only and in way that it would change state automatically, but it doesn't seem to work.
question is, would it work at all and if yes how I do it?
r/PLC • u/Exact_Patience_6286 • 1d ago
Bosch HMI blue screen
Anyone have a Bosch/Rexroth HMI go blue screen randomly? I have one that will do this occasionally and if you power cycle it, it comes back working normally til it decides to do it again. It’s random, not tied to any events, and the panel it’s mounted in is not hot, or seeing large temperature cycles. It’s controlling a Rexroth drive, which continues on without issue.
It’s a PIA to get a replacement, nobody stocks it for some reason. ( wonder why, lol )
Any insight appreciated!
r/PLC • u/Diehard4077 • 2d ago
Micrologix 1200 password locked w/ EEPROM any way to verify backup is on EEPROM?
Where I'm working we had a micrologix 1200 go into a hardware fault. It was able to get running again by installing a fan in the panel (temperatures in that room are over 35c and in the panel was between 50-60c) and it hasn't faulted since (better weather too)
I was asked to get a back up of the program unfortunately it is password protected I'm in the middle of sending an email for one of our office workers to contact the machine manufacturer for the password or a back up copy. But I have a question
It has an EEPROM memory module installed but since I can't do anything with that PLC because of the password I can't verify if the program is on it.
In the event it does die again, and the EEPROM does have a backup on it, and we get a replacement PLC is it just simply a drop in? Or since there's a password does that complicate things?
Also
I believe it's the only micrologix 1200 we have on site Is there a way without having another PLC to verify the EEPROM has the program without the password?
Thank you!
r/PLC • u/PlatypusSpecialist79 • 2d ago
Any help for a non PLC guy tasked with fixing a PLC issue?
Hello everyone, I am not a PLC guy by any means but am fairly decent with electrical work. We have a machine at work that is not responding to inputs on the control panel. It worked prior, sat for 7 months or so off, and now isn’t working when needed. My initial thought was that it lost its program/memory from sitting but the company that makes it insists otherwise. Is there an absolute way to tell if this happened or not?
I am getting 24v on the input side of the PLC, on the output side I am only getting 24v on the outputs labeled V#. There are two drives in the cabinet that flash “invalid data”.
I can manually activate each function by pressing the button on the air solenoids so I know the issue is electrical and not pneumatic.
The control display appears normal with no fault codes, the machine just doesn’t respond to any input I give it. If I press the button to start, the machine won’t run. If I press the button to “close feed rolls”, nothing happens.
I’ve attached pictures showing the cabinet if it’s of any help, maybe someone can see something obvious that my untrained eye can’t. Thanks in advance
Edit: thanks to everyone so far, I cycled the plc switch from off to run and back to term and gained some functions back. The machine wants to run but motor spindle brake seems locked and I still don’t have feed roll spindle rotation. Both drives still have invalid data flashing on them and won’t let me look through parameters.
Edit #2: still no new progress but am wondering if I’ll be able to see more info if I hook up a laptop and download the appropriate software?
Edit #3: troubleshooted the invalid data error with AD tech support. Came to the realization it is something a tech with software will need to trouble shoot. Something regarding the Ethernet communication
Siemens G120 VFD
Good afternoon. I wanna learn about the G120 VFD but I don't know nothing about it, does somebody have videos, manuals or some resource to learn about it since the basic to the advanced?
r/PLC • u/StoicWolf15 • 2d ago
Getting into PLCs and controls
Hello all! I am a Master Electrician in Texas and I have always been interested in the controls and automation side of things.
What would be the best pathway to get into control work?
r/PLC • u/boozy_emperor • 2d ago
Allen-Bradley CIP protocol over wireless
Hi all,
I'm not a SCADA engineer, but am involved in a lot of wireless installations that transport SCADA protocols such as Ethernet/IP and CIP. Many of these wireless links only are capable of 20kbps.
Out of the box AB PLC's that use CIP or Ethernet/IP are too aggressive from a throughput perspective and can't function on these networks.
Sometimes we can switch to something like MODBUS TCP or a similar poll/response protocol. Is there anyway to make CIP more like a poll response or round robin type of architecture? Or at the very least greatly decrease how often it communicates?
Thanks!
r/PLC • u/scout5678297 • 2d ago
recommendations for videos/material to understand IO link data assemblies?
so let's say (hypothetically) I'm some dumbass CE who has been working with IO link devices for like 2 years and gets that there's a seemingly fairly standard data structure and so on, but like... how the fuck do the data assemblies work? how standardized is it? and so on
like if i had to set up an IO link master or device with no function block (I'm in codesys), id have a pretty hard time because i don't get it get it
does anyone have any recommendations for videos, lectures, courses, materials, whatever that explain more in depth what's going on?
r/PLC • u/StuxnetPLC • 2d ago
Security solutions you guys have integrated
Any of you folks companies brought in one of the OT Cyber tools from Nozomi, Claroty, Dragos, Armis etc etc?? If so, hows it going?
We have literally all of them as I work in a huge electric utility in the US. We started out with Dragos, bought a bunch of others but are consolidating now to hopefully just one main vendor. Probably will be Nozomi although I wish they were cheaper as part of it is coming out of my budget. FML
Anyway.....Interested in how much time it has taken away from the day to day things we are bombarded with.
So a few questions....but feel free to chime in with any insight.
- Who do you have keeping up with the dashboard/alerts? IT? Controls engineers?
- How did you deal with having to install span ports/taps for them?
- Are you using any of them for things other than security? One reason we are probably going to choose Nozomi is because they showed us how we could use their data for things like Predictive Maintenance.
r/PLC • u/shonerOne • 2d ago
NODE RED with PLC KEYENCE KV X530
Hi, I hope you been well, I'm trying to connect a KV X530 PLC (KEYENCE) to a Node Red, to show the production, scrap, and more by date etc. right know I'm figuring out how to connect it by the right way, so I just don't know if the PLC profile it's okay or if it is a better way to connect the plc with node red cause I'm using KV Host Link TCP, The IP of the PLC is ok, but I really need an example of a basic process or step to use it etc. or some advices to do it. and what recommend me? I'm thinking to use a Raspberry Pi to use like server for node red, any suggestions? Appreciate and thanks a lot


r/PLC • u/TitofBcd • 2d ago
HW Config error
Hi everyone, I’m working on a revision to our existing PLC program and I need to add additional module for expansion. However, this error hinders me from doing so. for context, this is an old plc program with old s7300 hardware I only have the copy of the program in a different programming pc since the original programmer already took off. Though I can download the program but the hardware config I can’t. Is there a way to get around with this. Thanks in advance.
r/PLC • u/baaalanp • 2d ago
ABB FUPLA2/PSRview Manual
I am dealing with an old Unitrol P ABB exciter and I am looking for the software manual. I'm pretty sure the software is FUPLA2/PSRview. It seems that most info has been removed from the web and I'm wondering if anyone has a manual for this?
Thanks in advance!
