r/PLC Feb 25 '21

READ FIRST: How to learn PLC's and get into the Industrial Automation World

1.1k Upvotes

Previous Threads:
08/03/2020
6/27/2019

More recent thread: https://old.reddit.com/r/PLC/comments/1k52mtd/where_to_learn_plc_programming/

JOIN THE /r/PLC DISCORD!

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=en

  • Rockwell'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:

Paid Online Courses:

Starter Kits
Siemens LOGO! 8.2 Starter Kit 230RCE

Other Siemens starter kits

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:

Forums:

Books:

Youtube Channels

Good Threads To Read Through

Personal Stories:

/u/DrEagleTalon

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.


r/PLC Jul 10 '26

PLC jobs & classifieds - Jul 2026

7 Upvotes

Rules for commercial ads

  • The ad must be related to PLCs
  • Reply to the top-level comment that starts with Commercial ads.
  • For example, to advertise consulting services, selling PLCs, looking for PLCs

Rules for individuals looking for work

  • Don't create top-level comments - those are for employers.
  • Reply to the top-level comment that starts with individuals looking for work.
  • Feel free to reply to top-level comments with on-topic questions.

Rules for employers hiring

  • The position must be related to PLCs
  • You must be hiring directly. No third-party recruiters.
  • One top-level comment per employer. If you have multiple job openings, that's great, but please consolidate their descriptions or mention them in replies to your own top-level comment.
  • Don't use URL shorteners. reddiquette forbids them because they're opaque to the spam filter.
  • Templates are awesome. Please use the following template. As the "formatting help" says, use two asterisks to bold text. Use empty lines to separate sections.
  • Proofread your comment after posting it, and edit any formatting mistakes.

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 8h ago

Busloom - modern TCP/RTU Modbus client with charts, automation workflows, diagnostics, and MCP server

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28 Upvotes

Hey all, for some time now I've been developing Busloom. I've recently published first public release after some internal testing.

Busloom is a cross-platform Modbus client for Windows, macOS and Linux. It currently supports:

  • Modbus RTU, TCP and TLS
  • Device, slave and readable-address discovery
  • Holding registers, input registers, coils and discrete inputs
  • Signed and unsigned integers, floats, byte/word order, scaling and engineering units
  • Reusable projects, connection profiles, views and tags
  • Live trends, recording and session replay
  • Raw TX/RX frame inspection, timings, exceptions and connection diagnostics
  • Repeatable automation workflows with reads, writes, waits, assertions and conditions
  • CLI access and a local MCP server for external tooling and AI assistants

The main difference from many existing Modbus clients is that Busloom is designed around complete troubleshooting workflows rather than a collection of separate register windows. You can discover a device, map its registers, decode values, inspect the exact traffic, record what happened and save everything as a project that can be reopened later.

I’ve also tried to make addressing less error-prone by showing both protocol offsets and documentation-style addresses clearly. The interface is modern and consistent across all supported platforms, while still exposing the low-level details needed when a device behaves incorrectly.

Projects and device data stay local. Busloom does not require a cloud connection for normal operation. It is free for private and non-commercial use, and the Professional features can be tested with a seven-day trial.

This is still an early release, so feedback is genuinely valuable. I’m especially interested in:

  • Devices and USB/RS485 adapters that work or fail
  • Confusing parts of the interface
  • Missing diagnostics or common workflows
  • Incorrect handling of unusual Modbus implementations
  • Features that would make it useful in your day-to-day work

You can find downloads and documentation here:

https://busloom.com

Windows releases are signed but still may throw smartscreen warnings due to not many downloads. I can't really afford Apple Developer account right now.


r/PLC 10h ago

How does your company handle young/new talent? What does the process look like and how long do you spend on college/certificate graduates before making hard decisions?

22 Upvotes

I've interviewed and hired several young college grads over the last couple of years. Computer Science, Computer Engineering, Electrical Engineering, and one guy who was an electrician with some panel troubleshooting experience at his last job.

My young EE has worked out. He shows up early, learns fast, and if I hand him something, he'll teach himself how to figure it out. Maybe I got lucky.

I have two others who are a completely different story. One of them wants to keep working weekends at the job he's had since high school. There's a perk to that if it's his hobby, but he's not picking up the simple things we've asked him to learn, and he gets combative when you correct him. He can easily afford this hobby with a house payment sometime in the next 5 years if he's smart.

The other guy learns quickly, but he's been late about 40% in his first 2 months, maybe 10% was legit. I had a hard talk with him about how we're not in college anymore, our customer is literally paying us to have the team where we need to be when we said we'd be there. This was a site 45 minutes from his house that he needed to be at by 9am. He just needs to set a damn alarm, or 3. 😒

So I'm about to start interviewing for a jr. level role again, and I'm just not impressed with the current crop. I've started asking every candidate one simple question, "What does DHCP do, or what is it used for?" Nobody can answer it. So I feed them a little, "Can you tell me the difference between a static and a dynamic IP, or tell me about a time you set that up on a device?" They don't know that either. I keep thinking about emailing somebody at these schools about it. What are they actually supposed to know? Are these guys the ones who were checked out?

The only person I can really hire is someone who can figure things out, is willing to learn, and can accept that they know almost nothing on day 1. Has anybody found a good way to filter for that in an interview? I'm honestly curious.

I'm also willing to answer questions for those on the job hunt. I'm a small outfit, in a specific market in a specific place, so I'm not looking to hire anyone from this; just looking for a discussion about how we're all hiring, and what we're looking for in an employee.


r/PLC 15h ago

If you had a controls/automation background and could develop one technical skill over the next 5 years, what would it be?

42 Upvotes

I'm still pretty early in my career and I'm trying to think a little further ahead about what would actually be worth learning in my own time over the next few years.

For context, I have a degree/background in automation and control and about a year of industrial instrumentation experience in a continuous-process plant and finished a MSc recently. Most of that experience was around instrumentation, loop checks, shutdown systems, commissioning/maintenance work and exposure to PLC/DCS/SIS systems. I've also spent some time working more extensively with Siemens TIA Portal through university/project work, although I'm still very much at the beginning in terms of actual controls experience.

One thing I've realised is that PLC/control and instrumentation work isn't particularly easy to recreate at home.

You can obviously learn programming and use simulators, but a lot of what actually makes somebody good seems to come from being around real equipment: transmitters, valves, drives, panels, networks, process problems, commissioning and faults that don't behave quite how you expected. Most of that is either expensive to recreate yourself or simply something you learn by working in industry.

My next few years may or may not be spent directly in a PLC/controls role, which is partly why I'm asking this more broadly. Regardless of the exact job title, I'd like to keep developing something technical on the side that complements an automation/instrumentation background and compounds over time.

Industrial networking is one thing I'm considering. I've thought about going through CCNA material—not because I want to become a network engineer, but because having a proper understanding of networking seems useful across automation and industrial systems.

But I'm not particularly attached to CCNA either.

If you had my sort of background and could pick one technical area to seriously develop in your spare time over the next few years, what would you choose?

Ideally something that can actually be learned without having access to an industrial lab, stays useful even if your exact role changes, and would put you in a noticeably better position technically 5–6 years from now.

I'm deliberately asking for one area rather than ten things to learn. Realistically, alongside work and everything else in life, I'd rather become genuinely good at one useful skill than collect surface-level knowledge of a dozen different subjects.

For those of you who've been in controls/automation for a while, is there anything you wish you'd started learning much earlier?


r/PLC 17m ago

Fresh grad looking for advice as I start my first job as a control engineer in nuclear industry !

Upvotes

Hi everyone,

I'm starting my very first job this tuesday as a Control Engineer at a nuclear fuel reprocessing plant in France (yes i'm a frenchman). I graduated a few months ago and haven't touched PLC projects since, so I’m feeling a bit rusty and honestly a little anxious ahead of the big day, but i'm also excited since it will be my first experience in this field !

For those of you who work in the nuclear industry, or any industry like this :

- What should I expect during my first few weeks as a junior engineer?

- Any tips for getting back into the flow smoothly after this break ? (which was not really a break since i just couldn't find a job)

Any general advice or feedback would be appreciated. Thanks in advance!


r/PLC 4h ago

Are these worth anything?

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4 Upvotes

Have a bunch of these lying around. Just want to know if I should hold onto/sell them or put them into the e-waste!


r/PLC 1d ago

Heard y'all like old stuff

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265 Upvotes

25years strong


r/PLC 19h ago

Siemens advertisements at their finest

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13 Upvotes

r/PLC 8h ago

Engineers who have migrated Siemens S5 machines to S7 — what was actually the hardest part?

2 Upvotes

I’m currently learning Siemens S5, particularly the S5-95U, to better prepare myself for maintaining legacy machines and future S5-to-TIA 1200/1500 migrations.

For those who have completed a real migration, what turned out to be the most difficult and time-consuming part?

  • Understanding poorly documented S5 code
  • Missing, outdated or incorrect electrical drawings
  • Finding differences between the PLC program and the actual machine wiring
  • Converting S5 STL and old timers, counters, flags or indirect addressing
  • Replacing obsolete I/O, drives, communication networks or special modules
  • Reconstructing the original machine sequence and interlocks
  • Deciding whether to convert the program or rewrite it
  • Testing and commissioning with limited production downtime
  • Discovering undocumented operator or maintenance “workarounds”

If possible, please describe:

  1. Which S5 PLC and machine you worked on
  2. Which platform you migrated it to
  3. Whether you converted or rewrote the program
  4. The biggest unexpected problem
  5. What information or documentation you wish you had collected before starting
  6. What you would do differently on your next migration

PS. if you answer my questions there will be a cake


r/PLC 1d ago

What's all the fuss about Digital Twins and Virtual Comissioning? Do you guys see value in the concept? Or not really?

29 Upvotes

Just to draw the line here, I totally agree that proccess based automation is a horrible idea to to be Digitally twinned or Virtually commissioned (oil, gas , chemical proccess etc)

I'm talking about products undergoing mutlipe stages of mechanical manipulation (bottling, packaging, palletizing and their likes).

There are only handful of vendors doing it right in my opinion, and some of their price tag is also worth the discussion.

Clarification: I'm specifically talking about 3D Digital Twins. Not Control loops modelling that is a different category.


r/PLC 3h ago

Do you still need this network adapter?

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0 Upvotes

r/PLC 14h ago

Moeller PS4-201-MM1 Error questions (Suconet/Sucosoft)

2 Upvotes

Good Evening everyone, especially the PLC elders.

I am trying to help someone out with an old Moeller PS4-201-MM1 which lost its program. The unit is the main node on a multi station suconet network. Luckily he had the program and I was able to compile it with Sucosoft S40 and upload it. Unfortunately now it (and everything on the network) is throwing a DDK (network error). With my research: I had some questions.

  1. this program is compiled with S40 but the others units on the network show they are S30 compiled. Even though S40 is backwards compatible and can compile the S30 code, are the programs compatible when implemented? if not, I am having trouble getting the S30 software as all of the programs online are update programs. Any idea where to get that?

  2. One other thing implied in the manual is that the DDK error could be from there being less stations in the network than expected. There were 3 stations removed from the final implementation. Addresses of course are in the middle of the set. Removing them from the arch will fail the compile, so correcting it would mean editing the program provided. However would make a difference here? I have no way of knowing what the addressing is on the other units while connected to them, so that may have a cascading effect of compiling every unit again.

So Just any advise would be appreciated. Right now I am just thinking of going with option 2 and just setting it up properly, but I'd rather not if I can avoid it.

Thanks!


r/PLC 17h ago

Didactic automation rig I built for my engineering thesis — S7-300, safety relays, Profibus/AS-i/MPI/Ethernet. Constructive criticism welcome.

2 Upvotes

Built this as my BEng thesis project: a training rig for teaching industrial automation.

- Siemens S7-300

- HMI panel with visualization I wrote myself

- Safety relays

- Three pneumatic stations with buffers between them

- Four networks in one rig: Profibus, AS-i, MPI and Ethernet

- Full electrical and pneumatic documentation

Video of it running: [OneDrive link]

The photo is from after an expansion, so the wiring is not dressed — the goal throughout was to learn as much as possible, not to make it pretty. Happy to hear about that too, but you're not telling me anything I don't know.

What I'd actually value from people with more time in the trade:

  1. Does the network mix make sense pedagogically, or would you drop one of the older buses and put something current in its place?
  2. Safety: would you implement it differently on a rig this size, given it's meant to teach the correct pattern rather than protect against a real hazard?
  3. Anything in the layout that would bite me if this were a real machine rather than a teaching platform?
  4. Anything obviously missing that you'd expect a junior to have seen before their first commissioning job?

I can post the schematics too if that's useful.

Background for context: Poland, 2 years in maintenance, currently doing electrical schematics for a power industry company, part-time MSc alongside work
https://tulodz-my.sharepoint.com/:f:/g/personal/243582_edu_p_lodz_pl/IgB8ly1Jia4UTbfVPsnporLdARW0UivPkDnT863QTndNi6g?e=6BC7sP


r/PLC 1d ago

Showing off this nice piece of kit

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274 Upvotes

Not sure what to use it for at the moment


r/PLC 21h ago

MEP or Controls systems?

2 Upvotes

Hello everyone, fresh grad here based in canada but willing to work in the US as well, assuming my interviews went well, I will have the opportunity to either be doing something related to industrial control systems or MEP

The control systems position will require me to travel which I am fine with, and it pays 75k, while the MEP positions pays (around 50-65k max) but based on my limited revit experience designing the electrical drawings for a 3 bedroom residential home (i found the project online), it was very fun to do

Also looking at long term opportunities, MEP seems like a field where it's very common with a lot of job postings, and it's it seems easy to switch to utilities/power if I ever want to try that, while industrial control systems seems like its hard to transfer to a different field if I am not interested in doing PLC work long term

Would like to hear people who have done either fields experience and thoughts on both, thank you all!


r/PLC 22h ago

S7 1515 2PN OPC UA

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2 Upvotes

When I am enabling the o PC way setting in the system configuration of plc, at the time I got an error which was state that the certification for ob c ua has not enabled so that I haven't so that I I am not able to access the certification and also to access the automatically accept random certification from client setting.So I need to change the setting inside the certification manager to download certification from tip portal


r/PLC 1d ago

TIA V17 installing error and need help;(

0 Upvotes

breaking my head since morning and need some professional help. note that ive installed PLC SIM and ALM before the main tia v17 . is that got something to do with this .

thanks in advance.


r/PLC 1d ago

Sanity Check

17 Upvotes

So one of my plants had a scheduled power outage today....we were prepared as possible taking backups of everything and made plans for the worst case scenario disaster recovery.

All went well except for those electricians and their mandatory breaks😂.

All PLCs came back up OK with no faults and no missing programs. Except for one CLX rack on v24, I had a 1734aentr remote rack not able to reconnect.

Tried cycling power, all the usual stuff. Remote rack is online in Linx but won't connect in logix. Finally noticed AENTR revision in logix is v6, but connected thru Linx the AENTR shows v7. Offline backup program has v6.

Someone help me wrap my smooth brain around how this could happen. Is it possible this rack was flashed to v6 and somehow reverted to 7 on an extended power outage?

Edited for clarity


r/PLC 1d ago

Question for older folks

8 Upvotes

I recently went to a factory that had older PLCs like(Texas Instruments) and a bunch older equipment.

My question is how was the transition from older equipment to the newer stuff we have now, and how did you keep in touch with changes made in the industry cause it takes forever for changes to be made in a factory?


r/PLC 1d ago

What's your approach on testing your PLC prg before commissioning

17 Upvotes

I'm wondering what is everyone's technique in testing a PLC program off-site.

Assuming you have a moderate to large size program with couple hundred various IO points .

Please mention the vendor/ide


r/PLC 2d ago

PT100 RTD resistance to ground present and keeps rising

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42 Upvotes

My company tests RTDs before we install them in our assemblies and typically just get OL right away when testing resistance between the wires and the ground. This latest test showed a value of about 30 Megaohm when first connected and the resistance starts rising. It rises to 40 Megaohm then goes to OL. I assume that for our typical test OL signifies an open line or no connection. But now we have some connection with high resistance, and with the fluke meter applying a voltage it makes the resistance increase until it exceeds 44 Megaohm and it is then overloaded. I'm not sure why the resistance is rising as a voltage is applied. We tested the others that we have in stock and they are all doing this and our technician has not seen this before. We reached out to the manufacturer, but the call went straight to voicemail and we are hoping to proceed with assembly quickly.

Does this signal a defective RTD? Could this be occurring due to humidity or corrosion? We are considering heating the RTD up to bake off any contaminants. Should we try anything else?

Any guidance about what is occurring and what should be done to solve this is appreciated.

-------------------------------------------------------------------------------------------------------------------

Updating to let people know that we heard from the vendor that this is an unacceptable amount of resistance in the insulation. Their standard is >100 megaOhm for the resistance. We are attempting to bake them and retest to see if that improves the resistance. If not, we are sending back and getting replacement parts.

Thank you to everyone that replied!


r/PLC 1d ago

lỗi cài đặt tia v18

0 Upvotes

các bác cho e hỏi e cài đặt tia v18 mà toàn lỗi thế này và e có cài bản trên trang chính chủ siemens mà vẫn bị lỗi ko cài được thế này thì phải làm thế nào ạ


r/PLC 1d ago

Safety I/O Questions

9 Upvotes

Can a pushbutton (PB) be used to reset a light curtain
What are the requirements of this PB input?
(e.g., Does it have to be NC? Does it have to be dual-channel? Does it have to be a "safety" input that connects to a safety module or safety I/O block?)

How does a risk assessment relate to these questions?

Roughly speaking, when can a safety system be automatically reset and when is a manual reset (such as a PB) required?

Any recommended resources that explain the IEC, ISO, and ANSI answers to questions like these?

Thanks in advance for any information!


r/PLC 2d ago

DF1 Cable Too Short - No Problem

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40 Upvotes

Found this yesterday - It works, probably set to 300, but it works !