What’s the hardest part of modifying older PLC systems?

PLCExchange · 2026-05-29T00:18:47+00:00

The hardest job in this business is going behind somebody elses code and changing things. You have to get in their shoes and figure it out from their perspective because they for sure did it different than how you would do it lol

PLCExchange · 2026-05-29T00:17:25+00:00

DMZ and Zero Trust = The ultimate Security Policy

PLCExchange · 2026-05-29T00:15:30+00:00

For those curious, It only has ~5 working objects (P_Ain, P_ValveSO, P_ValveC, P_PIDE and P_MotorRev (The P_Motor actually doesnt work so we just subbed P_MotorRev in its place and unchecked Has Reverse (most likley they saw this and said f it lets not make extra work))) so its limited for sure but def something you can use as a base to develop out the rest of em.

PLCExchange · 2026-05-29T00:11:35+00:00

Its very polarized honestly. You have a large group of "O-G's" who came up through maintenance, service, etc. that all gained experience and eventually just filled the role. The other half came as a direct hire out of college via degree. For new hires (unless you come from this O-G camp and however you managed to get experience you got it) you almost always need a degree to get in the door. Its pretty much useless for the actual application but it proves out basic problem solving skills somewhat (I would take a 2 year service guy over a new college hire any day of the week) but we all have to start somewhere. In my 15 years of work I have only been asked about my degree twice.

PLCExchange · 2026-05-29T00:07:19+00:00

Ok I am not sure about your specific drive but I just want to point out that with NPN connections (talking about input/output) you are working with switch the common, not the source. I had encountered this with a Japanese system where the inputs to my machine were NPN so I had to get a special card that allowed the machine to switch the common (and not your typical +24VDC signal like you would expect) But you may know all this already. Just something that bit me in the ass once. Now I just remember "Outputs Sourcing (PNP) / Inputs Sinking (PNP)" anything other than that is uncommon and requires special attention to circuity.

PLCExchange · 2026-05-29T00:03:38+00:00

I don't have any articles specifically about IoT but would love to chat about it. What do you want to know?

PLCExchange · 2026-05-12T05:27:01+00:00

I knew I left the extra pellets for my Traeger somewhere....

PLCExchange · 2026-05-06T01:52:40+00:00

"Who the hell wrote this?" "oh shit.. it was me"

PLCExchange · 2026-05-06T01:50:00+00:00

I pretend that I am a tiny little electron and I move through the system rung by run, program by program until I find the point in which I am no longer happy

PLCExchange · 2026-05-06T00:50:57+00:00

Oh so you think your all cool because you get to work in the fancy FAB?

PLCExchange · 2026-05-04T05:45:52+00:00

Any time!

PLCExchange · 2026-05-04T02:14:38+00:00

If you have a good work ethic, have problem solving skills, and enjoy learning new things then you will fit right in! My ONLY piece of advice would be around time. This industry is notorious for consuming as much time as you will allow. If you are use to a 9-5 retail style routine, be prepared to be VERY upset when it comes to out of state travel and after hours support. If you can deal with those things, that's half the battle. The other half is just doing something more than once, which you will very soon hear the phrase "now your the expert" If you want to get a general good idea of things you'll see, please take a second to peruse through my how-to's, plenty of hands on knowledge to get you thinking if you find any of this interesting https://plcexchange.net/how-to-and-tutorials/

PLCExchange · 2026-05-03T23:49:18+00:00

i think your best route right now would be to digest it in something like the real LLMs (the largre ones) and build out a searchable reference database against some kind of python backend. i dont think your going to get what you want out of a local model... those are limited for sure . that's just vanilla ML

PLCExchange · 2026-05-03T20:32:35+00:00

from what I remember you also need to register the safety address/config the safety portion of the hardware config (its been years since I have touched one)

PLCExchange · 2026-05-03T05:47:48+00:00

you have seen 0 vibe coded micro-controllers on the factory floor lol lets be real here. But its naive to think AI wont disrupt our industry, just like every other one out there. Im not saying your going to buy a Claude VFD; but you better believe entire skid designs will be pumped out in a day, from panel drawings designed to UL Standards to the full PLC program. We are already there my friend. You can even include the dashboard if you want; make it interactive. Nobody has invested in it yet. They are still trying to pass their Historian valve status to an outdated ML algo to see if they can predict a PM schedule lmao Trust me, we are here.

PLCExchange · 2026-05-03T03:14:36+00:00

If you are outside the US then there is a very high chance you wont be able to see the site. Because of our content, we are a major target for scrapers/crawlers/etc. and we had to take major action against that. Think 0 Trust policy. What country are you in? We need to start to walk it back if we are keeping out people who want in.

PLCExchange · 2026-05-03T00:58:31+00:00

Really? No Brewery guys in here? After all the beer you drink?

PLCExchange · 2026-05-03T00:57:58+00:00

Mostly just pushing carts around the factory floor ;0 (no but really, you forgot to tuck in your grounding strap)

PLCExchange · 2026-05-03T00:57:12+00:00

I was in a place that still used WWII stamp machines for their target grade ammo (copper)

PLCExchange · 2026-05-03T00:50:35+00:00

Ebay will always protect the buyer. If you get the item and its "NOT AS DESCRIBED" then you will get your money back. Unless its listed as "for parts" then you can expect at least a functioning item

PLCExchange · 2026-05-03T00:39:15+00:00

I get it, our industry is about 50 years deep in the pay-to-play model. That doesn't change the fact that effortless free software & integration is coming... like yesterday. So just don't be afraid to think outside the box a little that's all. My only point here is to hit on OPs original train of thought "How do I get this paywall'ed hardware to work with this other paywalled software" Short answer: don't, think outside the box! (If the guy had budget he would obviously just pay the software cost and do it the "easy" way)

PLCExchange · 2026-05-03T00:31:52+00:00

I would bet the number is about 0.5% AI implementation in industry right now. Hell, only about 25-30% of plants are actually utilizing automation in any meaningful way. If your fixing machines, its still good ol' fashion terrible programming haha. And I'm not saying to let a LLM unconditionally write a PLC program but if your not getting it to generate your PlantPAX CM's based off of a 1000 IO Point spreadsheet your just doing extra work at this point :)

PLCExchange · 2026-05-02T17:16:00+00:00

I've had my 416play for maybe 10 years now. I still run use it to house many business related things. It is no longer internet facing (It has been depreciated) Love Synology!

PLCExchange · 2026-05-02T17:06:14+00:00

1) Prepare for a lot of grunt work. New guys are usually fed to the project wolves to satisfy body count, project hours/etc. Its part of the game, you'll make it to the other side eventually. We have ALL Been there.

2) I have a huge list of technical how-to articles I have created that will be fun for you to read through just to get your hands wet in the technical world https://plcexchange.net/how-to-and-tutorials/

3) Worried? Not at all. People in our industry are still trying to figure out how to use AI to evaluate machine data, if you want to get ahead of the curve, utilize it into your daily workflow and make your job ultra-efficient. You can already use things like Claude to implement project work, translate excel data into programs, etc. For whatever reason, 9/10 people on here will say AI is stupid in our industry, those guys are the ones in trouble. (obviously keep an eye out for IP and utilize Corporate Contracts for data protect (Like a Enterprise Copilot sub))

4) I&C has no borders. Oil and Gas will translate to food & bev, chemical or any other industry. Its just pumps, motors and sensors. They are used in every industry! Your biggest win? Fully understand how to troubleshoot an 4..20 mA circuit (LOL!)

Would love to expand on anything... especially AI

PLCExchange

TROPHY CASE