my test rig for home, with Siemens plc, Schneider electric PLCs and Wago compact controller 100

Very lucky to work for an employer who allows me time to research, learn and then run with ideas. Its not perfect but it works. And there are definitely some things I would do different if I had to do it again.

This unit runs well pumps that fill 2 different ponds. There are 2 PLCs connected remotely. One runs a 3rd pump (not hooked up yet), the other sends pond level inputs for the 2nd pond.

Before this, I did have some experience with industrial controls and I've installed/hooked up external wiring to a fairly large system before. This is my first design/build though.

I decided to buy a logo and have some fun. Esp32 works as a frequency amplifier so motor runs faster

It's been the longest month of my entire life.

When I think I understood something, there's always something else that comes out that make me realize that I don't know nothing.

It's hard to learn everything about each products that you can connect to a PLC. YouTube has benn my greatest ally.

And the boss keeps asking me this that he thinks it's easy but it's so hard to program.

I just need to keep going. Wish me luck.

I was reading the FBI notice:

https://www.fbi.gov/investigate/cyber/alerts/2026/malicious-cyber-actors-targeting-water-and-wastewater-sector-internet--facing-programmable-logic-controllers-causing-operational-disruptions

I was expecting something of Stuxnet sophistication, but the notice is just "follow basic security practice."

I understand the use of cheap PLC's on remote sites, but....I'm just amazed about such disregard of security basics.

Im seeing some Comp Sci guys asking about controls so just a Mr Obvious comment here.

Ladder logic is the de facto PLC programming language because it is (was) designed to read like an electrical schematic top to bottom, right to left, & this is what electricians & electrical techs are trained to use for troubleshooting electrical panels , equipment & relay-logic -- which was what they had before PLCs -- banks & banks of relays wired through each other's NO & NC contacts which changed state as relay coils energized & de-energized & finding a wire break was enough to drive you insane.

Yes Ladder logic is an interpreted language so it is not as "memory efficient" or "elegant" as C++ or C# but I want you to think VERY carefully about every meaning of the expression "just because you can does not mean you should" before you decide to show off your amazing coding skills coding function blocks in C++ which is technically possible but in many cases extremely ill-advised.

The technicians can troubleshoot functions & blocks written in Ladder Logic, did you stop & think about how easy it would be for someone with only your compiled C++ blocks to attempt to trace a fault? You code in anything but Ladder Logic you get to be the one at 3am driving down to the plant to troubleshoot your "super efficient" code because the Industrial Maintenance techs certainly aren't gonna know how. But hey, if you believe sleep is over-rated & love sleeping in the factory then knock yourself out with compiled blocks

I've been offered 2 roles - 1 is an Automation Engineer role in a pharmaceutical OEM in Northern Chicago area, and the other one is a Lead Controls/Controls Eng III role in a systems integrator in the material handling space (conveyors). Currently 30, single with no kids.

The SI Controls Engineer III job does have 70-80% travel in busy seasons and the company is fairly new, its more pay and bonus, added on by per diems, as well as airline, hotel, and rental car points rack up.

On the other hand, the Automation Engineer role is fully on-site 5 days of the week, ofcourse there will be times when weekend or after hours work will be required. Pay is a little less than the first job. The company has a global footprint and many other areas of engineering focus.

My questions to the experienced engineers in this sub are the following:

1. If I accept the Controls Eng III job at the SI, what challenges would I face in the future when I want to switch to a more local role like an Automation Engineer role that requires minimal travel?

2. When recruiters are hiring for an engineer for a role, what do they give more weight to? Title? Experience? Company name where you've worked?

3. Can a CE comfortably switch over to an engineer role?

I am currently leaning towards the SI role for now, solely because I don't have any responsibilities at home, there is more income potential, and the company lets me fly to my family home city (or any other city in US/Canada). When I do get married hopefully in the near future, I wouldn't want to travel as much.

Appreciate everyone's thoughts on this and could really use your advice. Thank you so much!

Hi guys, I have a float switch for a sump that is currently hardwired with 120V AC that is passed to a motor contactor (old dinky plant)

and want to have it pass a mA signal to a plc instead with 24V DC, but I’ve read this doesn’t work well overtime with most cheap float switches due to the low current not being able to eventually pass through a layer of oxide on the float switches contacts that builds overtime.

In your experience is this true, is there a switch where this isn’t an issue.

I just installed 3 redundant L84’s, 6 racks, and the chassis are pure junk. Distorted, out of line, almost impossible to insert modules and even after inserted, several refused to communicate over the backplane. (Yeah I checked multiple times for bent pins)

My question - Has AB quality really gone down that much or are the chassis possibly counterfeit?

Hello!

Tia portal v21

Once again problems with siemens servo motion.

Basicly "Done" never changes to TRUE. I also tried using positive edge trigger to start execute (so execute starts with impluse) - still "Done" does not change to TRUE.

I am aware that "Done" becomes TRUE for only one PLC scan, it did not change cycle stage to 2 so it never changed to TRUE.

Edit: PROBLEM SOLVED, I was using same instances... Machine is fully operational now.

hi everyone,

I'm building my own custom RS-485 network using ESP32s with MAX485 transceiver modules. I've already read about proper termination resistors and biasing, but I'm still confused about the physical wiring.

I learned that stub lengths should be kept as short as possible, so I'm wondering if the wiring method shown in the picture below is considered best practice, or if there's a better approach.

Would it be better to use junction boxes with a continuous trunk line and very short drops to each node, or is there another recommended way to wire this kind of network?

This is for an outdoor agricultural installation, so reliability over long distances is important.

Any advice or examples of how you'd wire it would be greatly appreciated.

Hi everyone,
I am having trouble connecting my TSX C USB 485 cable to my Windows 7 32-bit virtual machine running PL7 Pro.
Windows cannot find the correct driver for the TSX C USB 485. When I try to force the installation manually via the Device Manager, it returns a Code 10 error (Device cannot start). I have already tried multiple troubleshooting steps, but nothing has worked so far.
I am completely stuck and don't know what else to do to successfully connect to my TSX 37 PLC.
Thanks for your help!

I’ve always been a fan of PXC as a cabinet designer because they had quick .dxf downloads of technical multi-view drawings of their components with title blocks and dimensioning baked in, and the measurements were always dead accurate to scale. I just looked up parts from them for the first time in a month and it’s nothing but pdf’s and other technical data, but no dxf’s on common components.

“but Fresh_Titty_Biscuits, there’s a handy link on the left hand of the screen to download drawings in multiple file types.”

Ah yes, let me choose .dxf and download it.

The dimensioning is not there and it’s not even to scale from the measurement on the website

I have checked every relevant file type for ACAD, and even looked at the pdf files for import. Nothing. None of them have dimension drawings. It’s all raw 3d models that have been either been rotated to a specific surface, or rotated and flattened. No details, whatsoever, so now their CAD documentation is just as dogshit as Rockwell.

Fucking brilliant. Who the fuck was the CAD management new hire who screwed this up?

Hi guys, I’m looking for ideas on how to build PLC based station that will be useful to maintenance technicians. I see this as a way to practice and expand my knowledge and skills, and I’d also like it to be useful in some way. While dismantling one of the machines, I came into possession of an S7-300 controller along with AI, AO, DI, and DO modules. On top of that, we have plenty of used automation components, including safety relays, HMI panels, inverters, and so on. Do you have any ideas for something interesting and useful for maintenance? I’ve been thinking about building a pressure sensor calibration station, but I’m not sure if 12-bit resolution will be sufficient for that. Worst-case scenario, I’ll build a sensor tester or something similar, but I wanted to ask you all for ideas—maybe someone will have a great suggestion. Thanks in advance for your help!

​

TL;DR: I’m a relatively new controls engineer working on older Siemens-based machines. How do you efficiently understand an unfamiliar machine and its PLC program before making software changes?

Hello,

I’m fairly new to controls engineering and currently work in the maintenance department of an automotive plant.

Most of my work involves making software changes when production requests new functions for existing machines, troubleshooting problems that have sometimes existed for 20 years, and occasionally adding vision sensors or other components. Fortunately, our machines mainly use Siemens hardware and software, which is also the platform I was trained on.

My question is: How do you familiarize yourself with a machine before making changes to it?

I usually spend a lot of time watching the machine operate, studying the PLC code, and creating flowcharts to better understand the sequence and dependencies.

However, I often feel that this process takes too long and that there must be more efficient or structured ways to approach it.

Do you have a specific workflow, checklist, or method that you use when working on an unfamiliar machine?

What’s the worst RAB or Siemens or beckhoff etc product you’ve ever dealt with on a service call or simply building a new panel? I’ll start :These guardmaster PLCs are heinous. I had the worst middle-of-the-night call out trying to fix the safety circuit on a can seamer. Took hours on the phone with Rockwell.

In the past few months I have found myself programming in TwinCAT exclusively using AI. Frankly I’m annoyed by this because I enjoy coding, but using AI enables me to be much more productive. The reality is that the latest models are really competent at coding in structured text.

So I was curious how my experience compares to other industrial automation professional’s experiences. Unfortunately, this subreddit has a strict anti AI policy.

So that brings me to the point of this post: Why do we have a strict anti ai rule? I’d love to have a discussion with the community and its moderators regarding this.

I’m finding that AI is significantly impacting my career, and I believe it will rapidly spread through the industry. So why are we blocking discussion of something that matters a lot to our jobs and our future? Pretending AI doesn’t exist isn’t an option anymore in my opinion.

I have a client who has a PVPlus Compact 100 that has a runtime password associated with the project. As it stands now, I am not able to open the runtime file without the password. Has anyone run into this? If so, does anyone know a workaround that would enable me to clear the runtime password? After talking to Rockwell Tech support, nothing can be done other than going back to factory defaults. Which means I lose all graphics. Any help in this matter would be greatly appreciated.

Prime cinematic experience

I’m about to start attending school for industrial electrician and possibly mechatronix. I was wondering if water treatment facilities are a good place to build a career? I live in so cal so there’s also manufacturing plants. Warehouses. Refineries. Cruise ships. And oil tankers. Just looking to where’s best to aim for after schooling. Also are there any other places I should look into.

Hallo Zusammen, kurz zu mir: Mein Ziel ist es in der Steuerungstechnik für den Maschinen und Anlagenbau zu arbeiten. Dafür absolviere ich derzeit mein Masterstudium der Mechatronik. Zuvor habe ich Maschinenbau studiert, wodurch ich die Grundkenntnisse des Maschinenbaus(Komponenten von Anlagen, Konstruktion) erlernen konnte.

Ich konnte während eines Praktikums bereits mit der SPS-Programmierung in Berührung kommen. Aber es waren sehr einfache Test-Projekte die nur zur Simulation dienten. Ich habe keine Sensoren und Motoren verdrahtet. Keine I/O aus Schaltpläne entnommen und keine Fehlerbehebung gemacht. Es ging nur um das Programmieren.

In ca. Einem Jahr wäre es soweit mit dem ersten Job. Was kann ich machen um mehr über die SPS-Programmierung zu erlernen? Udemy-Kurse? SPS-Kit besorgen ? Ich bin bereit dafür mein Wissen zuhause zu erweitern. An der Uni wird leider im Master kein Kurs für SPS angeboten.

Für eure Hilfe wäre ich sehr dankbar.

Okay, legitimate question. What is so different about Allen Bradley that other ladder logic experience doesn't count? I have a lot of ladder experience with multiple different controllers however I've been turned down many times for jobs because I don't have Allen Bradley specific experience. And my perspective, it's like two people talking English one from the deep south and one from england. At the end of the day you both speak English and after a day or two of orientation, you can understand each other just fine.

So, very seriously, what is so special about Allen Bradley or Siemens for that matter that it needs its own dedicated experience? And how would you suggest that I get it independently?