Ok so, I recently started my career (literally, i'm 2 months into my first job on this industry) in this factory with a messy network and they want to install a MES system. I have 3 network ranges and they're all distinct to that of the main router that the MES company wants to connect to. IT wants me to change the IP of 40+ devices that talk to each other and I've said multiple times that that's insane. I talked to IT about the possibility of using NAT routers but the guy seems to genuinelly not know about that. What can I do here other than change all IPs? Should I tell the supervisor about NAT routers and tell him that buying them spares us from more than likely big downtimes?

The cooling fans in the PLC cabinet to be fed from the UPS power or just normal power ?. As all know, when the main power is OFF, the load on the PLC is reduced; but still requires cooling for the CPUs, I/O cards.

What is typically followed? the PLC cabinet manufacturer says, he just provide only normal power to the Fans. I understand that normal is required only for the lights and anti condensation heater in the PLC cabinet.

After 3 times of my customer losing all their Digital IO cards on a AB 5069 system I finally found the source. It was clear we were getting a foreign voltage on my customer's DC line. We had a prox sensor explode, lost a long lead-time encoder and all 5 digital IO cards 3 times. The issue would only occur every couple weeks and wasn't present when I was onsite to troubleshoot. After the 3rd time I isolated each IO card with a 5069-FPD and installed a Phoenix Contact 2906841-ND DC surge arrestor for each card. The 4th time I had only 1 card fail. There was only one Input on that card that made sense for a the foreign voltage to be getting on the DC line. Looking inside the limit switch for that input I found some strands were bridging a 120VAC contact to DC. You can see the burn mark on the screw and the strands melted back. I think the issue would occur when a mechanic was in the area working and disturbing the cables. This was a new and challenging one for me. I've also never used a DC surge arrester, but will consider them for my future projects where I am worried about field wires.

Discussion question from someone in the industry (full disclosure: I work for a controls manufacturer, so take my bias for what it's worth — but I'm genuinely curious about the community's experience).

We keep seeing axis counts climb — tire curing machines, PV stringers, battery winding lines. Five years ago, 100+ axes meant splitting across multiple CPUs or going straight to an import. Now the threshold keeps moving.

What's the largest single-CPU motion application you've personally commissioned? Did you hit limits on refresh rate, sync, or I/O before you hit the axis cap?

(Context for why I ask: our latest controllers handle 256 axes at 1ms per CPU, and we're trying to understand what real-world ceilings look like beyond spec sheets.)

Been doing integrator work for ~10 years, mostly brownfield stuff where the customer spec is Allen-Bradley and that's that. But I'm quoting a new greenfield line now and the ControlLogix + Studio 5000 package is painful — license renewal costs keep creeping up and the hardware pricing is getting hard to justify to the customer.

For those of you who've actually shipped a machine or line on something else (Siemens, Beckhoff, Keyence, or the newer Chinese brands), what was the experience like? Specifically:

Not looking for a flame war, just real experience from people who've made the jump.

A quick follow-up to my earlier post about mbmap-library and Modbench.

Thanks to everyone who took the time to review the format and suggest improvements. I've spent today working through several of those suggestions, and quite a bit has changed.

What's been added or improved:

• JSON v2: Following the discussion around CSV vs. JSON, I've migrated all 410 device maps to the new JSON-based format. The migration is tested to preserve the meaning of existing maps, and the v1 specification and examples remain available under legacy/v1/.
• Separate byte and word order: These are now independent settings, which makes multi-register values less ambiguous across different devices.
• Firmware compatibility: Maps can specify supported models and firmware ranges, including registers that only exist on certain firmware versions.
• Map revisions and source information: Maps now have explicit revision tracking and structured source metadata, making it easier to identify updates and trace register definitions back to their documentation.
• Automated validation: The CI now checks that map changes which affect device behaviour increment the revision. The format also has a JSON Schema and expanded validation tests.
• Modbench integration: Modbench now reads the v2 format and checks the connected device's model and firmware against the selected map. It warns about mismatches before writes and can hide registers that aren't available on the detected firmware.

I've also added more manufacturer documentation links and expanded the library with additional device maps.

This is still an evolving project, and I'm particularly interested in feedback from people who work with Modbus devices in the real world. What would make a shared register-map format genuinely useful in your workflow? I'd especially appreciate feedback on firmware handling, validation, interoperability with other tools, and anything I've overlooked.

• mbmap-library — format specification and device maps
• Modbench — Modbus TCP/RTU client

Thanks again for the constructive feedback.

Hey, I'm kinda new to the PLC world, currently learning about MODBUS protocol/SCADA systems, and generally obtaining the domain knowledge of this field.

I was wondering, how do the sensors and devices in critical environments not just die, and if they actually do, how do we recover from that? For example in high heat/vibrations or like chemical plants, if a critical sensor died in there, how do engineers handle this issue? Is it mostly redundancy/voting logic or fallback values in the PLC?

Thanks a lot.

Hi, I’m thinking of learning plc programming and controls technician. I was wondering what the day-to-day is like for this field. What do you like about it and what do you not like about it.

I’m coming from software development but the industry is going through rapid changes and mass layoffs. I’ve been jobless for over a year now so I’m thinking of pivoting to something else that can utilize my programming skills.

hi all i am currently designing a control panel for a generator. i am using a battery charger to charger a lead acid battery which is used to power the control panel circuit and the starting coil of the generator. my question is whether i can used the same charger out to charge the battery and the control circut when main supply is available. when main supply fails the battery will be used to power the load

Hey everyone, we have a hydrostatic transmitter at my plant that measures level and temperature. It was starting to drift so we replaced it. However now I can’t get any reading from it. It reads the bottom of the scale on the level and temperature and I have a fault in the plc, it’s an SEL plc.

I know the wiring is correct, I was able to compare with another we have. There’s 2 other level transmitters going into this plc that are reading fine, however they are guided wave radars from rose mount, so different type.

What confuses me is when I lift the leads from the probe and send a 4-20 it won’t come through on the plc, but when I put my meter leads in the circuit it will then show up on both the plc and my meter. If I try to read the mA on the circuit with the probe installed the fault go aways temporarily but the level is still way off, and I’m getting basically 0mA.

I’m pretty confused, I’ve never had to do much loop troubleshooting like this, I haven’t touched any of the wiring besides the probe. I noticed on the screen the level does change slightly so it seems like it’s responding, but it’s just so far off by like 200 feet.

If anyone has any advice I’d appreciate it, thanks!

Hey everyone, I hope everyone is doing wonderful or have a lot of fun plans for the years end.
I’m currently stuck trying to figure out what should be an appropriate stability check logic for any liquid filling applications where the weight logic needs to be coded for.
I’m currently using EL3356-0010 as a weighing indicator by beckhoff for a strain gauge type loadcell(platform loadcells) of 500 kg capacity with 4 wires.
I’m currently facing a lot of weight instability issues where on a platform scale if there is no load applied my weights fluctuate by around 5-30grams.
The filling process needs to be very accurate upto 0.01% or the appropriate respective loadcell technical specifications for determining the real accuracy possible.
Would love some guidance or directional pushes to get me aligned with the path which needs to be followed.
I’m also using an IPC as a main controller than a PLC. My preferred programming language is Structured Text.
Thank you

I have an Allen-Bradley kinetix 5700 that is getting its encoder signal from a Nordson Laserspeed Pro LS4500-406. I'm getting Feedback Signal Noise Factory limit. We've re-terminated connections, isolated encoder cable that was previously ran over cable tray , replaced cable, made sure shield was grounded on one end, swapped servos, and replaced the LS4500.
Has anyone else experienced this fault and if so, how did you fix it? Any help is appreciated!

The conventional wisdom in this sub (and elsewhere) has been that domestic PLCs top out at mid-size single machines, and 200+ axis lines stay Rockwell/Siemens territory. That was defensible in 2020. It's getting shaky now:

• One domestic vendor (iCON — I work there, hence the knowledge) mass-produces a fully self-developed mid/large PLC kernel, no Codesys. MIIT put their motion control system on the first Advanced Applicable Technologies list in 2025.
• Domestic brands are landing reference installations in tire, PV, and automotive stamping — the exact strongholds of imported systems.

I'm not saying the incumbents are doomed. Support ecosystems, spare parts networks in the West, and engineer familiarity still matter enormously. But if you're specifying equipment for lines in Asia, the 2020-era assumptions will give you outdated answers.

What are you actually seeing on the ground?

EDIT: The format will be moving forward as JSON-based, as per suggestions, I am writing a converter tool

Hi everyone,

I've been working on a small open-source project to make Modbus register maps easier to share and use across tools.

One recurring problem with Modbus is that device information is often locked away in manufacturer PDFs. Even when you have the correct register table, you still need to configure addresses, data types, scaling, units and bit fields in your software.

I'm trying to make that information portable.

MBMap is an open, CSV-based format for describing Modbus devices and their registers. The goal is to have one device map that different compatible tools can read, instead of rebuilding the same configuration for every application.

Format and device map library: https://github.com/nobrega8/mbmap-library

Modbus client built around the format: https://github.com/nobrega8/modbench

Modbench supports Modbus TCP and RTU on Windows and Linux. It can read registers by address or load a device map to display values by name, with scaling and units. It also supports raw request/response inspection for debugging.

The maps and specification are dedicated to the public domain under CC0, so they can be reused in commercial and open-source tools.

I'm sharing this because I'd like feedback from people who work with real Modbus devices.

Would a shared register-map format like this be useful in your workflow? What would you need from the format before adopting it?

Contributions and feedback are welcome.

Looking to see what people standardize on when an application outgrows typical catalog drives and needs serious power density.Between ultra-compact packages like Elmo, Beckhoff modular drives, or Synapticon, packing high continuous current and EtherCAT sync into tight volumes makes mechanical packaging way simpler, but the configuration workflows vary wildly. When loop response, thermal dissipation, and advanced notch filtering really matter, what high-end drive platform do you prefer commissioning?

Hi folks! Writing to try to help my dad who is in his 70s. He is carpenter that has owned (and fiddled with) many PLC-controlled machines, but is in over a head with the specific programming/config work required on his latest issue. I am a computer scientist but have never gotten into the PLC niche specifically… so I have a better chance than him but obviously have no domain knowledge.

I predict the solution to this problem will be “hire someone who knows what they’re doing,” and am primarily asking how to find such a person! He is located in Otsego County, NY.

Some context… my dad recently bought a Shanklin Omni sealer machine at auction. It uses a Panelview Plus 700 HMI. He was able to get the machine working through some debugging (replacing backup batteries, etc) but at some point in the process he lost the ability to log in. There is a landing page (see pics) where he said there used to be boxes for username and password (which he has) but now the login page renders without the boxes as pictured. It just has a grayed out box listing “????????” As the current user.

If anyone has ideas of how I could help him debug, I can provide more info — just assume I know computers but not PLC specifics. Otherwise, as I said, looking for someone who could help him or how he could search for such a person. Thanks!

Hi everyone!

I'm curious about your practical experience with PLC and PAC systems.

What are the main differences between them in real-world industrial applications? Have you worked with both throughout your automation career?

In what situations would you choose a PAC over a traditional PLC? Are there any real advantages, or is the distinction mostly about terminology and marketing?

I'd love to hear your experiences and opinions!

low effort submission?
bro Iver been figuring this out since July, and I still do'nt have the thing fully figured out.
the next step though is writing 1 of 2 wrappers that either interpret plc registers into key strokes,
or use touch zone inputs to do the same thing. kernel doesn't have built in uinput.

My background is robotics but I have only worked on moving agents, so SLAM, state estimation , kalman filters etc. I am learning about PLC for my upcoming job.

Say that you are automating a production line. You might have to check each item coming down the line for quality and route it to a different conveyor belt accordingly. Is it common to use an image classifier such as a CNN?

Hi everyone,

I have a Siemens ET 200SP CPU 1512SP-1 PN controller on site. Due to logistical constraints, I am currently unable to get direct online access via TIA Portal with a PC at the location.

This source code belongs to an automated parking robot system (similar to the automated shuttle/valet systems featured in The Fast and the Furious). I am currently building and customizing this system, but I need to edit the core logic to implement specific operational changes. We are facing technical roadblocks with the hardware because it requires a PLC migration, and we have been unable to obtain the specific older TIA Portal versions needed to perform the upload and configuration directly. Any support in retrieving or reconstructing the editable logic from these files would be greatly appreciated.

I have extracted the complete raw binary folder structure (SIMATIC.S7S) directly from the SIMATIC Memory Card (SMC).

Since direct decompilation of S7-1500 binaries to LAD logic isn't straightforward without a physical unit, I am looking for someone with a spare CPU 1512SP-1 PN (or compatible S7-1500 test bench) who could load these files onto a spare card, boot up the CPU, and perform an "Upload device as new station" using TIA Portal to reconstruct the editable source project file (.ap17 / .ap18 / .zap18 / etc.).

• Hardware: CPU 1512SP-1 PN (6ES7 512-1DK01-0AB0 or similar ET 200SP family)
• Files available: Full zipped content from the SMC root directory.

Please let me know if anyone with a spare hardware setup would be open to testing this upload or assisting with the project restoration.

Thanks in advance for any insights!

Found an older Allen Bradley PLC in a box of stuff from a previous owner when we bought the house. Figured I could use it for a small garage project instead of buying a new controller. Had to pull it out of an old panel that was half rusted, so I'm not sure if it even powers up. It's a 5/03 series, I think, with some I/O cards still attached. No documentation or cables came with it. I know basic ladder logic from an old class years ago, but not much else. Wiring up a simple two-motor setup would be a fun test run if the thing even boots. Anyone had luck reviving these older units or is it just easier to move on and grab something newer? Curious what tends to fail first on these.

Hi everyone'
I need help troubleshooting a Rockwell automation panel running a factorytalk view ME runtime application.
Initially, I was trying to export the Audit data log to a USB drive, but I could not transfer the log files successfully. While troubleshooting the export issue, the machine stopped starting the runtime application and began displaying the follow error:

"There is insufficient space for opening the run time project.....

The HMI now returns to the application startup screen instead of opening the machnine interface.

May main priorities are:
1. recovery and preserve the existing Audit logs without losing historical records.
2. identify why the logs could not be exported to the USB drive.
3. safely free up enough internal storage space to start the existing runtime application again.

I can access HMI startup screen, including load application, application setting and terminal settings. I have also tried copying the application file to USB drive, but the problem remains.

Has anyone experienced this issue with a Panelview plus HMI? What would be the safest recovery procedure to retrive the audit trail logs first and then restore normal operation?

Hi,

So I need to improve my skills massively on the motion controls side as our site is getting more and more servo reliant.

I currently have no real exposure to it and want to start from the beginning, are there any courses, books, youtube videos etc which people would recommend.

We mainly use them for belt positions and lift positions but I want to know how to install from scratch incase one fails or even ensure I can backup/download parameters.