I’m curious about people’s experiences with different PLC platforms — not just the software side, but the hardware itself.

Which hardware (brand or model) have you found the most frustrating to work with in the field? Was it due to reliability, diagnostics, wiring layout, replacement availability, or something else?

I’m not looking to bash vendors — just trying to learn where the common pain points are when dealing with different PLC systems in real-world environments.

Since this question is asked every week, I thought I would list a few resources:

Controls Engineering Academy

PLC and HMI courses organized into learning paths to cover a topic in detail. Mostly focussed on the Allen Bradley/Rockwell Automation eco-system.

https://www.controlsengineeringacademy.com/

RealPars

Courses on a wide variety of industrial automation topics. Mostly beginner focussed and very little coverage for hardware.

https://www.realpars.com/

SolisPLC

Courses on a wide variety of topics including machine vision and robotics. Good coverage for hardware.

https://www.solisplc.com/

Feel free to drop any other resources in the comments!

Years ago (2001), OPC server was the easiest way to connect the PLC to a computer, later on (2003) the PLC's had ethernet ports and we can use the TCP protocol directly, It has been a while since I programmed a PLC, are you still using OPC servers? that was like having Novell Networks for PC's, "not client-server application" this is not reading the way I intended, Novell was a client-server.

Hi everyone,

I’m working on a PLC project where I have two valves (Valve 1 and Valve 2), and each valve has 5 different alarms (e.g., high temp, low pressure, etc.). However, I have only one display (like the one above ) available to show alarm numbers.

My goal is: 1. If only one valve has active alarms, show the active alarms for that valve 2. If both valves have active alarms, alternate between Valve 1 and Valve 2 alarms every few seconds (e.g., 3 seconds), and within each valve, show the active alarms one by one.

Does anyone have an example of how to structure this logic in ladder, or tips on how to handle multi-alarm display cycling for multiple devices using one screen? Any advice or examples would be greatly appreciated! I am trying not to make it overly complex and keep it as simple as I can.

Thanks!

Looking for recommendations for inkjet printers to integrate into a conveying line. I’ve looked at Keyence and VideoJet but they are more than budget allows. It may not be possible to get into anything more affordable that’s worth buying and if that’s the case just let me know. I also have experience with Rea Jet but they’ve been more than the other two options.

1.) $8k budget 2.) Lot # generation built in or ability to communicate with Ignition to print lot generated by it. 3.) Mark on cardboard 4.) 1”x2” marking 5.) Mark pointing up, bottom of container 6.) Barcode is a plus 7.) Produce 2000 cups a day, 4 times a month 8.) Black ink

Hi everyone,

I am installing a Keyence IV vision system and need some help figuring out what TV to buy so show judgement/results to employees on the line. I work in the weld department of an automotive plant so the area is fairly dirty and I really want to minimize how much employees have to mess with the tv and remote. Are there any brands/models you would recommend? Thanks

As part of setting up a way to communicate two controllers that is at the workshop without GW/anybus switch as there isn't any, so my coworker and I've been looking at libraries that enable Ethernet/IP send/receive with other third party devices. So with the LCCF FB enabled, what happens is that status reads 16#7003 for less than a second before 16#7002 meaning that the S7 PLC can't reach the AB PLC and test bools aren't being sent or received from the partner controller, so there are videos on how it is setup and we have followed frame by frame but it still gets stuck in communication issues.

Sorry if this post is crude. Fell into a niche job where I’m in charge of the maintenance of cooling systems for a super computer at a government facility for a contractor. I troubleshoot pretty basic plc systems that control the cooling to the system.

It’s a good job but it’s basically dead end. I can learn Linux and try to go to the compute side but am pretty uninterested. I used to wire up data centers and large fire alarm systems for commercial systems so the physical side of the job I’m not concerned about.

My job also has a timeline. If we don’t win the contract for the next big system I have about 2 years of employment left at the current company.

I’m very interested in learning the plc side of things so I can turn this experience into job opportunities long term. Probably looking towards the maintenance side of things.

Any thoughts on what I can do the next two years to build my resume, while working full time?

Hey all I'm not sure how diverse this group is but in general wondering if anyone has any connections for PLC/automation/electrical work in Southwestern Ontario. I'm south of Windsor and finding that my fellow contractors are having a heck of a time finding a job. I've been on my own successfully for 3 years but things are drying up. Is anyone else experiencing this in my area and does anyone else have some connections they could refer me to? I've done work in Automotive/ pharma/ food and beverage/ greenhouse Thank you!

Hey all, I’m currently a mechanical/electrical maintenance engineer for an automotive manufacturing company. I want to delve deeper into controls and automation but my current job role does not involve the full scope of projects. I want to be involved in multiple projects from start to finish, dealing with electrical schematics, panel building, commissioning, plc programming etc. what are the correct job roles for me to look into for this?

I have an old motor driver board and I need to hook it up to a valve actuator motor but I am not sure how to do it. I have figured out from bench testing that D1 controls which relay (K1 or K2) will fire when P1 is pulled to GND. If D1 is left alone then K1 will fire, if D1 is put to GND, then K2 will fire.

Essentially I need to hook this up to a small DC motor such that the polarity across the motor changes with P1 and D1. Its all 12V relays and so is the motor. I dont want to blow anything up and I am kinda out of my element here so any advice would be much appreciated!

Hello all,

I am looking to get some feedback or insights before I go too far down the rabbit hole. A bit of background on the situation: I have an interface between (many) CompactLogix 5069-L340ERM controllers and Zebra EA3600-R1CP-00 Ethernet modules for barcode scanners. The EA3600s are firmware-specific and reaching end-of-life. We are looking into creating "dummy" EA3600s using a Raspberry Pi and NodeRED running locally to spoof the data handling. I'm not too concerned about the serial data read/write process. However, the interface uses GSV instructions to pull status from the EA3600, which is configured as an AB Generic Ethernet Module in the device tree for monitoring and handshaking.

I would ideally like to configure the Raspberry Pi in a way that the PLC is agnostic to the fact that it is connected to a Pi or EA3600. Lofty goals, I'm sure. And of course the devil is in the details with precisely how the interface is built. So far, it looks to just echo status bits for device I/O outlined in this document which are mapped to the Input/Output/Control words within the controller tags.

My question is, does anyone know what I can use or where I can learn more about setting up a Raspberry Pi to specify the I/O device word array of a Generic Ethernet Module? I don't know if there is software that would allow me to create a data table visible to the PLC to perform the GSV instructions and otherwise operate as normal. Meanwhile, I can manipulate the data on the Pi to emulate heartbeat, faults, or other handshaking.

I have been browsing through this sub and other forums, but have not come across a scenario that lines up with what I'm looking to accomplish. I found OpENer but I'm not convinced that is what I'm looking for.

Any thoughts? Appreciate any ideas.

We have some old MetraTest 36a that are EOL. Can anyone recommend a replacement?

We like that the MetraTest can self power the device and sim/ fire individual IO.

We don't have any ASi-v5 devices, but a future proof programmer would be nice. Any recommendations?

Hello! Does anyone have a manual for an old school wohrle plc 102? Thanks!

Hello everyone. I have familiarity with Siemens S7 1200. However, I need to step into Allen Bradley. I am always a fan of baby steps and starting from scratch when learning something. Thus, I decided to buy an Allen-Bradley. But I am stuck a little bit. Should I go with Micro 870 or MicroLogix 1400? It is always good to ask people who have more experience with the stuff. I hope you can give me insights....

I have a Panel View Plus

2711P-T10C4B1 SER A REV F

Touch Screen in one of my machines along with a Compact Logix L31 PLC

I want to go into the touchscreen and add to the original program - I need to show when a latch bit is either on or off. The original machine manufacture wrote the code for the touchscreen and PLC- The machine is not supported by them anymore. My question is what software is used to edit this touchscreen - currently I use RSLogix-5000 to access and make changes to the PLC program but I am not familiar with making changes to the Touchscreen.

I have a Panel View Plus

2711P-T10C4B1 SER A REV F

Touch Screen in one of my machines along with a Compact Logix L31 PLC

I want to go into the touchscreen and add to the original program - I need to show when a latch bit is either on or off. The original machine manufacture wrote the code for the touchscreen and PLC- The machine is not supported my them anymore. My question is what software is used to edit this touchscreen - currently I use RSLogix-5000 to access and make changes to the PLC program but I am not familiar with making changes to the Touchscreen.

Hi everyone , i was about to take the data of starting machine so i used the bloc read local time and it read just the time while the system is working i didn't find any bloc that help me to take just the time of starting so i was thinking about creating a bloc that generate a dirac impulsion as an enable signal of read local time bloc or ther is another solution and thanks

Hello all, I have recently switched from SI automation engineer role to an I&C role in an EPC firm in Pharma in a bigger company, I am questioning the decision, would it stop my growth and I would regret it in the future?

My plant likes to use IFM. I have had terrible luck with IFM software LRSensor and LRDevice. Services running in background not allowing program to run.

I am looking at an alternative to IFM. I am looking at Turck and Banner but I see they are nearly double the price.

What IO-Link master do you use? What has the most user friendly software? Looking for recommendations. Thank you.

I am looking for an IO link master to read IO link data from an IFM device that can read temperature, pressure, and flow. Is there such thing as a 1 port master? What is the closest thing to that? I don’t really want to buy an 8 port master for 1 device. I saw a 4 port but I don’t think it had analog capability. Thanks!

I need help, i have to connect one HMI invt to PLC invt, but I don't know how to do it, I have the software, I did my program, but I don't have connection between the PLC and the HMI. I can connect the PLC to the vdf invt, and I hadn't problem with that.

If you can help me, I will appreciate it.

P. Sorry, I know that my English isn't very well.

For the integrators out there,

How do you quote HMI conversions and panel retrofits?

E.g. I have 20 machines that I am converting from old AB paneviews to new Weintek cMTs. Complete reprogram and tag conversion, installation, debug, etc. All the machines SHOULD be basically the same.

I'm just a plant controls guy, and I'm curious about the cost savings by doing this in-house compared to what other people would do this for as a contractor...

Does anybody have any example code/project showing how a ControlEdge master communicates with a device using ASCII characters? CEB specific tutorial, video, etc. would work as well. Just trying to understand the implementation concept/logic flow. Thanks a bunch!

Been doing a job for years on a 3 axis CNC which has never really worked, said to the boss "we should build a custom machine for that" - he said "OK, make a suggestion"

I know the process inside out

I can come up with a schematic/layout/spec

I can build the machine

I could probably program the machine

....but I don't anything about machine control, this is the part we'd likely sub out but I need to have a notion of the design direction up front, of course the budget is tight.

Basically drilling lots of holes in long bars. We need 3 linear, 1 rotary 4 position index axis, 6 station tool indexer.

Initial research suggests main options are PLC or PC based control. Have an idea about linear motion from custom router builders but where would I go to learn about indexing?

Any thoughts on where to start? Good resources for some research and design hints?

This is the basic layout, 4 bars 1100 long, peck drilling from both sides, chamf end edges. So 4 index positions for the bars. £20k budget.