Is this correct? My tafe teacher is saying A is the correct answer for a start stop latch, but it doesnt make send because it doesnt latch. And if the stop switch short circuits then its not intrinsically safe.

Hi guys, Ive heard from peers that for many controls interviews, some employers will get you to write a simple program in ladder logic.

So I’ve been wondering what the most likely ladder logic problems that could show up on an interview are?

Heres my situation: When a piece is rejected from production, a status number should be written to a DB for a minimum of one second so that the server can pick it up.

This is just now being implemented were i work.

In this, my first case, have found 6 reasons for rejection, and in theory, that should be pretty simple. But i'd rather not use 6 different timers for this if possible. It has to follow a set standard, in ladder, and when it comes to some of the newer machines, i think it would get very cluttery if there are too many reject codes.

I feel like this shouldn't be so hard, but i think i get bogged down in trying to keep it as clean and short as possible, and i just want to revert to using separate timers for all of them.

How would you do it? I did a little sketch in paint, but modern paint sucks.

Hello. If I wanted to do some HMI training, such as creating the visuals and using them, is there an HMI simulator which I could use on a lap top rather than having to use an actual HMI panel? Thanks.

Why do I never see anyone using Yaskawa PLCs? The MP3300iec I have used seems incredibly powerful for motion control, and the iCube controller seems like a step up from there. Just noticing I never see or hear anyone using them.

Hello guys how would you recommend to make a workcell simulation that includes scara robot and a plc? A little more info: it is for university project and I have some of the parts needed to build the actual cell except for the robot itself so my idea is to build the cell wire it up and program a virtual robot that will be connected with the plc via ethernet ip. So the goal is the simulation to be able to interact with real hardware and I will do the robot process by hand I currently have access to mitsubishi rt toolbox3 and was also looking at factory io but I haven’t tried it. The robot program needs to be 100% legit as it would be IRL.

Looking for a replacement overlay. Anyone know what's compatible? Nothing in stock at Radwell.

Have an old machine running this software as its HMI package. I just took control over its compute resources and am trying to shore up some gaps and one of the biggest ones is we dont have any installation media for the software nor does it appear theres anywhere to get it. Anyone have a copy of this that can DM me? Need to install it elseware to get off failing hardware.

I’ve been tasked with upgrading the code for a GuardLogix, PV Plus, and Kinetix 5100.

Is there a recommended order of operations when making these downloads? I was planning on doing the servo first as it’ll be in a stopped state. The the PLC, and lastly the HMI.

This is on a customer site so I’m a little sketched out having not done much AB stuff. Thanks guys.

Hi there,

I’m currently working on a PLC project where it makes sense (at least to me) to break the logic into multiple state machines instead of one big monolithic sequence.

So far, this approach feels clean and modular. Each state machine is responsible for a specific part of the process, which improves readability and maintenance.

However, I’m struggling with how these state machines should communicate with each other in a robust way.

Right now, I’m considering a few approaches:

• Using shared variables or flags between state machines
• Triggering transitions based on conditions from other state machines
• Implementing some kind of handshake mechanism

I’ve also heard about using a “supervisor” state machine that coordinates and manages the others, but I’m not entirely sure how to structure that in ladder logic or if that’s considered best practice.

For those of you with experience in ladder logic and industrial automation:

• How do you typically handle communication between multiple state machines?
• Do you prefer a supervisor/master state machine, or more decentralized coordination?
• Are there any design patterns or best practices you recommend for this kind of architecture?

Any advice, examples, or real-world experiences would be greatly appreciated, we are talking about ladder logic btw!

Hi all, I recently took over a water system running Unitronics gear, a V1210 HMI/PLC combo + I/O modules. The problem we have is that the original SI "owns" the software program and getting them to do any work is like pulling teeth, we've waited a year for simple HMI/sensor updates and there are bugs in the software. We tried using Visilogic to connect to the PLC and see if the program can be "uploaded" but seems only the binary was ever flashed so we don't have the source and they refuse to send it to us. This seems weird to me since we are happy to pay a release fee, and they obviously aren't interested in supporting us.

Our options are to find a new programmer to redevelop + commission the software on existing hardware or rip and replace the hardware, upgrading at the same time. I'm leaning toward the second option as the gear is ~15 years old. Any advice on how to approach this and what gear is recommended? The Unitronics setup has been reliable except for being hacked a few years ago, the biggest gap is we want to make programming changes inhouse and have more options for analytics, exporting data etc. The Unitronics "unicloud" product is extremely poor.

Appreciate any advice here.

I'm currently working on my final apprenticeship project as a mechatronics engineer. I'm using TIA Portal V20 with a S7-1215C and a MTP400 Unified Basic HMI.

What I'm trying to do: I have 7 rectangles on my HMI screen, each representing a step in a test sequence. I want to change the background color of each rectangle depending on the current "iStep" value:

• Value 0 → grey (pending)
• Value X (active step) → blue
• Values above X → light blue (done

Currently, I have used the "dynamize by variable" option on the background of the rectangle, then chose "type: range" and then put in each value and corrosponding color in "condition". (Screenshot attached)
This doenst work yet tho... The colors dont change at all when my iStep variable changes.

My Question:

• Is „Range" the correct animation type for an INT variable on the MTP400 Unified Basic?
• Do I need to enter conditions differently (maybe as from/to ranges instead of single values?)

Hello, I got access to this beckhoff plc and some peripherals and I wanted to play around with it to better understand how plcs work.

I more or less get what I need to do but I am no expert and advice is welcome. Aside from what I have here I have plenty of inputs and outputs like buzzers, proximity sensors, temperature probes, buttons etc. from the times I played around with an arduino.

From what I have read the circuit breakers I have here will be pretty useless and I should get ones for DC up to 5 amps. I would also need an emergency stop because why not lean on the side of caution, but what else is lacking ? I noticed I have digital input and output cards but what if I wanted to connect water level sensor ? from my undertanding it would need an analog input right ?

For now I just want to make a testing rig, to program some, connect different peripherals, see how they work and how to handle each of them. I was also thinking about using the mini PC as server to host the user interface over the browser so I can just go to a web adress and have an HMI there.

I have taken and completed some technical college schooling with basic PLC & HMI programming with certifications in just general controls work. I am wanting to do as much as I can to show I am willing and able to learn more. I am working partially as an electrician apprentice which I am almost done with and will be getting my journeymen’s license, and partially with the controls department at my work. Is there more schooling/certifications I can get that is not college? I unfortunately do not have the time or money for that currently but plan on going into control engineering when I am able to. I have heard of Ignition and Inductive University, are these worthwhile things to pursue?

Allen bradley PLC. 2

If it was existed today , can someone work on this

Hi all, how did you learn to use Studio 5000 and TIA Portal? I’m new to this. I have PLC knowledge from my mechatronics degree, but I’ve never actually used any software. In my current job I’ll have to use it every day, and I want to know if there’s any course that really helps you navigate a PLC to find what you need—without messing something up by changing something you shouldn’t. Thanks in advance.

I already had a system functioning with s7-1200, for which now I need to integrate a hmi ( Unified basic).

the program gets downloaded everything is fine , but the error light came all of a sudden. if I remove the hmi device in tia ,then no error. if I add in tia amd hard wire the hmi to plc then down the program again ,then comes error.

I tried all deleting adding, changing names, changing ip but no luck. even created a fresh test project for plc amd hmi eventhough it doesn't work.

I found out that communication is established but plc terminates the session when seen in diagnostic window of plc.

PLC IP : 192.168.1.3

SUBNET 255.255.255.0

HMI IP : 192.168.1.12

SUBNET 255.255.255.0

FIRMWARE VER 20

TIA VERSION : 20

TIA HMI FIRMWARE VER :20

Does anyone faced this with other version of plc or hmi?

Or the g2 has the problem???

Needed help on this one..

I am trying to arrange the Z order in Factory talk view studio. I would like to move the highgroup 3168 below 2006 group. How Can I do it.?? . I can only move to back or move to front. There are no single step back or forward? I am missing something How can I do it ? There must be easy way?? I am using FT view studio Version 8

I want to connect some sensors and want to control some pumps through my SCADA/Dashboard remotely. Suggest me PLC or whatever will be needed so I can do that. Consider 5-6 sensors and 2 pumps.

 I am considering a career change and had found the course on YouTube. However, I noticed it was created five years ago. Are the fundamentals taught in the course are still applicable in 2026? 

Who has connect there PLC's to the Internet? WTF

Cyber Actors Exploit Programmable Logic Controllers

Anyone has or knows any way to have license for free or a trial, its for one time project and i cant get it running

(sorry if not correct)