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Questions tagged [ladder-logic]

Ladder Logic is a programming language that model a program using graphical representation of circuit diagrams of relay logic hardware. Please include in your question which model and manufacturer of the PLC, as the resources in the system are heavily dependent on the hardware.

26 questions
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Testing ladder logic

We all know the various ways of testing OO systems. However, it looks like I'll be going to do a project where I'll be dealing with PLC ladder logic (don't ask :/), and I was wondering if there's a good way of testing the validity of the system. The…
Erik van Brakel
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Best IDE for PLC ladder programming

Recently I trying to learn Ladder Logic programming for PLCs, but I want to know if there is any IDE to create Ladder programs better that Step7 or cx-programmer? Is there any plugin for Visual Studio or Netbeans that I can use? Finally, is it…
Ali Foroughi
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PLC ladder logic sequence

I've spent hours and a trees worth of paper sketching and I haven't been able to stumble upon anything to get me past this problem. I'm able to switch back and forth between two motors but I can't figure out how to turn the motors off while…
internRob
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Exporting Ladder Logic in Tia 14

TL;DR: What is the best way to Export Ladder Logic in Tia 14? Recently my company has started using Tia Portal v14. The update was due and we have begun to do some work with the S7 1500 series of CPUs. It has come to the attention of those in my…
JustinCoplin
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4 answers

How to prevent division by zero in ladder (PLC)?

I have to make a circuit to prevent dividing a number by zero. I tried to put a condition in front of the division block but it did not work. What could I do to solve that? Bellow is the non-functioning circuit that I tried. I am using the RSLogix…
Vinícius A. L. Souza
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1 answer

Reading PLC register using ModBusTCPCom in .Net results in address not found

I have to update an old WinForms application. The application uses the AdvancedHMI .NET software. I am connecting to the PLC (AutomationDirect DirectLogic 06 Series) with no issues, and various other registers are being read accurately. I am…
Joe K
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How to convert an array of characters into a string in Studio 5000 Logix Designer ladder logic

I have a barcode scanner that communicates with a 1756-L75 ControlLogix PLC over RS232. The data from the scanner is read in byte by byte and stored in a SINT array as characters. It includes a header and the barcode data. The barcode data is…
lcecl
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How do I set an unlimited timer in ladder logic?

I am a newbie at ladder logic. The program linked below runs a timer, and updates the delta time between each "frame". https://www.plcfiddle.com/fiddles/e56c6cf0-d858-4327-b291-7cdc1067ffc1 The preset value for the timer is set to 10, so the timer…
Evorlor
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What data structure can I use to save nodes from a PLC ladder diagram in python? (Multilevel linked list with loops?)

I've been looking around but cant seen to find what data structure I can implement to represent a ladder diagram from a PLC program PLC in python. For those not familiar with ladder diagrams. It is basically a multilevel linked list where nodes in a…
Carl Hidestål
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1 answer

How can I time taken between 2 events

I am trying to record the time taken between 2 sensors being activated I am using ladder logic for my university project although struggling with code to record time taken between two events so as to store the information
Gary Mcdevitt
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How to enter string value into Delta PLC?

I would like to insert string value into PLC, I searched a lot of information but unable to get an accurate method to do it. The plc that I using is DVP-14SS2 and I using wplsoft as the software to edit ladder diagram. Someone can guide me on how to…
Jason Lee
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How to create a blinking light with a push button in PLC?

I have create a ladder diagram to control the light with a push button. I want make a blinking light with my push button. I have create a ladder diagram to control them. When I press the button, the light will start to blink. However, when I release…
Jason Lee
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Setting single bit Siemens ladder

I have a value stored in MW20 and I need to set to most significant bit to 0 without using bit operations but I don't find how I need to do this. I know this: ----> MB20 = D7 / MW20 = D7C5 \ ----> MB21 = C5 So I need to set the…
Seppe Mariën
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Ranking of a user in mysql

I know this has been asked and solved in the past but I couldn't exactly apply the already solved problems to mine. What I am trying to do: Get the global ranking of a user along with the 10 below and 10 above them and the top rankings for the top…
nonerth
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how to make my ladder plc hidden ?I want to make it secret from other people?

if I want to create a ladder diagram on step7.after I want to make it secret from other people?
tarik blal
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