Create ladder diagrams in Labview

[LawsJespersen]

Hi All

I am pretty new at lab view, I’ve done a few programming’s together with a DAQ.

My job(student) is now to simulate a process line. The processline includes the handling of a product from process to process and together with solid works simulate the processes. Because we do not have the tools and machines, we only want to simulate the processline. And because of that we have decided to use Lab view instead of cx-programmer, because we then can have lab view working together with solid works as a simulation.

My problem is I am not familiar with creating ladder diagrams in lab view. I've bin searching the subject but did not find anything useful. Any of you who can help or have any guides ?

Sincerely Laws Jespersen

Student at Aalborg University 

[Ben]

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@LawsJespersen wrote:

Hi All

I am pretty new at lab view, I’ve done a few programming’s together with a DAQ.

My job(student) is now to simulate a process line. The processline includes the handling of a product from process to process and together with solid works simulate the processes. Because we do not have the tools and machines, we only want to simulate the processline. And because of that we have decided to use Lab view instead of cx-programmer, because we then can have lab view working together with solid works as a simulation.

My problem is I am not familiar with creating ladder diagrams in lab view. I've bin searching the subject but did not find anything useful. Any of you who can help or have any guides ?

Sincerely Laws Jespersen

Student at Aalborg University 

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I have been coding in LV since the last millenium and the absolute worse nightmare applications that arrived at my desk were developed by Ladder logic programmers!

Let me repeat THE WORST!

Speaking for the ones I have had to re-write, the developers start to look at LV diagrams as if they are ladder logic on its side.

The approach to writting lader-logic and LV are different.

So the more sueful thing I can tell you is do NOT try to write ladder logic in LV! (Please please please please! )

Search this site for the term "State Diagram" and spend some time trying to understand how to think in terms of "states".

You can ignore if you want. That is fine. I have done my good dead for today.

Ben

[Ben]

Another warning I would have loved to pass to the developers of the code I have seen.

Also note that locals and property nodes are not intended ofr data storage. They should be looke at as if they are I/O devices and only touched when you have to touch them.

Learn about Shift Registers.

War story

In the lsst )pianful) three weeks I have been updating an app that suffered from Ladder-logic thinking. The CLA (cetified LabVIEW Architect) I was working with could barely make sense of what was going on in the code. It took me three days of re-wiring and creating sub-VI to get it down from twelve screen wide sequence structure into something that resembles a State Machine that is not managable.

SO please don't try LL in LV.

Ben

PS Do I sound despearte?

[PJS]

Don't hold back Ben, tell us how your really feel!

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@Ben wrote:

Another warning I would have loved to pass to the developers of the code I have seen.

Also note that locals and property nodes are not intended ofr data storage. They should be looke at as if they are I/O devices and only touched when you have to touch them.

Learn about Shift Registers.

War story

In the lsst )pianful) three weeks I have been updating an app that suffered from Ladder-logic thinking. The CLA (cetified LabVIEW Architect) I was working with could barely make sense of what was going on in the code. It took me three days of re-wiring and creating sub-VI to get it down from twelve screen wide sequence structure into something that resembles a State Machine that is not managable.

SO please don't try LL in LV.

Ben

PS Do I sound despearte?

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[DaHelmut]

Hi,

In addition of what Ben said, you can have a look at the Statechart Module , but it requires a good knowledge of LabVIEW programming and may not be easy to use if you are a beginner.

Regards,

[tbob]

Having done ladder logic programming myself, I agree with Ben 1000%.  That language was intended for non-programmer types to create a program.  The concept of throwing switches could be grasped by almost anyone.  The rungs of a ladder are pretty straight forward.  This made it fairly easy for a tech-type to create programs for PLCs.  But Labview is a REAL programming language.  My advice is to take advantage of the full power or Labview and forget ladder logic.

[carlosxyz]

Wow this post is awesome, i am writing a proyect to present my degree in automation with a PLC siemens, I am simulating the proyect with simulation loop from Control Design & simulation tool kit, I want to create a DSC to monitor all the variables, and this post made me think :S 

I know that Ladder logic was created to the technicians for Ford, "a few" years ago, do you think that ladder logic will dissapear in the future ?

thanks.

[johnsold]

I think ladder logic will disappear about the same time that anti-gravity platforms cause ladders to disappear.

Lynn

[tbob]

I disagree with Lynn.  I think ladder logic will still be around even after anti gravity platforms replace ladders.    There are just too many PLCs out there that still use ladder logic.

[josborne]

>>But Labview is a REAL programming language. 

But I thought LabVIEW was just a proprietary, application-specific development environment? 

Heh heh ... lets not go down that road again.