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Old April 3rd, 2021, 03:42 PM   #16
swedeleaner
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Quote:
Originally Posted by jhenson29 View Post
Just the (vague...) resemblance to electrical schematics, and it’s (maybe?) easier for non-programmers.

I prefer ST. Graphical languages are pretty much universally worse than text languages.

Also...we may have rolled over to 2021 now. I think it happened back around January.
I know why LAD became popular, sure had its place in history.
IL becomes quite nasty with nested OR/AND.

Graphical languages has its drawbacks, but general overview is still better imho.
Calling a PID or calculating attached formula is quite smooth in FDB. You’re welcome to prove me wrong bud..

I were pointing at a decade with the reference to 2020. But please, educate me more about the time we live in.
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Old April 3rd, 2021, 03:54 PM   #17
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Quote:
Originally Posted by I_Automation View Post
Not sure of the correct word, but "chronologically" speaking it is 2020 until 31 December 2029, then it's 2030 for about 10 years
One would use “the 2020s” to refer to the decade...

It most certainly is not 2020 until 12/31/29.
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Old April 3rd, 2021, 03:56 PM   #18
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Originally Posted by drbitboy View Post
Haha very funny, such naivete. Please stop trolling.



I have a saying: "the only things I don't like about C (or Matlab or C# or Java or Javascript or Perl or Python or etc.) are their proponents." Do I really have to add as underpowered, arcane and boring a language as ST to that list?
I usually roll with FBD, keeps both bit logic, math and more advanced functions streamlined. But some functions does work best in ST.

I were schooled in LAD and switched..
But please, tell me when LAD is the best alternative. When some old electrician is suposed to troubleshoot a machine at standstill?
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Old April 3rd, 2021, 03:58 PM   #19
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Quote:
Originally Posted by swedeleaner View Post
I know why LAD became popular, sure had its place in history.
IL becomes quite nasty with nested OR/AND.

Graphical languages has its drawbacks, but general overview is still better imho.
Calling a PID or calculating attached formula is quite smooth in FDB. You’re welcome to prove me wrong bud..

I were pointing at a decade with the reference to 2020. But please, educate me more about the time we live in.
You can’t fit near as much information in graphical languages and complex relationships are messy. I’ll take a text language over graphical anyway.

This next statement is probably subjective, but I also think properly formatted numeric and Boolean expressions are easier to read in ST. Including the one you linked.

“The 2020s” is a decade. 2020 is a year. Feel educated?
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Old April 3rd, 2021, 04:02 PM   #20
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Originally Posted by swedeleaner View Post
I usually roll with FBD, keeps both bit logic, math and more advanced functions streamlined. But some functions does work best in ST.

I were schooled in LAD and switched..
But please, tell me when LAD is the best alternative. When some old electrician is suposed to troubleshoot a machine at standstill?
This is one of the biggest problems with control systems...people wanting to use the source code to troubleshoot. If you have to look at the source code to troubleshoot the machine, it was architected wrong. The program is for debugging. The HMI is for troubleshooting.

LAD is better for people who know only know LAD. Period. But FBD isn’t any better.

ST isn’t great either, but it’s the least worst choice.
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Old April 3rd, 2021, 04:17 PM   #21
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At the risk of perpetuating the hijack of the OP's thread.

I've never understood the animosity that fans of the other IEC61131 languages seem to have towards ladder logic. Sometimes they seem to be on a mission to eliminate it. For as long as there have been PLCs there have been people predicting the imminent demise of RLL. And yet, some 40-odd years on, it's still thriving.
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Old April 3rd, 2021, 04:27 PM   #22
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Well, I had my fun.
Seems like the LAD-thingy is still quite sensitive, I guess I’ll leave it at that.
Mr Henson, had some fun reading your posts.

But you should work on your scorched earth tactics..
You don’t even like any of the IEC-languages, what are you doing here?
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Old April 3rd, 2021, 04:30 PM   #23
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Quote:
Originally Posted by swedeleaner View Post
But please, tell me when LAD is the best alternative. When some old electrician is suposed to troubleshoot a machine at standstill?

The same as when ST is the best alternative: when it is. Every application is unique, the language is irrelevant and makes no difference to the desired behavior. Example from another domain: I was working on a project that built a web interface to control near-realtime operations of a mission; of course Javascript was part of the client- (browser-)side code; but they also use JS (instead of Python or Ruby or whatever) for the server side code; the result was that every coder hired could understand and contribute to both sides of the project. Another example: I was at a talk during a conference, and some C (or other language) fanboy asked a silly question: why did the speaker's team use Fortran? The answer was three words: because we're engineers.



And it is not just old, but any, sharp electricians, who can look over my shoulder and spot my mistakes, and at least start debugging if not solve the problem while I am driving in at 3AM (for problems that go beyond what the HMI offers). That is no small advantage. Of course many will be lost when I use a constrained Chebyshev polynomial to approximate cosine on a MicroLogix, but that is equally true of ST and FBD as well.


Programming language snobbery is pointless.
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Old April 3rd, 2021, 05:08 PM   #24
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Quote:
Originally Posted by swedeleaner View Post
You don’t even like any of the IEC-languages, what are you doing here?
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Old April 3rd, 2021, 05:28 PM   #25
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So is the consensus then, we are not going to answer the question, because we are 95% confident it is homework, and not just a fun puzzle for drbitboy et.al. to solve?

Because I kinda feel that Sequential Function Chart is the greatest of the IEC 61131-3 languages, even though I never use him all by himself.

And gosh darn it if I ain't gonna party like it's 1999 when 2022 is finally upon us, regardless of whether it is the 2020s, 2020 (which I pronounce as "the 20s" because there's two of them), but hopefully not still COVID-19.
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Old April 3rd, 2021, 05:38 PM   #26
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Originally Posted by AustralIan View Post
So is the consensus then, we are not going to answer the question, because we are 95% confident it is homework, and not just a fun puzzle for drbitboy et.al. to solve?
I answered the “challenge” within the posted constraints. I’m not sure what the issue is.
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Old April 3rd, 2021, 07:05 PM   #27
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Originally Posted by jhenson29 View Post
This is one of the biggest problems with control systems...people wanting to use the source code to troubleshoot. If you have to look at the source code to troubleshoot the machine, it was architected wrong. The program is for debugging. The HMI is for troubleshooting.

LAD is better for people who know only know LAD. Period. But FBD isn’t any better.

ST isn’t great either, but it’s the least worst choice.

Almost every single machine I had to troubleshoot or upgrade was designed and built by morons. Some of the largest manufacturers in the western world(Dutch ???). If I couldn't look at the code I walked away; there was nothing to work with.


Even the most basic guidelines for HMI design are always ignored.


There's something seriously wrong out there that such substandard machines is allowed to be sold on the market. Substandard in design, functionality and safety.
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Old April 3rd, 2021, 08:05 PM   #28
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Quote:
Almost every single machine I had to troubleshoot or upgrade was designed and built by morons.
All the world is crazy except for me and thee, and lately I'm not so sure about thee.

Several times I've had to do upgrades on machines that I originally programmed. My first reaction upon revisiting my code has invariably been, "what was I thinking???"
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Old April 3rd, 2021, 09:50 PM   #29
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All the world is crazy except for me and thee, and lately I'm not so sure about thee.

Several times I've had to do upgrades on machines that I originally programmed. My first reaction upon revisiting my code has invariably been, "what was I thinking???"
I'm glad I'm not the only one who has these moments of mild embarrassment at the work that former, younger, better looking but more stupid me did.

I had the opportunity recently to do some minor mods on a small water plant I did the code for about 7 years ago when i first started using Schneider M340 PLCs with FBD logic in Unity Pro. My first thought after looking at some of my old code was "... Amateur."

I like to think that it's a sign that I've grown and matured my skills since then.
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Old April 3rd, 2021, 10:36 PM   #30
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I am not sure we:re talking about the same level of poor design, mechanical and control.
The main point though is that having access to the inner workings of the system is often vital to troubleshooting. Many systems we use daily offer tech support as an alternative to looking at code; because the users are not required to be control experts or electronics engineers. That applies to most electronics we use today.

Some manufacturers deliberately provide little in terms of troubleshooting "tools" to motivate the customer to purchase and pretty much rely on remote tech support and having to purchase replacement control components from them.
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