Programming standards

[codedRed]

I'm a new programmer that was promoted from a technician. I want to have a set of rules to follow so that my programming is generally setup the same and so that there will be no complaints of sloppiness in the future by co-workers. Does anyone have a recommendation? All of our PLCs are Rockwell if that helps.

 

[widelto]

I have visited this pages and they are a good place to start:

https://www.youtube.com/results?search_query=rslogix+5000+programming+tutorial+

 

[geniusintraining]

so that there will be no complaints of sloppiness in the future by co-workers...

The only way this is possible is if you work for yourself and by yourself, then you must also password protect the program so your customer will never see it.... and if your wife walks up behind you make sure you shut off the screen so she can not see it either

Then and only then... no one will complain, other than yourself

 

[dogleg43]

It seems like the obvious place to start is by asking your boss this question.

If your facility doesn’t have any standards then you’ll have to start by deciding whether to use pure relay logic, STL, statement list, etc.

Good luck.

 

[kalabdel]

I'm a new programmer that was promoted from a technician. I want to have a set of rules to follow so that my programming is generally setup the same and so that there will be no complaints of sloppiness in the future by co-workers. Does anyone have a recommendation? All of our PLCs are Rockwell if that helps.

Here are a couple Siemens guidelines; Programming Guidelines and Programming Style Guide.


And this link is for PLCopen guidelines. Most relevant to your question is their "PLCopen Coding Guidleines" which is right at the top of this page. When you click on the link you will get a page to enter some information and a "Submit" button, you will still be routed to the document if you do not fill out the information and click submit.


And there's IEC61131-3 which I understand those guidelines are based on, and ISA101 for HMI development.
These should keep you busy for a while.

 

[BITS N BYTES]

Attached is link to great resource for organizing programming standards and techniques.

Have followed this approach for years with good success.
http://www.contactandcoil.com/patterns-of-ladder-logic-programming/

 

[Jim3846]

This is an open ended question: Standards can cover, common spare parts, follow NEC but what is plant standards? as it relates to any install at your facility, plc manufacturer standard, PLC programming software standard and revision level, plc coding standards, etc....

See standards cover a bigger range of questions then just programming. Stirring the pot.

 

[diat150]

The stuff you really hated as a tech and caused you trouble... dont do it.

 

[Engineerj22]

Is there a way to get a hold of the ISA101 standards without having to pay 180 USD for the damn thing?

I might also be missing something.

Thanks,

 

[Nova5]

Find out your organizations programming standard. This is hit or miss. One place I had did have a "standard" but it was for a naming nomenclature. The best standard is to K.I.S.S.

One can right intentionally convoluted code.. don't do that. Other programmers who have to debug your **** will hate you for it. Then probably recode it to simpler.

 

[geniusintraining]

One thing that may help... find a style that you like and copy it, if you have seen one that you like and can understand do what they are doing. I have done this a lot when I first started with AutoCAD, did the same thing with my first 5000 program maybe version 8ish but the engineer did a great job and I liked the way he structured the program so I did the same and steal shamelessly

 

[drbitboy]

good writers borrow; great writers steal.

 

[I_Automation]

Then and only then... no one will complain, other than yourself

I sometimes open programs from builds years ago when I was younger and wonder WHAT THE H*** WAS I DOING


Safety demands change, new methods are developed as you write more programs, and you mature.



I tried setting some standards as you want and they eventually turned out useless or worse, inappropriate or counterproductive.

 

[Jim3846]

I remember some standards i liked was where you had a file that held all the outputs. And then the outputs followed from local rack to all the remote racks. If you tried to order them by flow around system it would turn into a mess. But all the functions resided in its area or local program. Then those functions had its ouput bits that mapped into the output file.

Inputs - this kind of evolved where i see people have buffered IO in a file. Used aliasing of all inputs. Usually i thought if you alias an input to put it in the controller tags. I have seen where people alias a tag in a local tags, which really confuses people.
I think a lot of programmers have gone away from buffering IO inputs to just using aliasing in the controller tags.
You could also just have a mapped IO for the inputs if you had a standard machine, maybe the IO was different for different machines.

 

[dogleg43]

To the OP:
Google “5-rung programming”. Although this is now considered old school, it is a perfectly acceptable way of programming a machine that is a sequential operation.

The OP didn’t say if he’s doing process control, machine control, or what. If we knew, it might narrow things down a little.