Dangerous novices programming plc's

[dahnuguy]

Reading through this thread I think I'm in agreement with the majority of posters in saying that if 'experience' and 'competency' were a pre-requisite for doing any work then how would newbies develop.

Newbies should develop under a qualified veteran, after qualified instruction, for a number of years. Yes I see the variables, these are not for me to decide and I am not debating how long training should be only that there should be some. As of now , none is required.

Training only goes so far.

but so far is better than none.

To develop properly you need to be in the 'thick' of it actually making changes, modifying code, coming across and then surmounting obstacles. This is how we as programmers, and as humans, develop and improve.

and if no one is in any danger , I agree with this hands on cavelier aproach. Jump in and get wet. Then discover if you can swim. I have been thrown to the wolves on many occasions, I enjoy the rush.

I think anyone who has been in PLC's for a while will have had that experience of being a bit 'out of their depth' but you work through it and learn from it.

and if you get lucky the first couple of times and no one gets hurt then you gain the confidence to go to bigger things. Maye that's good , sometimes it's not.

The problem with 'licensing' would be that as soon as it was introduced it would become a requirement in order to comply with health and safety laws. This would mean that only the people who had attended the course would be in the programming roles.

I've been around long enough to know that just because you've done the course doesn't mean you can do the job!

yep qualified and certified does not mean good

no training and little experience can't be better.

I think it should be down to individuals to be able to ask for help if they need it or even get someone to check their code if they are unsure of anything.

yeah, my english teacher used this logic on me "Why don't you look up the words you missplled?"

and I said "Why would I look it up in the dictionary if I think that's how it's spelled?!!!! Do YOU look up words you think you spelled correctly???????"

Do you ask someone to check your code if you tested it and it passes your testing and logic checks? What about through lack of knowledge or experience you miss something? and then something bad happens? I have noticed that when someone gets hurt the investigator is usually some guy that has no idea what's going on and gets snowed by the company into blaming the operator and never is the machine or the code ever questioned. And what if I could prove it was a machine defect that caused the injury / death? Who is responsible? The company? the boss? the programmer?

nope.

and that's why we have no certification/ education requirement.

You can't run a daycare without a license and training and inspections. But a 16 year old girl is frequently trusted with all the kids and the house for hours.

I have seen so many shortcuts in every part of manufacturing, and so many good people who were slowly "taught" to accept it due to lack of training.

Someone mentioned Air Force iinstruction.

The USAF will train you on a task until you can not screw it up through lack of knowledge or training and they document every step and have you and the trainer sign off on every task, so when you do screw up, you can be held responsible. You know the job inside and out BEFORE you are let go on your own. Maybe this system is why I feel so untrained as a civilian. Nobody signed off on my PLC training and I dont know what I don't know.

And, to reiterate what has been said many times in the post, machine safety should never be reliant on the PLC anyway.

:site:

No it shouldn't but it many machines it so is. If machine safety was not affected by the PLC I would only have a quality arguement and would drop the whole debate.
I have been drilling safety into every manager I have ever talked to, most don't want to hear it.

Job one is production............safety is rarely in the top 5. I think it should at least make the top 3.

 

[dahnuguy]

Secondly, seeing the name dahnuguy, what happened there?? he suddenly appeared and was all over the board like a rash, making long posts which led me to believe he was going to be the new 'Terry Woods', then zap.. vanish..

It strikes me as odd that anyone noticed I went missing.

Most places where I speak frankly, I am not missed when I leave for a bit.

 

[ziggys]

thanx for your input, I worked for a company that designed and built custom automated plc. machines, I've seen it happen with experienced programmers!

 

[brucewoodrem]

pls help with dl105 drum sequencer ladder layout

I have read chapter 6 over and over of the manuel but still cant get an understanding of how to write the ladder to start a drum sequencer

 

[ziggys]

crash

If I was a programmer I would give you the answer, i bought the dvd's and books, phil melore tells me to practice, how do you practice when you don't know where to start! i think a machine crashes when safety's aren't built into the program!

 

[Bitmore]

I would think those individuals entrusted with such,and had limited knowledge, would seek out advice or strive to learn. I think/hope all of us try to test our logic in a condition that does not endanger people.
I have ALWAYS breadboarded or simulated my logic before implementation. Even after trying my logic on the simulator or breadboard I would ALWAYS insist on testing equipment in real time without risking life or limb.

 

[rustysmith52]

There has been quite a bit of excellant information posted here on this topic. Not so much on programming help, but consequinces of poor programming. I'm an instrument tech. with a very limited knowledge of plc's. I have assorted switches and relays and a temperature controller with an on/off output controlling my hot tub. I also have a surplus mitsubishi fxon 24 es plc which I plan on integrating into my system. With the help of folks on this site and others, I'm slowly developing a workable program. My point, which goes along with what a lot of you have talked about, is that this plc is sitting on my workbench with switches for inputs and lights for outputs. It won't go anywhere near my hot tub until I've checked and rechecked every scenario of what could happen. I have to be very careful combining water, electricity, kids and quite possible, a few drunk adults. I'm glad I read this post and all the replies, it reminded me of how dilligent I need to be to keep this safe. If I feel uncomfortable any at all, I'll probably just buy a new spa pack, but I enjoy projects like this and I'll make it work whether I use it or not.
Thanks for listening.

Rusty

 

[arunsinha]

PLC Training

Quite a discussion Goody has started... I'm not sure if has been touched on in all the replys (I read a few only), but I think there is a larger issue of Automation & Controls education in America that needs to be addressed. For that matter, Engineering as a whole. I've been feeling this way for the past several years, and I see it finally popping up amongst "pundits" and business leaders. Basically, there seems to be a shortage of Engineering Graduates in the U.S., and the problem is much more magnified in our field/subset. PLC programming is not part of many Engineering carriculms(This is not so much the case in other countries, like India). In the U.S., most PLC programming is learned on the job, from manufacturers classes, and perhaps in some trade schools. Many of the "boomers" that are now retiring came up on relay panels, so in regard to ladder logic in particular, it was an easy transition for them. They are now retiring. Kids coming out of school know higher level languages like C, C++, VB (it was FORTRAN for me, back in 1990!)...and like one post I read (about the CE who gave the task back after a month)...these languages don't really prepare you for controls programming.

Answer/solution - Automation & Controls programming as part of Engineering school carriculum.

How to make this happen - I have no idea!

 

[Goody]

I have re-read all the posts and nothing has changed my mind.

It's not education that is the problem, it's the attitude.

Some of the people that are trying to program PLC's believe they don't need training - or at the very least lots of practice on a plc training setup.

Just read a lot of the posts that come in daily on here.

even today some guy is wanting to automate a 300 ton press and it is obvious from his posts he hasnt a clue - and that is why it isnt a joke or a grumble - these guys are out there doing these things.

 

[up_onus]

Hmmm,
Goody. I suppose you never were a novice, and when you were you probably looked right where you were supposed too, because PLCs were simple, didnt have 50 page manuals.
And I suppose you never made mistakes or asked stupid questions to your "senior" engineers.
This is a ridiculous rant.
You sound just like a begining engineer who refuses to look for the answer to your proposed problem and you just come to this site to "say how long youve been here".
Good luck with your whining.

 

[504bloke]

Hmmm,
Goody. I suppose you never were a novice, and when you were you probably looked right where you were supposed too, because PLCs were simple, didnt have 50 page manuals.
And I suppose you never made mistakes or asked stupid questions to your "senior" engineers.
This is a ridiculous rant.
You sound just like a begining engineer who refuses to look for the answer to your proposed problem and you just come to this site to "say how long youve been here".
Good luck with your whining.

We were all novices at one point, i for one dont remember being lazy and googling "How do i program a 300 Tonne press" or even attempting to without the relevant knowledge.

Machines can be dangerous and some of the posters here as goody points out HAVE NO CLUE and shouldnt be dabbling with seriously dangerous bits of equipment, its one thing to program a set of traffic lights but quite another to desing a control and safety system for a press, rubber mill, spray booth etc

When i started with a Square D Symax PLC this had a Massive manual (More than 50 pages) and that was years ago, S7's, Omron, Mitsi and AB's are In My Opinion simpler than the older plc's were and far more powerful. We didnt have ASi years ago or PROFISafe or Safety PLCS.

Anyway thats my 2 penneth

 

[dahnuguy]

The point is over there>>>>>>>>>> you missed it.

Hmmm,
Goody. I suppose you never were a novice, and when you were you probably looked right where you were supposed too, because PLCs were simple, didnt have 50 page manuals.
And I suppose you never made mistakes or asked stupid questions to your "senior" engineers.
This is a ridiculous rant.
You sound just like a begining engineer who refuses to look for the answer to your proposed problem and you just come to this site to "say how long youve been here".
Good luck with your whining.

This is a perfect example of the point being missed entirely.

WE WERE ALL BEGINNERS AT SOME POINT YESSSSSSSS>

AND WEEEEEEE KNEW WHAT THAT MEANT. AND THAT IS WHERE WEEEEEEE HAVE AN ISSUE NOW.

When I was a beginner no one would dare ask me to build a PLC control for a dangerous machine with no help. And if they did ask I was quick to say it was over my head.

It seems this is not done these days.

"Can you program a PLC to make that press run?"

"Sure no problem, I'll look it up online tonight and start in the morning."

"Ever program a press before?"

"Nope"

"Ever program anything before?"

"I did real good in school with the sample problems."

"Ever use this type of PLC before?"

"Nope, I'll figure it out."

"Ever worked with safety of workers in an industrial environment?"

"Nope, but we talked about it one day in class."

"OH ok , sounds good, have at it."

This is what it looks like out here these days.

I pick up new PLCs but I tell the bodss there will be a time delay while I do it. And I still apply all the safety and logic I have learned in the time I have used the other types.

I don't see an issue with some one coming here asking for help learning. Or some one who has worked in indusrial situations and used other brands but has a question about a new brand.

Like I have used brand X for 5 years, but I have no clue about data types in S7.

Or I have used brand X for years, but I just hit a new process and I need some ideas, etc.

But when you want to figure it out for the first time and your intent is to expose operators to your learning curve with dangerous moving parts or chemicals, I have an issue.

I understand I am wrong to ask anyone to be responsible or show restraint.

I understand I am wrong to ask for any accountability.

I understand I am wrong to have such high expectations.

I know, I get it.

Just do what ever and apologize later.

I am amazed at the luck that stops so many people from getting killed in factories every day.

Why push it?

 

[deemz]

I believe there should be some sort of mandatory certificate required to program machines/processes, above and beyond just having a degree/diploma, where you learn about fail-safe design, designing safety systems and have to show and prove that you understand standards like IEC 61508 through a project.

It's more than just programming.

I mean, you should need a license to do this work.

 

[Paul B]

Stand on the plant floor and go through every aspect of the machine - always asking yourself if the end result is the right result. Its a judgement call for many many things.

That's why we make the big bucks is a great catch line - We also have job security.
Experience has no substitute.

Great thread!

 

[PLC_Idiot]

I have been involved with electrical controls since 1976. Before PLC's there were relays. Alot of people who taught me were really good at the relay thing. Most of the things done in PLCs are relay logic. So for many of us, when the PLC first came out it was really more of a transfer of media, instead of mounting relays, we programmed them in. I installed my first PLC in 1982. I was new, and nobody there to teach me. But I understood logic. Does that make me dangerous? Hardly! I have taught many to make transition from hard ware to soft wire. Some do well, some do not. What I have seen alot is the instant arrogance involved once they make transition. As far as programming goes, you can either think logically or not. Doesn't mean you are smarter than someone who can't. It doesn't take long to learn to program. The think that takes time to learn is the equipment we are controlling, not what we are controlling it with.
We all bring different perspective to the table. I've learned from the old guys that are locked into there standard template. I've also learned from newbies who have no templates, and just figured it out. Old guys loose arrogance, new guys, learn.