PLC MOV Instructions

I am a PLC student, and very experienced Electrician. For electrical maintenance type work, how far do I need to go into the programming of PLC's. Would I use the MOV Instructions, or Shift Register ?

I am looking at a possible employment in an Airport baggage conveyor system maintenance department. I would be assisting in PM, and troubleshooting, which includes the PLC.

dronai said:

Would I use the MOV Instructions, or Shift Register...in an Airport baggage conveyor system

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Yes.

Those are only just two of the more basic and common instructions in a PLC.

defiantly need to understand those commands. Mov is probably one of the most used commands besides XIC and XIO.

Ok good, so those are considered basic.

How much programming does a field Electrician need to know ?

I would think that you need to evaluate if the basic commands are executing, and maybe know how to Force an action. Any other thoughts.

Our site host, Phil Melore has also put together some good training material. Follow the links at the very top of the forum page.

Also one of our distinguished colleagues, Ron Beaufort has put together some online tutorials and youtube videos. Ron also runs one of the best PLC schools in the country. Go to his website http://www.ronbeaufort.com and find the sample lessons link on the left hand side. There you will find the various tutorials and youtube videos. Take a look at his training course offerings while you are there.

Alaric said:

Our site host, Phil Melore has also put together some good training material. Follow the links at the very top of the forum page.

Also one of our distinguished colleagues, Ron Beaufort has put together some online tutorials and youtube videos. Ron also runs one of the best PLC schools in the country. Go to his website http://www.ronbeaufort.com and find the sample lessons link on the left hand side. There you will find the various tutorials and youtube videos. Take a look at his training course offerings while you are there.

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I already purchased all of Phil's books,and Lab. Really good training, and easy to understand.

I was just wondering how far I would need to go into the programming, just to use it as a maintenance Electrician.

It looks like I might be getting this new job, so I need to be prepared. Also, the system they are using is Siemans Step 7, and I heard it's not like the AB I'm used to training with.

dronai said:

I would think that you need to evaluate if the basic commands are executing, and maybe know how to Force an action. Any other thoughts.

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At the places i have worked, it has pretty much worked where the electricians generally just "evaluate if the basic commands are executing." The most common issue is "function xxxxx is not working, let me see whats holding it out."

Thats all find in dandy in theory. All you need to do is just find the OTE for outpunt that operates that solinoid, valve, etc. and see whats not being made! Well, when you get into the real world, its alot more involved than that. You really need to understand most of the logic functions to truely understand why something is not functioning. There are usually several lines of logic that has to happen before an output becomes high. It is not as simple as contacts on a relay logic print.

It is impossible to tell you what you will and will not need to know. It all depends on where you work, what type of processes are being controlled, who was the original programmer, and many many other factors. The best thing i can recommend is to try to learn everything you can. Try to find a simple program/process and watch the program execute. Look through the code and read the help file for the commands you do not understand. The commands you use often will come to you quickly. You'll probably never completely understand every single function, but the main thing is be able to look it up in the help files and figure it out.

Much thanks for that Helliana. Yeah the "Real World" under the gun is going to an eye opener. This will be a large conveyor.

Will you be scheduled for Step 7 training or do you expect to have to pick it up on the job?

L D[AR2 said:

Will you be scheduled for Step 7 training or do you expect to have to pick it up on the job?

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I don't know all the details until next week. I will be under one other person, but when he is not there, I would have to handle problems.

While conveyor systems are basically pretty easy in theory, some can be complex. Since you said your project will "be a large conveyor", I'm curious if it's one large conveyor or one large system of several conveyors.

Obviously several conveyors have several motors and the programming basics will include sequential starting of the conveyors, beginning with the end conveyor first and the ending with first conveyor. Then each motor may have logic that has a defined control that is different that the rest of the motors--switches, sensors, etc.

Add to that, if necessary, any diverters, or pop-up stops etc., RFID or barcode sorting--any extras.

Also, make it a habit to keep safety in mind at all times. Conveyors usually have operators running around them. Plan your stops and E-stops properly and don't scrimp here.

Lastly, I try to build in as much in the way of self diagnostics that I can. If you have an HMI, it's very easy to build in screens that show faults or jams, either in text or in a bird's-eye view of the actual conveyor.

There's an abundance of help here so fire off any questions that arise and good luck!

Rube said:

While conveyor systems are basically pretty easy in theory, some can be complex. Since you said your project will "be a large conveyor", I'm curious if it's one large conveyor or one large system of several conveyors.

Obviously several conveyors have several motors and the programming basics will include sequential starting of the conveyors, beginning with the end conveyor first and the ending with first conveyor. Then each motor may have logic that has a defined control that is different that the rest of the motors--switches, sensors, etc.

Add to that, if necessary, any diverters, or pop-up stops etc., RFID or barcode sorting--any extras.

Also, make it a habit to keep safety in mind at all times. Conveyors usually have operators running around them. Plan your stops and E-stops properly and don't scrimp here.

Lastly, I try to build in as much in the way of self diagnostics that I can. If you have an HMI, it's very easy to build in screens that show faults or jams, either in text or in a bird's-eye view of the actual conveyor.

There's an abundance of help here so fire off any questions that arise and good luck!

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Thanks, Yes this is a large system of conveyors, with I'm sure all of the above items. I think there is an HMI fom my conversation with the person in charge of hiring. Keep in mind, this is now being designed/programmed, by someone right now.

Thanks for that comforting tip about people on here to give some advice. The electrical forums have been little help really.

Keep in mind, this is now being designed/programmed, by someone right now.

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Try and be as involved as you can!

If the system is being designed and built NOW it would be great if you could spend some time with the builders and programmers. This will pay huge dividends down the road if you're on the team who has to maintain it!!

Ladder logic is really easy to jump to from an electrician's standpoint--PLC manufacturers did us that favor. What can sometimes be challenging is figuring out how to get a desired logical result in the PLC software. You can want to do something, in your head, but how to get the program to accomplish that?

That part is what makes PLC programming fun.

dronai said:

...just to use it as a maintenance Electrician.

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Don't shortchange yourself as "just a maintenance electrician."

While your employer might not be expecting you to develop and modify the program he is certainly hoping that you will make yourself an expert in how the system works. The more you understand the program the more valuable you will be to your employer.

Bubba and Rufus have both tried really hard to understand the PLC programs. Bubba struggles with it more than Rufus but Bubba also works harder. Otis sees himself as "just a technican" and can't be bothered to understand the programs. Guess who gets the better reviews, higher pay, and more rewarding assignments.

Don't forget the resources here on the board as you learn about this new system and good luck with the new job.