Anyone here work with PLCs and automation?

[Dave Shepard]

I'd like to learn about PLCs and automation for a project I'm working on. I have some friends that do some of this type of stuff, and will ask them but I may not see them for a while. I'm looking for any websites or good books on the subject. I have a lot of questions, but also a lot of time to learn this. I have an old Automation Direct catalog that I've been perusing, but not knowing the terminology, it makes it hard to know what is compatible or required for a working system. The machine I am designing will have several different components that can be operated individually at first but will have to be integrated together at some point.

Some of the operations that need to be controlled:

AC motors
Gearboxes with stepper motors
Photo electric eyes
Air cylinders
Counters
Limit switches

Any advice would be appreciated. I'm going to see if there are any courses offered in this, but I doubt there will be in my area.

[Jim_Rogers]

You may need to define "PLC" for those of us to don't know what that is, like me.

Jim Rogers

[Dave Shepard]

Programmable Logic Controller.

[Jim_Rogers]

Programmable Logic Controller.

thank you for that....

[Compensation]

I would suggest getting a slk500 and rs logics software. The first time I got hold of that, it was about 12 hours later I had a simple stop light programed. Another 4 hours I had a conveyor offloading program made. Then it progressed to air/hydraulic production system I built. The whole time was exciting just learning what all you could do. So that's why my advice is to just jump into it and use lights and push button switches as indicators to play with. Also don't get discouraged when you get a fault that locks up a process. Like the stop light I made ran 3 cycles then locked up. Simple fix but frustrating.

[beenthere]

PLC
http://www.amci.com/tutorials/tutorials-what-is-programmable-logic-controller.asp

Maybe time for a class or two if you can find one, and include your project (or a part of it) in the classwork.
The trial and error as suggested would be a good way to learn too.

Wasn't it hackberry jake that took a class and developed some numerical control devices?

[Dave Shepard]

Thanks for the replies. I found a YouTube channel called plcprofessor that has a series of videos on programming a PLC. I'm just starting to watch one now that us using a basic rs logics software to program a garage door opener.

[Den Socling]

My son runs the control business and he recommends VisiLogic http://www.unitronics.com/support/downloads for people who want to look into programming PLC's.

[red oaks lumber]

whatcha buildin dave?

[r.man]

Beware software. I have run into two systems recently that were turn key programmed machines. Both were missing the PLC ladder diagram and to download and manipulate it you must buy the software to the tune of 6 to 8 hundred dollars. The PLCs are the cheapest part of the equation, check to see how expensive the software is before buying the hardware. For those of you that don't know a PLC is just a basic computer brain designed specifically to accept information mostly in the form of on or off like a switch and then to turn on something based on the information. A simple example is a switch that tells the PLC to turn on a light. The advantage comes from the ability of the PLC to do complicated things as well. When you turn the switch on you could have the PLC pulse the morse code for S O S until the switch is turned off or any number of complicated jobs that would have taken multiple hard wired relays and a complicated wiring array.

[Dave Shepard]

whatcha buildin dave?

Just looking to automate some cut to length operations. Nothing too exciting. It won't revolutionize the industry, but certainly will revolutionize my operation. :D At this point, my operation is a one man show, and will stay that way. The jump in productivity needed to have employees is huge, and I'd rather build a machine to help me make some these products faster, and if there is no need to run the machine, it doesn't cost me money if I don't run it. The other part of this is the challenge of learning something new. I have been around machinery run by PLCs and I can see how they can really change productivity. I have had some ideas in mind for down stream material from the mill as well that would greatly increase my mills productivity simply by taking the material away from the mill and sorting slabs from boards, as well as flitches from boards to be edged. That equipment will have to wait until the mill is in a building and on concrete. No sense building all that out in the snow and mud.

[jcbrotz]

What software are you planning on using? In a past life I was programming several of these systems at Old Proctor, Before I had enough of the politics and educated idiots in charge.

[Dave Shepard]

I don't know what software yet. I need to know enough about this stuff to know what software will work with which PLC.

[jcbrotz]

It will come down to the functions you want to do, RSlogics was used a lot there for controls with the right output controller you could do most anything you could think of. How many function you thinking of? measurements would be your biggest issue $$ wise as you would need some extra cards/input devices for the lengths. Could probably do it with photo eyes but then you would have to move them repeatedly.

[Dave Shepard]

I'm hoping to do the measuring with the stepper drive on the feed rolls. Run the board in until it hits a photo eye, trim, then the stepper motor would run the rolls in the right number of turns for the selected length. Not sure if I'm using the right terminology. Perhaps it's simply a gearbox with an encoder on it somewhere with a drive of some sort. I'm not looking for .001" accuracy.

[Den Socling]

It sounds like you need to tie an encoder to a PLC. That's not hard to do.

[Den-Den]

I did some of this type work in the oilfield in the past.  RSLogix software with Rockwell hardware is my favorite to use but is expensive.  I would look closely at Automation Direct for this type of equipment.  Be careful about surge protection; an lightening strike can burn up some expensive equipment and cause downtime.

[pineywoods]

I have the desire, but not the time. You need to hook up with hackberry Jake and Arnold113. Jake has a homemade cnc router and homemade setworks on what was once a manual bandmill. Both use off-the shelf hardware and software.  Arnold113 is putting together a homemade bandmill with a very sophisticated setworks, almost completely automated. Both of these guys have offered to share information..

[21incher]

If you are going to use a stepper motor you will need a motor drive such as a Gecko and can tell it how many steps to move if you know distance per step, or run it closed loop with a encoder to know how much to move. I designed and built a cnc plasma table using servos and encoders that interface thru Rutex drives to a old PC with XP and a parallel port. The machine control is using a cam program called Mach 3 that sends signals for the step and direction control and monitors the table I/O. There is newer hardware that will interface through Ethernet and newer windows versions, but I think a old PC is a good cheep machine controller to start with and many low cost I/O boards are available for machine control. There also are some Arduno kits out there that may be adaptable to your requirements.

[Al_Smith]

Since you've asked it's how I make my living .At the moment it's Telemecanique PL7 and ABB robotics.Prior to it was all kinds of Modicon controllers up to the 984 .I've worked with just about every system used in major industry .I'm knowledgeable but I certainly am not an expert .

Although they are old if you could find one a Modicon micro 984 is a nice controller .The problem might be finding the software to be able to access and program it .

[jcbrotz]

The system you describe should be pretty simple to do. Toward the end at proctor we were transitioning everything over to rslogics it programs easy and is very adaptable for all types of inputs, but pretty pricey. Encoder inputs and drive motors would be simple to set up with this system, I will have to see if I can boot my old computer and see if I can still get into the old software now, I thought I would keep it for a rainy day incase I wanted to do something similar.

[r.man]

For economy used might be a good option, older controllers are bulkier which should not be a problem and you might be able to get a free copy of older software and then buy used controllers to match. There is a lot to be said for older stuff that has a good track record.

[Al_Smith]

Something to keep in mind is the fact certain stepper motors,servo motors and the like only run on specific controllers made for a praticular application .Some can be infaced with a small PLC and some it would require other additional components .

Add to that the fact that often the required voltages are not the same as used in North America .For example some Japanese systems  require 200 volt 3 phase which would require a special transformer and a host of other components .If you don't watch it you can paint yourself into a corner with this stuff .

I deal with this stuff all the time at work.However it's a multi national company with billions and billions of dollars and a huge staff of electrical engineers not a small sawmill operation on a limited budget .Remember the KISS principle . ;)

[dmartin]

I have worked as a controls specialist for many years in the industrial gasses / air separation business. I have worked with Allen Bradley. Texas Instruments, Siemens, Fanuc, and some others. They all have good products and some are much easier to work with than others. The major drawback with them is cost as all of them are expensive because big industry can afford it. You mentioned Automation Direct and I always thought if I ever need to PLC for any of my own projects that I would buy from them. Look around their website much info on learning and products for sale at reasonable prices. I personally would recommend the Direct Logic PLCs on there website as they are very common and reliable. Some of our vendors of stand alone equipment that we have bought use them and they are never any trouble, also they are easy to communicate with using our HMI interfaces. Take a look at their and you will find many links for learning. Here is a link to the direct logic line of PLCs that they sell.
  http://www.automationdirect.com/adc/Overview/Catalog/Programmable_Controllers/DirectLogic_Series_PLCs_(Micro_to_Small,_Brick_-a-_Modular)

[boardmaker]

Having used Allen Bradley SLC500's, CompactLogix, ControlLogix, and MicroLogix, as well as Automation Direct DL06's, DL305's, and their new platform the DoMore.  My recommendation is for the DoMore.  It is a much more capable PLC. Communication with the PLC is easy and very straightforward. The software for the DoMore is free.  If you would go with the older DL line you will have to purchase the software.
Automation Direct's tech support is top notch and they have a forum where most questions have already been answered.

I love Allen Bradley and those are the PLC's I cut my teeth on, but AB is very pricey.  They are the best as far as I'm concerned but hard to justify the price when the project can be completed with a much lower cost PLC.

If it were my personal project and my checkbook, I would go with Automation Direct and the DoMore PLC. 

[Dave Shepard]

Thank you. I've heard the same about AB, great stuff but pricey. I've been leaning towards Automation Direct, good to be pointed towards the right combination of software and controller. I talked very briefly to a friend that uses PLCs tonight. He has Toshiba's, which he is happy with, but I don't see them pop up too often in PLC discussions. AD seems to have a complete package with all the goodies available under one roof, so to speak. I think the worst part of this whole project is having to buy a laptop with Windows. :D

[hackberry jake]

The class I took was called "Intro to programming logic" and I thought I was taking it to learn about plcs but it ended up being a C++ computer programing language class. The C++ language is how people program computers. I know very little about plcs. I use Arduinos in my projects and they are capable of doing everything you mentioned. An Arduino Uno can be had for $25. It has 20 I/O ports for controlling various things. If you need more than 20 (and I figure you will) I would get an Arduino Mega for $46. I think the mega has 70 or so I/O ports. The only software needed to control it is the Arduino Development environment and it is free. The programming can be tricky, but they have some drag and drop type software available for people that don't know how to program in C++. As far as measuring distance with a stepper motor, it would be pretty easy to do. Just have the stepper motor step one step at a time and each time it repeats, have a counter increment by one. Once the board disrupts the photo eye, the arduino would take the counter and perform a math function to find the distance.  As far as controlling AC motors, solid state relays are getting pretty cheap now days.
If you need any help programming just let me know. If you don't want to mess with the programming, I could probably work on it for you for free. I need the practice and I kind of enjoy in. It is like a really long logic puzzle that you make yourself.

[Dave Shepard]

Thanks for the offer Jake, but I think I'm going to stay on the PLC path. That is the most common automation that I am exposed to, and also what the people I'm going to pester in person are most familiar with. ;D A large part of this project is about learning the PLCs and the automation of the equipment. I need to do something to stimulate my brain. Stacking boards by hand is so 2006 for me. :D

[Al_Smith]

Oh it will stimulate the old brain allright .You get into DFB's,shift registers, first in first out and stuff like that you'll wish you had a cabinet full of relays and timers .

You can program a PLC to make it do anything you are comfortable with .Depending on the type and software of course .

Programed in simple relay logic if you are familiar with relays it's relatively simple .You get to infacing and combining sytems like controling a DC servo motor it gets complicated quickly .I've more that once seen 3 electricians  including myself who are trained on this stuff with three more highly educated controlls engineers all scratching our heads .

[WoodenHead]

This is an old thread, but it touches on something that I have been pondering for a while.  I would like to automate board stacking coming right off the mill.  I too am a one person operation and would like to keep it that way.  I have minimized my handling as much as I can.  Yet, it would be nice to combine the task of stacking with moving material away from the mill (without sacrificing milling time). 

Were you successful in getting something together Dave?  Has anyone else come up with something for this?

[Dave Shepard]

I haven't pursued it very much lately, but I'd like to. Maybe when I get a few other projects out of the way.

[Stuart Caruk]

PLC's are simple to program. Automation Direct sells a Koyo PLC which is used by many major manufactures. It's less than 10% of what you would pay for say an Allen Bradley system, but you do get what you pay for. If you don't have a high electricla noise environment or use shielding they work just fine.

You will need to either download their free programming software (with limited functions) or spend around $250 for a more robust version of software. With any PLC you are going to need to know how to program it.

If you want to learn the basics for cheap. Go to parallax and grab a basic stamp programming kit. Or go to the Makershed and pick up a Arduino programming kit.

Once you know how to program a microcontroller, the ladder logic programming of a PLC is easy to learn.

And for those who don't know what a PLC or a microcontroller is, it's a great thing to learn. Think of it as a very easy to program relay or switch that you can make do whatever you want based on what you can connect to it's inputs and outputs.

FWIW, if you have kids, they should all know how to program a microcontroller. If not, they are functionally illiterate in our computerized age. Virtually everything with a digital signal in is has some form of microcontroller running it.

[Kbeitz]

I'm kinda lucky that I live not to far from a junkyard that gets PLC's and VFD's in all the time from
a food Processing plaint. I love to tinker. Some of the stuff I get is new. When they change a food
line over to something different everything gets tossed out and all new come in. So any backup
supplies goes with everything else out to the yard. I do a search for the model number and add PDF
to the search to find the manuals to the equipment. I have a ton of fun learning and playing. I know
the stuff I find cost $1000's The last VFD I got is over 2 feet high. I wanted to put a PLC on my mill
but I like it simple and I don't think the PLC would take the cold and damp very well. I also love playing
with digital computer relay input output  boards. I made my own CNC machine and did all the programing
for it. Some of the time the PLC manuals will have sample programs in them that helps a lot for learning.
I made a lot of money selling Nema contactors  3-4 and 5's thats mixed in with all the junk.

[Al_Smith]

It's relatively simple if it's in "relay logic" .Once you get into defined function blocks, shift registers, interface with robotics etc it gets a tad complicated .

PLC's it seems have planned obsolescence just like computors .Every so often they just get to the point they have no factory support then major industry must upgrade and it's not cheap .Fact at work for the last 6 months it's been going on and probably will be another 6 months before it's all done .It really never ends .----and I never stop going to school on the danged things .Geeze I no sooner get comfortable with an operating system than they change it on me .