Most Common PLC Use?

... setup plc to send tease emails to IT guys and play hide and seek.
how long till they figure out it was not sent from any of the PCs?

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Put a password on the program as well so that they cannot get in and stop the messages. Tickles my rotten sense of humour.

No Hardwired E-Stop?...

Rich1955 said:

I found a better example

This is an AD 6 slot, 240 CPU

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Whether or not this is overkill, I'd definitely agree with the 'misuse' part. Look at the first rung:

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Let me guess... The emergency stop button is ONLY connected to X1?...

beerchug

-Eric

there's a farmer here in ohio that has a micrologix 1000 setup to feed his hogs. it runs a feed mixer, opens and closes trough gates, and runs augers on a programmed schedule. it even regulates drinking water level for the pigs. not sure which pig did the programming though.

Eric that whole program makes no sense considering its just 7 rungs. I think the E-stop, possibly from the complete system may be powering a power relay for this system.

What I dont get is the Selector Switch that is an output: Rung 2
What does this switch do?

Why use the JMP?

Undoubted this system is PART of a more complex system that wasnt purchased or isnt being used.

Personally I would be looking at incoporating other parts of the paint system with the spray system.

I wouldnt care which PLC was used but would like the program, wiring etc to make sense.

rsdoran said:

What I dont get is the Selector Switch that is an output: Rung 2
What does this switch do?

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The output might possibly turn on the sprayer. Probably goes to the common of a selector switch to select different spray heads...

rsdoran said:

Why use the JMP?

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That's the same question I keep asking Bob H. (testsubject)...

beerchug

-Eric

PLC and eggs

Could you not use a PLC and a photo sensor to candle eggs? Somebody / somehow it has to be done.

How do you feed and water the chickens or keep the henhouse coool or warm??

And what do you do with all that CS?

A little OT

There are a lot of chicken and egg farms in my area. They are very automated. Light controls (chickens are up 20 our of 24 hours), ventilation, feed systems, heating, cooling etc....

what do you do with all that CS?

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One of my co-workers owns two chicken houses also, according to him, it is washed out every day and placed in bladders. Once the bladder is full they close it off and let it decompose. The bladder expands like a ballon, when it gets to a certain point, the gas is siphoned off and used for heat. The final decomposed product is then sold for use in mushroom compost.

Ken

To answer the original question first, I would have to agree with many in that their primary use is to replace relays, timers and counters. As for a specific application, pumping systems do come to mind, but generally speaking, machine automation.

I get asked by people who are looking to work with us, what industries do you focus on...I have to tell them, there is no one industry or application. The only limitation is your mind, when it comes to using this type of product.

I am talking with a potential customer that was using an AD05, about using our product. The conversation first started off as "I'm interested in your product, this is what we are using, what is your price? The conversation evolved, into...can you add this, can you do this...and their application grew out of the DL05, because we looked at both wants and needs.

We have a customer, that uses one of our products to retrofit an old milling machine that is no longer produced. The original design uses many large GE relays. The panel size is approximately 8 feet high and 5 feet wide. The ePLC they use, takes up a fraction of the space and uses 48 inputs / 40 outputs.

We have customers that will use our product for only a couple of relays and a timer. The reason being, once you done the program, all you are doing is wiring a circuit board and your application is done.

Rich,

It isn't as much the missuse of PLCs as it is the inadequate capabilities of PLCs. When you use a PLC with relay outputs, there are restrictions (common restriction and output restriction) Typical relay output modules for PLCs tend to average 2 amps per output. This is fine for small solenoids, lights, requiring small currents to activate. In some instances, interposing relays are highly recommended, for devices such as motor starters, that generate a substantial inductive load.

Not all PLCs are created equal when it comes to their capabilities. That is why you must do your research to find the product that best fits your application, from a performance and cost standpoint.

Someone mentioned farmers and eggs...we actually have a customer that does an egg wash system.

God Bless,

PLC Use

At least in our plant, the biggest reason for PLC's is communication. They give you the ability to use one co-axial cable for interfacing between two systems rather a bunch of wires. Also, where we used to have more workers walking around checking flashing lights, bells and horns, now we have less workers because the PLC's talk to the Wonderware, which in turn sends any systems alarm conditions to the pager's which are carried by the few people left.
I love working with PLC's, but a lot of jobs have been eliminated by them.

Everywhere there is a large amount of conveyor, there should be a PLC. Same for Packaging or Manufacturing. Same for automated batching. PLCs save time, space, and money.

PLCs cost way too little up front to not use them. Diagnosis and expansion are much easier with a PLC. Inform your inventor friend that it's the 21st Century and he needs to get here if he isn't already. He'll probably like it.

rsdoran...

Ron,

you wrote

"At the cement plant I used a cheap "brick" to replace a specialty "timing" board
PLC cost $150
Board cost to repair $350 to 400, couldnt buy new."

Was that a dust collector blowdown timer board?


Brian.

panic mode said:

... setup plc to send tease emails to IT guys and play hide and seek.
how long till they figure out it was not sent from any of the PCs?

Click to expand...

BobB said:

Put a password on the program as well so that they cannot get in and stop the messages. Tickles my rotten sense of humour.

Click to expand...

This has just given me a thought for tomorrow

RUBE wrote:

Inform your inventor friend that it's the 21st Century and he needs to get here if he isn't already. He'll probably like it.

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He is 24, and hasn't played around with PLC's yet. A lot with electronics, tube amps and equipment, and has designed a lot of mechanical devices. One being a really nifty car battery service and carrying tool. Another is a fold down ladder rack for a pick up truck.

He saw an Entertron SmartPak on my desk, and I had mentioned what I was going to do with it. So now he has some interest in inventing something that uses a PLC. So far, he hasn't come up with anything yet. He thinks he can find something that's never been done before.

An automatic Egg Candler, with a mini-conveyor, fertile and non fertile sorting, chute release, etc could be something to start with. Wouldn't cost much to do.

Hey, I just thought of a great project for him to learn PLC basics, while he tries to come up with a machine to invent. The SmartPak has relay output contacts rated at a hefty 7 amps. He has a 71 Mustang, and has thought about adding two more tail lights on each side, kinda like the mid 60's Corvettes. So why not set up a 12 volt PLC for sequential tail lights, like the '64 (etc) T-Bird had! The contacts will easily handle the 2 or 2-1/2 draw of the bulbs, six outputs, six lights. One input can be for brakes, one for sequntial "ON", one for "NORMAL" on, one for "Razzle Dazzle", one for LEFT, one for RIGHT. I think I 'll teach him to program on my computer, and he can run the simulator to see it work, without having to get a PLC. Does he really want those sequential lights? Time will tell. Cut holes in a semi-classic??? If he decides to go with it, the SmartPak price won't break his budget, and it is a whole lot chaper then a surplus T-Bird or Lincoln flasher (read Motor Drive switch). He can always use it on a machine when he gets it invented.

I wonder if there is a market for an automatic Egg Candler?



STEPHEN:

Please give a raise to the person that came up with the idea of putting the heavier outputs in your products. They extra ampacity is nice to have when you need it, even nicer when you don't have to pay extra.



regards.....casey

Sliver it was part of a bagging process, the boards time air to clean out the spout after fill. They also timed the process...ie bag took too long to fill then STOP. There were 4 timers altogether but cant remember what the other 2 did. Whats crazy is the system had a CH D100 with expansion that was full.

Casey--

Whenever I have to instruct a beginner, one of the things I do is program any of the outputs on an output card using the card's LED as a visual aid. There's no risk of breaking anything or hurting anyone and timers, counters, just about any basic instruction can be used to control the LED. Your friend sounds pretty adaptable--maybe something like this could be a springboard to his first million.