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crgwbr
07-14-2006, 01:55 AM
I have an industrail project going, and I need to know which to use. I've never used a plc before, but I use the BS2 all the time. Which is better for this sort of project?

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A.C. fishing
07-14-2006, 02:07 AM
PLC? Do you mean the PIC?? The BS2 is better. Maybe you will need an industrial version

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crgwbr
07-14-2006, 02:07 AM
No, I mean PLC, a in 'Programmable Logic Control'

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Kevin Wood
07-14-2006, 02:38 AM
Have you looked at the Stamp PLC?

www.parallax.com/detail.asp?product_id=30064 (http://www.parallax.com/detail.asp?product_id=30064)

Bruce Bates
07-14-2006, 03:27 AM
crgwbr -

It's hard to give you an answer without know A LOT more about your intended project. In my own experience I'd say I've been able to replace 65-70% of the OLDER PLC's with the higher functioning Stamps (BS-2sx, BS-2p?, etc). BUT, that's just my own experience.

Regards,

Bruce Bates

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John R.
07-14-2006, 04:32 AM
The question is not unlike asking should I use a pickup truck or mini-van to pickup some drywall from the local Home Depot.

Both will work, but the do the job differently, and will require you to do different things, and provide different benefits.

With the drywall trip, a pickup is "ready to go", drop the tail gate, load it up, and off you go. Fine, as long is it's not raining and you don't mind the ride of the truck. With the mini-van, you've got to take out the seats, maybe put down some plastic, and they you're set to go. But the drywall will be covered, and you'll have a smoother ride.

To your case, with a PLC you'll have a device that will deal with "industrial" I/O out of the box (voltage and current appropriate to the task). Programming might be a little less robust, depending on the PLC.

With a stamp, you'll need to do something for the power supply, and also deal with I/O conditioning, bringing input down to TTL/CMOS levels and taking the output back up to working levels. On the flip side, you may have a more robust and/or more appropriate programming environment.

It also depends on who will be maintaining the system. If it will be maintained long range by "electrician" types, the PLC may make more sense.

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John R.

8 + 8 = 10

steve_b
07-14-2006, 06:12 AM
what if I just want plywood?



John R. said...
The question is not unlike asking should I use a pickup truck or mini-van to pickup some drywall from the local Home Depot.

Both will work, but the do the job differently, and will require you to do different things, and provide different benefits.

With the drywall trip, a pickup is "ready to go", drop the tail gate, load it up, and off you go. Fine, as long is it's not raining and you don't mind the ride of the truck. With the mini-van, you've got to take out the seats, maybe put down some plastic, and they you're set to go. But the drywall will be covered, and you'll have a smoother ride.

To your case, with a PLC you'll have a device that will deal with "industrial" I/O out of the box (voltage and current appropriate to the task). Programming might be a little less robust, depending on the PLC.

With a stamp, you'll need to do something for the power supply, and also deal with I/O conditioning, bringing input down to TTL/CMOS levels and taking the output back up to working levels. On the flip side, you may have a more robust and/or more appropriate programming environment.

It also depends on who will be maintaining the system. If it will be maintained long range by "electrician" types, the PLC may make more sense.
http://forums.parallax.com/images/smilies/burger.gif

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Steve

"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."

John R.
07-14-2006, 08:21 AM
Then just strap it to the top of a VW Bug and you're good to go http://forums.parallax.com/images/smilies/smile.gif

I was thinking "apples and oranges" but that wasn't quite it either. Probably not the best analogy, but it was the best I could do on short notice!

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John R.

8 + 8 = 10

bennettdan
07-14-2006, 10:00 AM
Hey,
I work and program PLCs everyday they are rugged and really reliable, but I work with he BS2 some also and it very reliable also. PLC are pretty expensive and the software has to be bought seperate also most of the time.

steve_b
07-14-2006, 09:30 PM
Well, I think the analogy of the pickup and the mini-van is appropriate.

The PLC is a specific designed unit for industrial control...say like the pickup is designed to carry/haul stuff.
Where the stamp is good for interfacing/reading/controlling devices....not to the same extent as a PLC, but to some degree.....like the mini-van; it's designed to carry passengers but can also double as a cargo hauler, but just not to the same capacity as something specifically designed to do so!

;)

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Steve

"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."

stamptrol
07-16-2006, 04:12 AM
I do alot of work in the industrial field. PLC's, of course are the right choice for lots of digital I/O or very big systems ( like a sawmill where its easy to hit 10000 I/O).

Where the Stamp shines is down at the low I/O count projects where the small PLC's get pretty basic. If the project needs serial communication and low numbers of I/O, the Stamp will win nearly every time. You can see a few Stamp based projects on my site: www.siskconsult.com look under "projects".

Other factors may include the customer having a say in what hardware is used in his plant, who's going to maintain it , or whether the system needs some safety approval like Underwriters Lab or CSA.

Cheers

crgwbr
07-17-2006, 08:12 PM
Thanks Guys, I'm going to go with the PLC.

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