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Most popular programable logic controller in the US?

J

Joerg

Jan 1, 1970
0
Hi Folks,

At c.a.e. I didn't get a lot or responses. Those of you who have dealt
with PLC units in industry: What is the most popular brand and type in
the US? Something that is cheap and practical.

Regards, Joerg
 
B

BFoelsch

Jan 1, 1970
0
As far as the installed base goes, Allen-Bradley PLC-5.

As far as current sales, Allen Bradley SLC-500.

These products are definitely for the American mindset, and are usually
(always in the case of the SLC500) programmed in ladder logic.

The more "engineering-oriented" users frequently prefer the Siemens product,
due to the ability to use statement lists and other programming approaches
more similar to current PC programming languages.

There are many other less expensive choices if you don't need more than
minimal networking capability.

What are you trying to build?
 
J

Joerg

Jan 1, 1970
0
Hi BFoelsch,
What are you trying to build?
Thanks for the Info. I'll check out Allen-Bradley. It is kind of tough
to find local dealers for PLC with pricing and all. As far as Google got
me, the AB stuff seems to be expensive versus some of the smaller
Siemens LOGO which start around $100.

First I might just try one out. The reason why I am looking is that
nearly all automation I was involved in was done with PCs. That works
nicely but it is often overkill and also it becomes increasingly
difficult to use a non-Windows OS. Drivers or the lack of them are one
of the issues here. A Windows OS isn't very conducive to reliable
unattended operation of machines, either.

The other very cost efficient option is always a micro controller but
many times that leads to a solution that is too much 'custom'.

Regards, Joerg
 
B

BFoelsch

Jan 1, 1970
0
Joerg said:
Hi BFoelsch,

Thanks for the Info. I'll check out Allen-Bradley. It is kind of tough to
find local dealers for PLC with pricing and all. As far as Google got me,
the AB stuff seems to be expensive versus some of the smaller Siemens LOGO
which start around $100.

First I might just try one out. The reason why I am looking is that nearly
all automation I was involved in was done with PCs. That works nicely but
it is often overkill and also it becomes increasingly difficult to use a
non-Windows OS. Drivers or the lack of them are one of the issues here. A
Windows OS isn't very conducive to reliable unattended operation of
machines, either.

The other very cost efficient option is always a micro controller but many
times that leads to a solution that is too much 'custom'.

Depending on what you are trying to do a PLC can make life very easy. Most
people who go the PC route on automation designs do it because they are
comfortable with a programming language or technique, but they totally
underestimate the difficulty of managing real world I/O, which is very easy
with a PLC. Secondly, very few, if any, PC- based solutions that I have seen
permit on-line editing. There is a great deal to be said ( in the industrial
environment) for the ability to make program edits while the program is
running, and again, this is pretty much standard for PLCs and pretty much
unheard of with PCs. And of course, the PLC operating systems are rock-solid
compared to the Microsoft offering.

Yes, the AB product is not the price leader, but it is the most popular,
most understood and most supported.
 
J

Joerg

Jan 1, 1970
0
Hi BFoelsch,
Depending on what you are trying to do a PLC can make life very easy. Most
people who go the PC route on automation designs do it because they are
comfortable with a programming language or technique, but they totally
underestimate the difficulty of managing real world I/O, which is very easy
with a PLC. Secondly, very few, if any, PC- based solutions that I have seen
permit on-line editing. There is a great deal to be said ( in the industrial
environment) for the ability to make program edits while the program is
running, and again, this is pretty much standard for PLCs and pretty much
unheard of with PCs. And of course, the PLC operating systems are rock-solid
compared to the Microsoft offering.
That is also what I have observed. There is another reason for a PC:
Everyone is familar with its file system and you can also write your
report right on it. No need to schlepp the laptop into a clean room
environment. Usually you can't take anything in there, or at least
shouldn't.

Online edit is possible though. We have done it when debugging
auto-bonders, laser cutters and so on. Single step, stop, manual head
movements to try something out, slow advance to see why a linear motor
didn't run smooth, it is all no big deal if the software can do that.
The OS was often non-Windows. There are some really good ones such as
QNX where latency times are very predictable. DOS, by the way, is also
rock solid and very frequently used in automation.

PLC would be even better but it does have to compete price wise. I am
pretty puzzled when I look at the distribution system. When I asked at
some local electricians places some didn't even know what PLC is. Others
said it can only be purchased through a 'few special outlets', whatever
they meant by that. One guy got so frustrated by the VAR runaround that
he bought his Moeller PLC unit through EBay.
Yes, the AB product is not the price leader, but it is the most popular,
most understood and most supported.
I assume they could do a lot more in sales if they were more available.
An example is our pellet stove. These have to run an auger, several
motors and must monitor 4-5 sensors. Low quantity products, the perfect
spot for a PLC unit. Yet they all go through the trouble of having their
own micro controller boards developed, something that just can't make
much sense in an industry where a few thousand units a year is a lot.

Regards, Joerg
 
N

nospam

Jan 1, 1970
0
Joerg said:
Hi Folks,

At c.a.e. I didn't get a lot or responses. Those of you who have dealt
with PLC units in industry: What is the most popular brand and type in
the US? Something that is cheap and practical.

I don't know if the company or the product is any good, but, if I were in
the states and looking for a cheap practical range of PLCs that are easy to
buy I would try http://www.automationdirect.com
 
J

Joerg

Jan 1, 1970
0
Hello,
I don't know if the company or the product is any good, but, if I were in
the states and looking for a cheap practical range of PLCs that are easy to
buy I would try http://www.automationdirect.com
Thanks. I had looked at those but they do get expensive if you want to
configure them to what I'd normally expect in a PLC controller. For
example, while the DO-05RR retails for $99 it has no realtime clock.
This means you can't really control much with it unless it is networked
and even then I'd want it to be able to run on its own. Just the
addition of a realtime clock will tack on another cool $47.

Regards, Joerg
 
R

Rene Tschaggelar

Jan 1, 1970
0
Joerg said:
Hi Folks,

At c.a.e. I didn't get a lot or responses. Those of you who have dealt
with PLC units in industry: What is the most popular brand and type in
the US? Something that is cheap and practical.

While not having worked with them, I got the impression that
the siemens Logo is trivially simple to operate and rather cheap.
They sell them for 120$ at overpriced distributors in quantities
of one here.

Rene
 
Y

YD

Jan 1, 1970
0
Hi BFoelsch,

That is also what I have observed. There is another reason for a PC:
Everyone is familar with its file system and you can also write your
report right on it. No need to schlepp the laptop into a clean room
environment. Usually you can't take anything in there, or at least
shouldn't.

Online edit is possible though. We have done it when debugging
auto-bonders, laser cutters and so on. Single step, stop, manual head
movements to try something out, slow advance to see why a linear motor
didn't run smooth, it is all no big deal if the software can do that.
The OS was often non-Windows. There are some really good ones such as
QNX where latency times are very predictable. DOS, by the way, is also
rock solid and very frequently used in automation.

PLC would be even better but it does have to compete price wise. I am
pretty puzzled when I look at the distribution system. When I asked at
some local electricians places some didn't even know what PLC is. Others
said it can only be purchased through a 'few special outlets', whatever
they meant by that. One guy got so frustrated by the VAR runaround that
he bought his Moeller PLC unit through EBay.

I assume they could do a lot more in sales if they were more available.
An example is our pellet stove. These have to run an auger, several
motors and must monitor 4-5 sensors. Low quantity products, the perfect
spot for a PLC unit. Yet they all go through the trouble of having their
own micro controller boards developed, something that just can't make
much sense in an industry where a few thousand units a year is a lot.

Regards, Joerg

I've never used a PC based control system, but I understand they're
pretty slow and have high latency, a no-no in the industrial
environment. Until now we've been using AB SLC-500, but they're
getting too expensive so last week I set up a Siemens S-200 for a
trial of an app where the AB's are too slow. Hey, it's fantastic,
almost no latency and lightning fast response. The programming
environment (Step-7) is easy to use, instant switching between ladder
logic and symbolic language makes it a lot more readable depending on
if you're doing a bit of logic or some calculation. They're a lot
cheaper too.

The application in question is a hot melt spigot, it needs to start
the sequence in at most a ms from the input closure and run with a
resolution of a few ms to get the glue spots in the right place.

If you need it operator controllable/adjustable or generate reports
you'll need some sort of supervisory system communicating to it on a
PC. We use FIX/DMACS currently but it too is getting too expensive and
a bit behind the times.

Get your ass over to the Siemens website and do a read-up.

- YD.
 
J

Joerg

Jan 1, 1970
0
Hi Rene,
While not having worked with them, I got the impression that
the siemens Logo is trivially simple to operate and rather cheap.
They sell them for 120$ at overpriced distributors in quantities
of one here.

Over here it's worse. Tried Google and other searches but no place to
find where they have a price list. Before I evaluate any options I
always want the cost first, to see if it makes sense at all.

Then last week I tried it through the Siemens site. Keyed in all the
info they wanted, plus a question where to buy LOGO and other stuff. No
answer. That's not a good thing.

Regards, Joerg
 
J

Joerg

Jan 1, 1970
0
Hi YD,
I've never used a PC based control system, but I understand they're
pretty slow and have high latency, a no-no in the industrial
environment.
Unless you use a realtime OS which makes latency predictable. We had
done one with QNX and it was very reliable.
Until now we've been using AB SLC-500, but they're
getting too expensive so last week I set up a Siemens S-200 for a
trial of an app where the AB's are too slow. Hey, it's fantastic,
almost no latency and lightning fast response. The programming
environment (Step-7) is easy to use, instant switching between ladder
logic and symbolic language makes it a lot more readable depending on
if you're doing a bit of logic or some calculation. They're a lot
cheaper too.
I wasn't even able to get a price list from a California vendor for
SLC-500 and considering that such searches take a mere 10 seconds with
any other electronic part that made me wonder a bit.
Get your ass over to the Siemens website and do a read-up.
Been there last week. Nice pictures and all but after diligently filling
out their web form and asking for sources here in California I did not
get any answer from them. I would expect that such simple requests are
handled same day. This didn't raise my confidence level.

Regards, Joerg
 
F

Frank Bemelman

Jan 1, 1970
0
Joerg said:
Hi Rene,


Over here it's worse. Tried Google and other searches but no place to
find where they have a price list. Before I evaluate any options I
always want the cost first, to see if it makes sense at all.

Then last week I tried it through the Siemens site. Keyed in all the
info they wanted, plus a question where to buy LOGO and other stuff. No
answer. That's not a good thing.

Farnell has them:
http://uk.farnell.com/jsp/endecaSea...t=siemens+logo&Nty=1&N=401&Ntk=gensearch&y=10

Which means you should be able to order them through Newark too.
Price is ~88 uk pounds. The cheaper ones (77 pounds) don't have a
display and can only be programmed via PC and software.

Another place to look might be Ebay in Germany. Here's one,
including a power supply 120/240VAC :

http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&category=57517&item=3848227357&rd=1

Runs 11 hours, no bids yet. 49 euro, that's about $65. Hmm,
might go for it myself ;)
 
F

Frank Bemelman

Jan 1, 1970
0
Frank Bemelman said:
Farnell has them:
http://uk.farnell.com/jsp/endecaSea...t=siemens+logo&Nty=1&N=401&Ntk=gensearch&y=10

Which means you should be able to order them through Newark too.
Price is ~88 uk pounds. The cheaper ones (77 pounds) don't have a
display and can only be programmed via PC and software.

Another place to look might be Ebay in Germany. Here's one,
including a power supply 120/240VAC :

http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&category=57517&item=3848227357&rd=1

Runs 11 hours, no bids yet. 49 euro, that's about $65. Hmm,
might go for it myself ;)

Also have a look at:
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&category=57517&item=3848126224&rd=1

The KLÖCKNER MOELLER Easy PLC's are practically the same animals.
 
J

Joerg

Jan 1, 1970
0
Hi Frank,
Farnell has them:
http://uk.farnell.com/jsp/endecaSea...t=siemens+logo&Nty=1&N=401&Ntk=gensearch&y=10

Which means you should be able to order them through Newark too.
Price is ~88 uk pounds. The cheaper ones (77 pounds) don't have a
display and can only be programmed via PC and software.
It seems to be easier to buy PLC units in Europe. I checked Newark and
Digikey for the Logo. Zilch.
Another place to look might be Ebay in Germany. Here's one,
including a power supply 120/240VAC :

http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&category=57517&item=3848227357&rd=1

Runs 11 hours, no bids yet. 49 euro, that's about $65. Hmm,
might go for it myself ;)
That is great but I don't want to get involved with a technology when
EBay is the only practical way to buy stuff.

Regards, Joerg
 
F

Frank Bemelman

Jan 1, 1970
0
Joerg said:
Hi Frank,

o&Nty=1&N=401&Ntk=gensearch&y=10
It seems to be easier to buy PLC units in Europe. I checked Newark and
Digikey for the Logo. Zilch.

Yes, it is strange you can't get them. The Siemens logo is not on
Newarks' website, but I thought they should be able to sell you items
from the Farnell catalog.

For quick solutions there's also the stuff from Zworld, but these are
programmed in C and cost a lot more.
That is great but I don't want to get involved with a technology when
EBay is the only practical way to buy stuff.

Well, you only have 1 swimming pool I guess. Or did you need
more?
 
Y

YD

Jan 1, 1970
0
Hi Frank,

It seems to be easier to buy PLC units in Europe. I checked Newark and
Digikey for the Logo. Zilch.

Strange, here we just call a representative and they'll skip, hop and
jump over with a catalogue. And we're half-way out in the boondocks.

Siemens even loaned us a LOGO and an S-200 for testing, complete with
cable and proramming software. They won't regret it, we'll need 5
basic S-200s and one with a rather large amount of expansion modules.

The total amount spent will be just about the cost of a basic SLC-500,
go figure.

- YD.
 
J

Joerg

Jan 1, 1970
0
Hello Frank,
For quick solutions there's also the stuff from Zworld, but these are
programmed in C and cost a lot more.
Yes, but then I might as well buy an MSP430 board and roll my own.
Well, you only have 1 swimming pool I guess. Or did you need
more?
This was just to try it out and I wouldn't leave it in there.
Controlling that is rather easy with off the shelf timers and stuff. I
am looking for something that can be used for machine automation, for
things that we do with PC architectures so far.

Regards, Joerg
 
J

Joerg

Jan 1, 1970
0
Hi YD,
Strange, here we just call a representative and they'll skip, hop and
jump over with a catalogue. And we're half-way out in the boondocks.
That is the 'classic' way, the same way it used to be with parts,
databooks, samples. You had to call a distributor and they'd come over.
But this isn't the way the business works anymore, at least not in
electronics. Now I simply go to the TI, National, ON Semi or whatever
website. Within seconds and without waiting for a call back from a rep I
can obtain pricing, all the data sheets I want and order samples for my
prototyping. Some European companies still cling to the old world method
and all it says is 'call distributor'. That is why my design-ins for
products from those companies have diminished to a trickle.
Siemens even loaned us a LOGO and an S-200 for testing, complete with
cable and proramming software. They won't regret it, we'll need 5
basic S-200s and one with a rather large amount of expansion modules.

The total amount spent will be just about the cost of a basic SLC-500,
go figure.
How much did these five basic ones cost you per unit?

Regards, Joerg
 
Y

YD

Jan 1, 1970
0
Hi YD,
How much did these five basic ones cost you per unit?

Not me doing the buying, and I can't recall of the bat, but I believe
R$2000 was mentioned. At the current exchange rate that's about
US$600. Much of that is due to taxation at an incredible rate.

- YD.
 
J

Joerg

Jan 1, 1970
0
Hi YD,
Not me doing the buying, and I can't recall of the bat, but I believe
R$2000 was mentioned. At the current exchange rate that's about
US$600. Much of that is due to taxation at an incredible rate.
$600 per unit? Ouch. You guys must really pay outrageous taxes because
at that price you can install a leather-seat and marble PC solution. At
least in the US.

Regards, Joerg
 
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