Industrial Motion control

W

Thread Starter

William Sturm

In the years past, it was hard to find a popular brand
PLC that had decent integrated motion.

By popular brand, I mean a PLC system that most Fortune 500 companies would accept in their plants.

By decent, I mean master/slave, cams, multi-axis interpolation, parametric motion, easy integration...

Here is what I have seen recently:

A-B has their ControlLogix with multi-axis motion
programming in ladder logic. They are using Sercos to
digitally interface with their servo drives. They offer multi-axis slaving, cams, and interpolation.

GEFanuc has a digital two axis servo module for their
90-30 PLC. It has a digital interface to their servo
drives. They offer multi-axis slaving and cams. They
use the two CPU approach, where you have a sequential
motion program controlled by bits and words transferred from the ladder CPU.

I do not know much about Siemens approach. They have
a system called Simotion D which looks suitable. It
appears to use a mult-axis digital drive system intefaced to their PLC's via Profibus.

I know even less about Modicons offerings. They appear to have something called Quantum Motion Control. This uses Sercos for multi-axis control.

I am not counting the many motion board manufacturers in this quest. I use many of their products, but they are not well integrated with PLC's and are not well accepted by the larger plants.

I am looking for a good clean slate approach, without
carrying forward all of the baggage and shortcomings of the older systems. Is this available today?

Are most PLC based motion using ladder based function
blocks to program motion, or is the two programs with
handshaking still predominate?

There is the classic problem of combining a continuous
scanning ladder process with a seqential motion program. Has this been solved by IEC-1131 and multiple languages?

I'm not looking to start a flame war. I just want to
find out what is being successfully used these days and why. I want to quote PLC based motion systems to my current customers. I work for a small company and cannot afford an expensive false start by choosing an unruly solution. Been there and done that.

Thanks for any and all advice.

Bill Sturm
Applied Grinding Technologies
 
I've used the controls on your list, but my favorite (in terms of usability, performance, price, and support) is G&L (Giddings & Lewis).

Don't dismiss them because the name isn't as big as Rockwell or Siemens. I've placed their units in fortune 500 companies on many occasions.

My typical application with them is an 18-axis SERCOS machine (any SERCOS drives, but I used Indramat), with gearing, camming, and registration. One processor handled it all very well, at a price point much better than Rockwell.

Support is good with a knowledgeable and helpful phone support group. No, I don't work for them, I just really like their product.

check http://www.glcontrols.com/ie/default.asp for more info.

That's my 2cents worth,
AC
 
First i am no salesman, but i have been in controls engineering for over 25.

The best solution of the type you are looking for that i have seen is from Yaskawa. They off a Product called an mp-940 that has a built in PLC. No it is a true PLC with motion integrated directly into the system itself. You can do real PLC logic (not the silly stuff most robot and motion controllers call PLC Logic). The motion can be programmed in real time register based motion, Motion control blocks, or Motion progam based. The register base is as simple as it gets and looks no different than any other code in the PLC. All gearing, camming, ect.. can be accoplished this way. The motion blocks afford a table or graphical base in which to write motion and is called like an A/B timer. ie.. Start signal returns a running (TT) and complete (DN) type signals back. The register assignment can be monitored and compared for all types of logic. The motion can also be written in motion control language. Basic language type interface. These programs are called directly from the PLC code.

The M9-920 Is the same as the MP-940 but is a complete control system. Able to run up to 64 axis and well over 1000 discrete I/O.

The MP-930 is very similar but has a few different ways of looking at the modules, but basically programs the same way.

The communication network used to talk to the axis is as easy as profi-bus or devicenet type interface. HMI's can be drop on the network and directly change axis movement in scan based real time.

I prefer A/B as a PLC but really don't care much for thier motion.

Hope this helped.
 
M

Michael Jackola PE

Mr. Bill Sturm,

I would like to introduce you to Delta's RMC100 series of motion controllers. We design and manufacture high-performance hydraulic motion control and servo motion control systems, along with extensive machine design and industry expertise.

Our motion control products are designed for easy programming and optimization and fast, precise, reliable performance. Our motion controllers support the most popular open-fieldbus architectures such as Ethernet, Profibus, Modbus Plus and Serial. Our motion control products also support a variety of feedback devices including Magnetostrictive linear displacement transducers, LVDT's, rotary absolute and incremental encoders, pressure transducers and load cells. These devices are available with many different types of interfaces. For example, analog, start/stop, pwm, quadrature, serial synchronous (SSI) and several others.

For a general overview of the RMC100 series motion controller refer to the following location on our web site:
http://www.deltacompsys.com/prods/motion/field/

The software, which is called RMCWin, can be downloaded at the following link:
http://www.deltacompsys.com/Files/rmcwinse.exe

The data sheets for the RMC100 can be downloaded in a PDF format at:
http://www.deltacompsys.com/dloads/#RMCDataSheets
Hopefully this will give you a good introduction to what we are all about.

Last of all, if you are interested in a phone/internet software demo, or need technical or application support, we can be contacted at the phone number listed below.

The Delta regional sales manager for your area is Rick Meyerhoefer.

We will send our complete catalog on the RMC product line by mail today.

Regards,

Michael Jackola,
Regional Sales Manager

Delta Computer Systems, Inc.
11719 NE 95th Street, Suite D
Vancouver, WA 98682
360-254-8688
Fax: 360-254-5435
[email protected]
 
J

James Ingraham

<clip>
> Are most PLC based motion using ladder based
> function blocks to program motion, or is the
> two programs with handshaking still predominate?
<clip>

I don't know about "most". ControlLogix does it right in the ladder. It's pretty clean.

<clip>
> There is the classic problem of combining a
> continuous scanning ladder process with a
> seqential motion program. Has this been solved
> by IEC-1131 and multiple languages?
<clip>

SFC is one way to deal with this. Still, I asked this question of A-B about 4 years ago when we started doing motion on ControlLogix before it had SFC support. They sent me a nice little example app that showed how to create "state-logic" in standard ladder. We've used the same technique on Siemens and Modicon, and I've seen plenty of other people do the same thing.

I'm afraid nobody can give you a particularly good recommendation. You just have to pick which demons you want to fight with. For us, the ControlLogix demons have been livable, Siemens's haven't been. Others will have the exact opposite experience.

Sincerely,
James Ingraham
Sage Automation, Inc.
 
D

Davis Gentry

I won't comment on the coordinated motion capabilities
of the various PLC manufacturers. I will however note
that our products are often integrated with PLC
systems, usually through a fieldbus such as Devicenet,
Profibus, or DataHighway. We also have a VME based
system which I have used in a number of cases with GE
90-70 PLCs.

Davis Gentry
Delta Tau Data Systems
[email protected]
 
M
Delta Tau used to have (still has?) a version of their PMAC for the GE 90 plc. Its been years since I used their stuff, but it works well, very well. Highly recommended.
 
Hello Bill,

I'm looking at almost the same exact thing in my evaluations of PLCs. We are about to try something new in my company, and I'm trying to pick the best offering for our application.

I agree with you on wanting direct integration into the PLC sequence code. I am also putting a stipulation to go with an IEC language offering because I value the things it offers in proper data typing and such.

You've left out a major player that has very good integrated motion, that is Mitsubishi. Their Q series controller has higher end Motion CPUs (For camming and electronic gearing and all that coordinated stuff) and they also offer basic motion units (They call then SSCNET positioner cards - basically for non-coordinated motion) that both snap right into the rack. The nice thing is that their amplifiers integrate over a high speed bus (SSCNET), so you have an inexpensive 1/2/4 axis positioner card with a cable to click into it to daisy chain to your drives. You can have as many of these simpler motion cards as you have expansion slots, and as far as I know the loops get closed on the drive, so you don't have a network bandwith problem with the motion bus. I even believe the "simple" card can do linear and circular interpolation on multi-axis, so it depends on your app as to what card you buy. You use software commands to move the motor right in the sequence, but I think you might be able to have a seperate program as well. Their motor offerings are nice and very comprehensive, and the controller/drive/motor combination is inexpensive. One thing I like about them alot is that their drive is small (About the size of a yaskawa sigma II drive) and there is essentially NO WIRING AT ALL. Absolute encoders come along for free, just add a battery to the amplifier if you desire. I am looking at using their IEC Developer software instead of the GX Developer because it adheres to the IEC philosophy better, although GX Developer has rudimentary IEC like features. As far as I know, IEC Developer is the premier package being actively used and developed in Europe, and the US is starting to catch on to it. The only reason I mention it is that your distributor will give you GX Developer if you don't request IEC Developer if you care about that kind of thing.

As I have said though, I haven't started using this system yet. I've been evaluating PLCs for months now (In between my regular work of course). Of your list, AB was the only one that seemed to have something close to mitsubishi, but their stuff was (alot) bigger and clunkier and more expensive than Mitsubishi. I think I priced the basic motion card and it was between $600-$800 depending on the number of Axes, and the amp-motor combos were decent, plus you can get their low end CPU and rack (CPU00J with PS and 5 slot rack) for something like $600 and it does a 200ns boolean instruction scan. With AB, you are looking at a real lot of money just for the base controller and rack to use on the ControlLogix platform (They don't have motion for CompactLogix yet...). Its worth having a local rep come in with a Demo.

BTW, I read my reply, and no, I don't work for Mitsubishi. :eek:) Their motion is just really well done from what I've seen. I'm looking to use the PLC for machine sequence, and use the SSCNET card for our general purpose positioning needs. When we have an oddball motion application, I was planning on buying a specific drive with integrated controller for that purpose, For instance on an extreme accuracy direct drive rotary turntable with single digit Arc/Sec accuracy using a Analog SinCos high resolution encoder, I was going to use an integrated controller and drive from KollMorgen (Their nice, check them out!) and just handshake it with IO signals the old fashioned way.

With siemens, I didn't see anythign of value in their offerings as far as small well integrated motion that was scalable, inexpensive, and high performance. They have a few options for backplane operation on S7-300/400 but I didn't like them for different reasons. I thought of possibly using Profibus with third party drives (like KollMorgen), but its potentially more of a pain.

I wasn't too impressed with GE. It was almost like totally seperate motion controller plugged into the bus, but only under one parent software environment. It was like a step above a third party motion controller, that seems a bit harsh, but I got that feeling after seeing how AB and Mitsubishi did it from a clean slate.

Keep in touch, I would value your opinions on this topic. Do you guys do sequential control with digital IO as well as motion, probably have a lot of handshaking between the two? I would think so if you want motion in the PLC.

~Ken
 
J
This post is in response to William Sturm's request for an integrated logic/motion controller that is accepted by Fortune 500 companies.

First I must introduce myself as the Eastern Regional Sales Manager for G&L Motion Control. I am doing this so that I am up-front with my affiliation. Prior to working for G&L I owned my an integration company for 25 years
specializing in motion control.

The integrated motion/logic platform you describe has been in use by G&L for over 20 years. The functions you describe, i.e. master/slave, cams, multi-axis interpolation, parametric motion, etc. are just a few of the hundreds of motion related functions available in the G&L library. The fact that the language is "old" doesn't mean it carries excess baggage, but that it is bullet proof. Furthermore, if you use G&L drives, the tuning software and oscilloscope functions for setting up and tuning the servo drives are built into the same programming software. It doesn't get more closely coupled than this. To top it off, they sell the software package for less than $300.

Now we come to the question regarding acceptance by Fortune 500 companies. G&L gets its roots from the old Giddings and Lewis Machine Tool Company. The name has changed a few times over the years, but it is still in the same location it was in when I started working with them 25 years ago in Fond du Lac, Wisconsin. Their MMC (Machine and Motion Control) products are found in machines operating in Fortune 500 companies throughout the world. However since it is not one of the "brand names", its acceptance is based on the fact that it outperforms the competition, not because of its parentage. Try logging on to http://www.GLcontrols.com, and do yourself a favor and have the local rep give you a demo before you decide against. If you are on the east coast, I will be happy to do it personally.

Joe Rizzolo
 
C

Curt Wuollet

As important as the product, is that expertise applying the product be readily available. As many of these built-ins are supplied in "black box" fashion, you need access to someone with knowledge of the internals when things get sticky. Most failures can be attributed to incomplete information.

Regards

cww
 
This is our observation no matter what the system is used for.

You can streamline into one PC with one application, using advanced software and IEC programming. This is the simplest and most reliable approach.

Paul Jager
www.automationX.ca
 
Hello,

Another good PLC / Motion platform might be B&R. http://www.br-automation.com They offer some really high end motion, and integrated HMI/IO/Motion programming. For instance, their drives offer 4096 SinCos Interpolation as a standard feature. They are currently on my evaluation list for controllers.

~Ken
 
Bill,

I understand what you mean by having a PLC system with decent motion integration by a well recognized manufacturer. I have fought this same battle for years. I read the other replies to your posting and agree with most. One system that you mentioned was Siemens Simotion D and you said you hadn't heard much about it. Siemens is just launching this product in the USA and has taken a very conservative approach as they build their support infrastructure. Simotion D is one variation of the control, there are 3. The C230 (Simotion C) is a rack based system which looks exactly like one of Siemens' S7-300 PLCs. The P350 (Simotion P) is the PC based version and Simotion D is a drive based controller. All of these products program with the same programming software, SCOUT. I am just getting rolling with this product but from what I can tell so far it is very capable and fairly user friendly. It can handle camming (excellent cam tools) & gearing, PLS functionality, absolute & incremental moves. Any axis can be a master or slave. Supports Virtual masters. It uses Profibus MC for the drive to motion controller interface and uses all of the Siemens standard I/O and HMIs. The programming environment is pretty rich (Ladder, MCC (Motion Control Chart) and Structured Text). If you haven't seen it yet contact your local Siemens Office and request that someone give you a demo.
 
I've faced similar issues with motion control in the past. About 10 years ago, I would have said that Giddings & Lewis Pic 900 is the only choice for a combination PLC and motion controller. G&L is still about the best that I've seen out there. However Allen-Bradley has done a good job with their ControlLogix architecture. The big advantage with using the A-B ControlLogix system is the number of networks that it communicates with.

From a pure cost/axis stance, plus inter-operability with many drives, Giddings & Lewis Pic900 is the best. But if you need a system with world-wide, around the clock support, then A-B ControlLogix is the way to go.
 
J
I agree with everything you said until you gave your reason for why you would chose AB over G&L. I believe that the most important issue where Global Support is concerned is how fast a company can respond, and how long it takes to get your machine/process back on line. My experience is that even though G&L may not have a distributor on every corner of the globe their responsiveness and ability to "fix" the problem is second to none. By copying G&L's architecture in the ControlLogix platform, I believe AB has validated the fact that G&L is the leader in motion control.
 
D
Ok - as an engineer working for Delta Tau I have left this one alone, but I can't see G&L called the leader in motion control. G&L and AB are both good at lower end applications. Try to get multi-axis coordinated motion, even simple motion (cut a fast, highly accurate circle, for example), and you run into issues. Even pick and place at high speeds can be problematic, in my experience. If I have a conveyor line that I have to interface with lots of slow i/o then AB or G&L is an excellent choice. If I am running 5 axes of coordinated motion then they are not even in the selection set.

But I will say that the proliferation of AB service is
very nice.

Davis Gentry
Delta Tau Data Systems
 
J
Unfortunately we could argue this until the cows come home. I have worked with G&L for over 25 years now and they have had easy to apply coordinated motion for as long as I can remember. In fact, because of G&L's machine tool
background, they can accomplish things like 3rd axis departure with ease. I didn't mean to do start an argument about whose Dad could beat up the other guy's Dad, I just thought that G&L was a nice fit based on the orignal criteria, and is worth consideration.
 
Well it's nice to see that all the manufacturers like and believe in their own product but I wonder if an unbiased engineer would say the same thing? What happens to these systems when you have to manage 12 axes? 30? 50? 200+? I think a real test of a motion control and how it can handle a single axis is whether or not it can handle many multiples of axes.

These systems do exist but you never hear about them because the users are happy to get the job done rather than being the mouth of the control systems vendors. Think about it.

If you actually take the time to look around you might find there is in fact a better mouse trap out there, it's simply a matter that you are not the one using it.
 
D
Actually, we have systems in the field with over a hundred axes. We are also used in a number of high precision one and two axis systems due to the very high capabilities of our controllers.

Note, however, that I did not say ours is the best controller. I merely said that G&L cannot be accurately described as the leader in motion control. I have not personally encountered any controller which is more capable than ours, but I have seen systems where other controllers might be a better choice. I have also gone into user sites on two occasions in the last year and in one week or less got machines running using our controllers after replacing controllers from two different highly respected controls companies. In both cases the machines were far behind schedule and had not shipped because the controllers originally purchased could not do what the sales guys said they could.

Davis Gentry
Delta Tau
 
J
I promised myself I would not respond to this topic again, but Davis Gentry makes some very valid points. I think what made me speak on this topic originally was that companies like G&L and Delta Tau are often not considered to be as big a leader in motion control as Rockwell, mostly because everyone has this impression that Rockwell's size makes them more able to provide world wide support. I think manufacturer's are doing their customers a disservice when they try to "force" a product to do every application because of reasons other than performance. The bottom line is some products are just better for certain applications.
 
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