AB Servo capabilities

Hi All

I am planning my first servo project - nothing too fancy, just an assembly machine with 3 linear axes and one rotary axis. The fussiest tolerance is +/- .005 repeatability over 12" of travel. I was hoping to use the CompactLogix platform since I know the software. A system integrator who uses only Indramat told me that the AB equipment is mostly useless when it comes to motion control. I find this hard to believe. Does anyone know of any examples that would help me convince my boss that I am not travelling down the wrong path?

The Indramat user is a little out of date...in fact I would say that AB could control an Indramat drive over SERCOS, but an AB 2098 SERCOS drive should work excellent with the Compactlogix

BUT how about giving some details on what you need to do before we say for sure

Do any of your axes require coordination (electronic gearing)?

I will be stitching around the outside bottom edge of a 4' cube with rounded corners - like an odd shaped mattress. I will be pulling a platen (from the center) in a straight line through the sewing machine. When it gets near the corner (3" radius), I will be firing a shot pin at the radius center then reversing the direction of the platen which will swing it 90 deg. while the rounded edge is being sewed. Once the 90 deg. turn is complete, the shot pin will be released and the direction reversed again so that the next long edge is being pulled through and stitched. The sewing head has to tilt 45 deg. while doing the corners and I may have to control the distance between the wall of the cube and the sewing head. (ultrasonic distance transducer?)

The sewing machine spindle speed will also need to be controlled with a foot pedal and coordinated with the platen speed.

Right now all of this is still in the arm-waving stage

So, (i think) the answer is yes, there is a lot of coordination between the axes.

In that case, you should consider using ControlLogix based motion.

OkiePC said:

So, (i think) the answer is yes, there is a lot of coordination between the axes.

In that case, you should consider using ControlLogix based motion.

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I 2nd that.

Go with Kinetix series 6000 but if you don't require a lot of Kwatts the 2000 series is out.
I've been asking for it, but the local rep hasn't gotten back to me.
All motion and machine controls will be done in the PLC. Since you only have 4 axes, a CompactLogix L43 will be all you need. (still need the sercos module and the ENBT for Ethernet IP).
I also think that the tolerance is tight and your hardware (couplers, etc and not just the servos will have to be looked at closely).
Anything with up to 4 axes that I have done in the last 2 years or so I used the L43. No issues so far.

TWControls said:

The Indramat user is a little out of date...in fact I would say that AB could control an Indramat drive over SERCOS

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Out of date?? Where have you been?
The Indralogic software based on the CoDeSys programming system developed in conjunction with 3S far surpasses ControLogix especially for motion applications. The Bosch MLC [Motion Logic Controller] is very powerful even for conventional "ladder" applications.
It would be equally capable of controlling AB Servo Drives if Rockwell didn't make it a point to deliberately NOT follow standard Sercos drive parameters to make them "easier" to use with ControLogix. "SoClose" vs. "Sercos" has been a term floating around for a number of years from users frustrated when trying to use AB Servo drives on other platforms.

As well as Bosch you may also want to take a look at B & R Automation. They also have a wide range of products for motion applications. Their software is also CoDeSys based.

BITS N BYTES said:

Out of date?? Where have you been?
The Indralogic software based on the CoDeSys programming system developed in conjunction with 3S far surpasses ControLogix especially for motion applications. The Bosch MLC [Motion Logic Controller] is very powerful even for conventional "ladder" applications.
It would be equally capable of controlling AB Servo Drives if Rockwell didn't make it a point to deliberately NOT follow standard Sercos drive parameters to make them "easier" to use with ControLogix. "SoClose" vs. "Sercos" has been a term floating around for a number of years from users frustrated when trying to use AB Servo drives on other platforms.

As well as Bosch you may also want to take a look at B & R Automation. They also have a wide range of products for motion applications. Their software is also CoDeSys based.

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BNB, you should learn how to READ the entire thread instead of bits and bites like you name suggest before you jump too conclusions

Where in my reply did I say that anything was superior to anything.

I was hoping to use the CompactLogix platform since I know the software. A system integrator who uses only Indramat told me that the AB equipment is mostly useless when it comes to motion control

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My reply simple clarifies the point that AB's equipment is capable of motion control. Something that his integrator gave him false information on. I never suggest it is superior...in fact I'm working with some Indramat equipment right now and am extremely pleased with its performance...but that's not what Norm ask. He asked if the Compactlogix was capable of it. I told him it was and asked for further details on his project.

Remember - Read, THINK, and then post.

TWControls said:

BNB, you should learn how to READ the entire thread instead of bits and bites like you name suggest before you jump too conclusions

Where in my reply did I say that anything was superior to anything.

My reply simple clarifies the point that AB's equipment is capable of motion control. Something that his integrator gave him false information on. I never suggest it is superior...in fact I'm working with some Indramat equipment right now and am extremely pleased with its performance...but that's not what Norm ask. He asked if the Compactlogix was capable of it. I told him it was and asked for further details on his project.

Remember - Read, THINK, and then post.

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Excellent point...

I think that my confusion about motion control capability is entirely based on inexperience and I plan to fix this shortly. The reason I originally asked for examples is for "show and tell". If the big players are using AB servo systems in critical applications, then there is no reason why this can't be used for our modest projects. But I'm beginning to think that there is a break point (number of axes?) where only a more sophisticated system will do the job.

I wouldn't say it is number of axis, since you could just move to the Controllogix to get more. It has more to do with the complexity of motion.

Are all axis independant? Are they simple linear moves? Do you need to do any circular interpolation?

TWControls said:

I wouldn't say it is number of axis, since you could just move to the Controllogix to get more. It has more to do with the complexity of motion.

Are all axis independant? Are they simple linear moves? Do you need to do any circular interpolation?

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Hi Tim,

This is exactly my point. I guess I made the assumption that all major platforms had pretty much the same capabilities in terms of integration and complex motion control. Did you find Indramat (Bosch-Rexroth) programming software fairly intuitive?

Disclaimer - This is my opinion, no where in this post am I saying that on product is superior to another...

Personally if I had to spec a motion controller, were more geared towards PLC programming, and were not familiar with any particular brand, I would look into Delta Computer Systems RMC controller
http://deltamotion.com

I evaluated Delta and was very impressed. Never mind capabilities and spec sheets. Looking at it from a maintenance point of view it was great. It has extensive diagnostics in the software, trending, etc

But what I really liked about the RMC was its capability to interface with a variety of PLCs. So your familiar with PLC programming, use it for your logic and the RMC strictly for the motion. Maintenance really likes these setups, the servo system is rarely the problem and they are familiar with ladder. They can do 95% of the troubleshooting and don't have to learn the motion software.

Delta support...if you have a problem, you've got one of the best motion guys in the industry to help you out.

Unfortunately I don't get to spec parts much anymore. I usually come in on the tail end of the projects when they are not working correctly. I have seen some Delta's in service but they have never missed a beat, so I guess I'm like the Maytag man waiting on them to break so I can get a closer look at them.

Sounds like you need 3 axis of coordinated motion. Can't do coordinated motion with with a compact logix. You need to use a control logix. more $$$$
What is your 4th axis?
Is it an orientation axis?
If so you will need a 4th axis of coordinated motion for the path planner. In that case you need something from a different manufacturer (since is only does 3 axis kinematics)...
More than a couple of simple axis on a compact logix will bring it to its knees, and ethernet comms for programming will slow down etc.

If the obvious solution won't work I have an alternative that will

hokie said:

Sounds like you need 3 axis of coordinated motion. Can't do coordinated motion with with a compact logix. You need to use a control logix.

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Yes, he can. Just connect the CompactLogix to a RMC150 over Ethernet. Mounting the RMC in Jbox by the machine will reduce wiring too. The RMC shows up as a node on RSLinx.

If so you will need a 4th axis of coordinated motion for the path planner. In that case you need something from a different manufacturer (since is only does 3 axis kinematics)...

Click to expand...

More than a couple of simple axis on a compact logix will bring it to its knees, and ethernet comms for programming will slow down etc.

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Again this is not a problem. The RMC off loads the PLC and does all necessary coordination, PLC just needs to download parameters if necesary, tell the motion conroller when to start/stop and monitor its progress over Ethernet. Even a ML1100 work nicely.