Servo drives, single axis motion

[swhite65]

When using the DSAPro, the dropdown menus for the drives and motors will be as G&L calls them. It is very easy to figure out the A-B equivalents. Playing around with this software offline will also show you how simple it is to set up offline. When you fire it up, it will scan for drives that are online. Just hit the "stop scanning" button to proceed with setting up an example file. Choose a drive and motor from the dropdown menus and go from there.

 

[Gerry]

Thanks for the feedback guys


The total cycle time is 12sec, this is with 5 feeds, 4 cuts the sizes range from 12" to 24" on the feed, with a tolerance of +/- 0.015 of a inch, this would include a trim cut, front and back


I was asked to use AB


Thats the positioning card, it needs to go, one of the issues with the older stuff its no longer supported.


I thought of that, but most of the people involved are asking for a PLC controled, so they can service it themselves, we did one with a Baldor (smartmove), but none of the tech could work on it, its getting back into the samething that were in now.



I guess I will look into modifying the speed reducer to fit the AB motor.

The brake on the system now only comes on, well after the autocycle has completed its last motion of the autocycle(aprox 3sec). I have removed the coil on one before and it work fine so I'm not sure of the reasoning for the brake, but it works fine without.

I will be doing this on 12 machines in the US, It would probably be the best keeping them all the same, from the motor back, since the majority of the motors are not the same and it would be a lot of leg work researching the compatibility

thanks again

I recommend that you avoid all the el-cheapo suggestions that have been offered - they will cost you time and future headaches. Your customers' in-house techs will curse you for the complex ladder required to manipulate the data and the inability to even monitor the program since the serial ports are in use.

With the L43 CompactLogix, I believe the only motion control option is sercos. This puts all drive and axis configuration in the PLC and all motion control programming into the ladder. I can't remember whether the L43 has ethernet built in or requires an adapter, but, either way, you should have it. Use enet for the PV+ connection and you will have one connection to make for on-line editing/monitoring of the PLC and for making changes to the PV+.

People always want to make modifications/enhancements over time and the L43 system will make it easy. The micro system will be perceived as a closed 'black box' system that is difficult if not impossible to maintain - never mind modify.

As for the brake - servo motor brakes are holding brakes, not service brakes. They are intended to prevent axis motion when power is off. They are generally only necessary if the axis is affected by gravity.

 

[Alan Case]

Another option is the L3X version of the Compactlogix instead of the L4x, plug in a devicenet module and use the ultradrive controlled via Dnet.
Regards Alan Case

 

[Gerry]

Another option is the L3X version of the Compactlogix instead of the L4x, plug in a devicenet module and use the ultradrive controlled via Dnet.
Regards Alan Case

Controlling the indexing drives over devicenet is long-winded and non-trivial. For a system requiring operator-selected variable cut lengths, programming effort would be significant.

 

[swhite65]

I don't know your specifics but I added a servo motor to a similar setup a while back, and I was able to do it without the PLC. This also saved cost. The feed and cut operations were seperate and each activated by push buttons. The feed was controlled by a small HMI connected to an indexing drive. Just an idea.

Gerry: Your more recent post seems to contradict this one. I don't understand the switch.

Automation Tech: When the "other people" involved say they prefer the motion control to be done with a PLC, what are they referencing? What other setups do they maintain that produce this request? You also state the replacement components initially; is this basically following your A-B guy's suggestion? You can certainly do this with A-B, but with a much less expensive arrangement. Suggesting SERCOS raises a red flag and the cost.

Also, with the indexing drive the ladder logic in the PLC will be primitive as you are merely turning on discrete outputs to execute the feed. The protocols are handled by the devices so you are not doing anything but manipulating variables (bits and integers). Oh, by the way, do you already have RSLogix5000? You'll need that too for the Compactlogix.

Now, if you are going to keep the existing motors, you have narrowed your options somewhat. You can't just hook that Ultra drive up to that motor.

 

[Peter Nachtwey]

Interesting.

I don't see why this application should be a problem. I don't see what a PLC adds to the application. I would think this application can be done with a HMI , smart drive and the servo motor. If not then an HMI, a smart motion controller, dumb drive and servo motor.

 

[OkiePC]

I think the decision whether to have a PLC and/or HMI all depends on how often changes are made to the index position, and how many different cycle sequences there are. Another factor will be how many input and output device are involved and what type of diagnostics might be most useful.

I would want a PLC if the sequence changes very often, there are more than a handful of I/O, and an HMI if the index settings are changed very frequently. I would not want to rely on a drive programming software and laptop for common adjustments, but that might be just fine if it only happens once a week.

JMHO

 

[swhite65]

Very good points. One advantage to the Ultra drive software is that there are no lines of code whatsoever. It is purely "fill in the blanks" in the setup of the operation so manipulating move distances or other parameters is done by changing the corresponding variables in your PLC and/or HMI. So once this drive is setup, it should not have to be accessed with a PC again.

 

[swhite65]

If anyone is in need of any SERCOS drives, there are a couple of the G&L versions of the Ultra drive on eBay. One is $300 and the other is $500. The current ratings are listed for each drive. These are the "Buy it Now" prices which is very cheap.


http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160071648160&ssPageName=ADME:B:WNASIF:US:76&refitem=&itemcount=0&refwidgetloc=&refwidgettype=osi_widget&isfrommerc=1

 

[kamenges]

Originally posted by OkiePC:

I would want a PLC if the sequence changes very often, there are more than a handful of I/O, and an HMI if the index settings are changed very frequently. I would not want to rely on a drive programming software and laptop for common adjustments, but that might be just fine if it only happens once a week.

Originally posted by swhite65:

Very good points. One advantage to the Ultra drive software is that there are no lines of code whatsoever. It is purely "fill in the blanks" in the setup of the operation so manipulating move distances or other parameters is done by changing the corresponding variables in your PLC and/or HMI. So once this drive is setup, it should not have to be accessed with a PC again.

I don't agree with this. I haven't have a chance to work with the Delta Computer RMC series (one day, Peter, one day). But the Rexroth Indradrive with the integrated Motion Logic would do both logic and motion very easily. I look at the whole 'fill in the blanks' thing as handcuffs. You are locked into the design philosophy that the designer of the 'blanks' believes is the correct philosophy. It's one of the real beefs I had with the Rexroth Synax product before they integrated Motion Logic into that. Just because a specific product CAN'T reasonably handle logic development doesn't mean that logic development on a motion platform is a universally bad idea.

Keith

 

[Peter Nachtwey]

But the Rexroth Indradrive with the integrated Motion Logic would do both logic and motion very easily.

From the description this application would be easy. Here is a harder one.

ftp://ftp.deltacompsys.com/public/movies/Auto Lay Up.wmv

All the sequencing is done by the motion controller. The step table ( program ) would fit on one screen. This was done by our second generation product. The third generation product can blow the socks off most PLCs and still have time for motion and communications.

I just don't see the need for the PLC. That is overkill for just a little sequencing.

I look at the whole 'fill in the blanks' thing as handcuffs.

Yes, but they were probably necessary then. Now motion controllers have much more processing power so that some of the restrictions can be removed. You must remember that the motion controller must do a little motion control between the sequencingng and the communications. One can't let the user programs use all the time with infinite loops etc.

 

[hounddog]

Thanks to everyone

could someone post some example programs etc.

along with the suggestions as to what to use.

Thanks

 

[Gerry]

Here is a harder one.

ftp://ftp.deltacompsys.com/public/movies/Auto%20Lay%20Up.wmv

Lay up has changed a lot since my days at M&B Vanply in the 60's.
They designed and built a couple of auto lay-up machines there - one of my first control systems.

There seemed to be a lot of glue-covered sheets between face sheets - what are they making?

Back on topic:

Automation-tech was the one that decided he wanted a PLC, so let's assume that he has valid reasons. He hasn't told us what he's cutting, how whatever it is gets to the index & cut gizmo, how it is taken away after cutting, or what happens to the trim. There's likely some advantage to having the control of associated equipment consolidated - for him and his clients. It's also likely that his clients - apparently spread far and wide around the US - are comfortable with PLC's.

If anyone is in need of any SERCOS drives, there are a couple of the G&L versions of the Ultra drive on eBay.

Is Brand X sercos compatible with Brand Y sercos?
I realise G&L badge the Ultra drives, but in the past, they have had their own firmware. The BRU drives made by the Electrocraft division of Reliance, re-named Ultra 100 & 200 when taken over by AB/Rockwell, had different firmware from the G&L equals. Seems probable to me that a G&L badged Ultra 3000 will have differences as well.

 

[Peter Nachtwey]

There seemed to be a lot of glue-covered sheets between face sheets - what are they making?

The glued sheets are the inner sheets of a wooden 'billet' that is 30 to 50 feet long and about 4 inches thick. This allows one to make big ones out of small ones. The big wooden billets can be cut into 4x12s of lengths that are hard to find now days.

If you look carefully you can see the billet move beneath the gates. The billets move slowly and were controlled by the PLC5. The press itself is out of view. The PLC5 also controlled the gluing machine upstream.

What may not be noticeable is the two photo cells that detect the skew of the sheets. The controller must re phase the belts on-the-fly so the sheets line up with the laser line. The photocell were connected to the home inputs so the positions are latched at the micro seconds level to minimize the phasing errors. The integrator went through a few photocells to find some that are fast enough.

The lay up machine was made by Raute Wood. This is a Finnish company that has a branch in Vancouver BC.

 

[hounddog]

program examples or actual item used and means of connection etc., would be more useful.