I am looking at a small application and trying to find a low cost PLC to do the job.

The system will have 2 axis control. There will also be general machine control done with a PLC (around 80 DI/DO and 1 AI), so an integrated system would be nice.

Motion is just a pick and place application and the PLC logic is a fairly simple batch process.

Appreciate your help.

 

Supposedly B&R has a well integrated logic and motion solution but I haven't used it. Beckhoff has similar options at least on paper. Delta Tau has a nice new total machine controller called the PowerPMAC. It might be harder to use at first but is very capable and programmable in their script languages or C with realtime multithreading if you need it.

What is your budget for motion, PLC, IO ,and HMI? Saying "cheap" is not helpful.

KEJR

 

2-axes Galil motion controller with extension up to 64 I/O or more can be option also. Programming such controller including motion and PLC task with two-letter, intuitive commands is simply.

 

There are a lot of systems that could do this task for you. Is this thing using steppers or servos? Some low end PLCs have pulse outputs for steppers built in.

80 some I/O is a bit past an entry level PLC, but not a whole lot.

I would stick with stuff you have some familiarity with, if it makes sense economically. The learning curve is expensive many times.

You may find that the most economical solution is not an integrated one.

Most of the time, an integrated solution, especially with a simple application like this, does not really gain you much.

I have had pretty good luck a couple times with some AB PowerFlex40P drives for simple motion control and a Micrologix 1100. That won't do 80 I/O but a 1400 will. And 1400's are available with 6 built in high speed counters. If you motion control needs are not real demanding it is possible the cheapest VFD you could find would work to run the axis back and forth.

A 1400 base unit has 32 I/O and analog inputs built in. At $600 or so, it is not real pricey for what you get.

If you prefer some other brands there are comparable units from every other PLC maker in the same class both feature wise and price wise.

If your motion control needs are more demanding and you prefer integrated motion, the Compactlogix platform has very nice motion, but not real cheap.

--
Bob

 

If you want to do it "cheap", look for a drive that has built in indexing and use Digital I/O for selection of index points and feedback of in position etc.

If you want to do it a little less cheap, use a drive with index capability and some sort of comms bus and communicate over the bus to command a specific index.

If you want to do it a little less cheap than that you can go to a motion controller with I/O capability or a PLC with motion capability. I personally like the motion controller with I/O myself. some people have already made suggestions on this option so I'll leave it at that.

 

Delta Tau has a number of controllers that could do this. The Clipper is an inexpensive 4-8 axis controller which can be ordered with ModbusTCP communications. Through modbus you can interface with fieldbus i/o (I like Wago) of any sort. The UMAC is a more expensive 2-256 axis rack mount system (above 30 axes you have to use additional racks with the MACRO fieldbus) with integrated i/o and also multiple fieldbus options. The UMAC can use the new PowerPMAC controller, or the older Turbo PMAC controller.

All of the above have native kinematics capabilities.

Feel free to contact me offline for more information at dgentry |a|t| deltatau |D|0|T|C|0|M

disclaimer - I am a Delta Tau apps engineer, so am partisan.

Davis Gentry

 

If you do not have a fair amount of PLC and motion experience, then you may well find that this "simple" request will be more difficult than you imagined.
(sighs... I wish it were not so, but it is)

Look for a vendor that has good support and has good examples of systems that you can fashion your system around. I do not know of an obvious solution right off, and I have been doing this for twenty years. What is good for me may not be good at all for you. Basically, a motion controller is good at motion and a PLC is good at logic, but the two do not come together all that easily. Some PLC's do motion and most motion controllers can do logic, but they are all compromised in some way or another. All too often, you discover these compromises at the worst possible time, like the night before you are planning to demo the system.

For a pick and place with fixed moves, your job is easier. I would suggest any PLC with a couple of drives with built in positioning capability. Use the PLC digital outputs to trigger the drives to move at the appropriate time. This has already been suggested and it is a tried and true method.

If you need moves to be flexible in speed and position, then I would suggest a PLC with integrated motion, or intelligent drives that can communicate with the PLC or an HMI to share data.

An HMI with two comm ports that can communicate with servo drives and also a PLC might be an excellent start. I would look at A-B or Automation Direct, but there are many others.

Bill Sturm

 

Off-hand I have trouble thinking of a modern PLC that CAN'T do this. True, "low cost" does restrict things a bit. As someone else mentioned, how "low cost" you need to go can color things.

Another factor here; you haven't mentioned anything about the motion beyond "2 axis." Do they need to be co-ordinated? i.e. do they need to follow an exact path, or can you tolerate some error in the path? What size are we talking about, at least in order of magnitude: oz-inches, in-lbs, ft-lbs. (Why is oz-inches always in reverse order compared to in-lbs and ft-lbs?) Are you planning on using servos, steppers, or less precise positioning say with standard AC motors on variable speed drives? How do you plan on communicating to the drives? Is there flexibility in the drives or has someone already spec'ed them out?

Regular readers of control.com are probably tired of hearing me say this, but location matters as well, at least by continent. The North American market is very different from Europe's.

For what it's worth, I would start with an Allen-Bradley CompactLogix, talking EtherNet/IP to Bosch Rexroth IndraDrive C (or Cs) servo drives with IndraDyn S (MSK) motors. Bosch Rexroth also has their own controllers, which could handle synchronization if you need. Conversely, A-B has their own servos, but I generally feel you will pay more for them.

Schneider Electric has been pitching their Modicon M and LMC PLCs to me lately as low cost. They can run Lexium servos over CANopen if you need synchronized motion, or Ethernet to lots of options otherwise. (Including a different version of the Lexium and the afore-mentioned Bosch Rexroth.)

Siemens has plenty of good solutions. An S7-300 with Profinet could run Siemens servos or Bosch Rexroth, although you have to stick with Siemens if you want the synchronization.

AutomationDirect.com has been mentioned. I haven't paid that much attention to their line, but they offer several levels of controllers as well as servos.

Beckhoff and B&R both offer a wide range of options.

Good luck.

-James Ingraham
Sage Automation, Inc.

 

Hi,

Have you looked into using a simple and economical CANopen HMI/PLC with integrated brushless motors? We just completed an App note on mating an economical Unitronics V130 series PLC/HMI with our integrated brushless CANopen integrated motors. The result is a really inexpensive single or multi-axis coordinated motion solution, far less expensive than Delta, Animatics or Siemens. The ladder logic on the Unitronics makes it very easy and simple. The Dunkermotoren motor can do point-to-point motion with a few CANopen commands.
We just posted the App Note at http://www.dunkermotoren.com/default.asp?id=112&lang=2

Please contact us for the ladder logic program (we still haven't posted it online) at [email protected]

Hope that helps.

 

I have an application using AB Compactlogix to a Bosch Indradrive C over EthernetIP, and have had difficulty finding any information regarding the comms setup and mapping. Bosch sent me to the local supplier for information and the local supplier has been unresponsive so far. It sounds like you have experience with both; do you know where I could get Bosch manuals for the fieldbus, and possibly AB sample projects?

 

from what I understand Indramat does not have an add on profile so you will need to set up a generic ethernet module... these videos pretty much show you exactly what you have to do:

http://www.motiontech.com/cms/products/rexroth/rexroth_app_note

 

Wow; great link. I could have used it about 3 years ago when I was setting this stuff up the first time. I hope that helps Mr. Deason out.

-James Ingraham
Sage Automation, Inc.