speed control for servo drive

[jcraft]

Hi all,

Bear with me because I am new to this control/automation stuff. We are building a spiral cutting machine in house and it presently has a Bosch-Rexroth Indramat servo drive with matched 3 phase servo motor. Right now for testing purposes, all we do is go in with a laptop via rs-232 and in the drivetop program for the drive we can punch in a speed value and were good to go. However, now they want to build controls permanent for this so an operator can run with it. Basically, all we will need to do is turn the motor on and dial in an rpm and then let it run. They want the cheapest setup they can get. Not sure how to control the speed on a servo motor. Is it like a vfd where we can control via a potentiometer and then link it to some sort of analog meter that shows rpm. Also , would we need to link through a plc or could they just interface directly with the drive. Ultimately we would probably want to send to a plc because there may be some other things we may need to turn on ( air solenoids) If any body has any thoughts on how to accomplish this let me know. I have limited experience so any info will help. Thanks

 

[PLClatin]

Dear Jcraft:

Perhaps your need could be as simple as to use a VFD, I think your application may involve more than that. As you indicated you already have a Cutting machine with servo drive. Using a VFD you may not get the right functionality for the cutting. So I would look for a servo drive + motor with plc and hmi. The right size of a servo depends on so many diferent things that is not advisable to choose one without enough experience. I may recommend to you a few options but probably this would not be right in this forum. Write me at fguedez at cantv.net and I will respond.

Regards

 

[avante]

Well you might want to consider a different kind of servo drive. Indramat drives are VERY expensive to repair and even harder to retrofit. The com software is another problem. Depending on how fast you are running, you might be able to use a flux vector drive.

 

[blacksea]

I hope that using macro programming you may change velocity reference with any trimmer connected to analog input. Check with Indramat such option. And if No, review "smart" single axis motion controller with build-in power amp from Elmo (

http://www.elmomc.com)

as example.

 

[jdbrandt77]

There are two direct interfaces to an Indramat drive to do what you want to do. 1) Indramat VCP, ... like a Maple Systems OIT, but much more expensive, and 2.) EXOR. Less expensive, and its better suited for what you want. You'll want to set up a write to an IDLE SPEED register, and off you go.