Thread: Linear servo motor control

**mvalente3** · 08-26-2022, 01:10 AM

Hi all -

Long story short I came to own a XY gantry driven by permanent magnet linear motors - the motors & encoders are connected to servo drivers that are daisy chained with ethernet.

I'm looking to try and get these motors running but I am at a loss of how to figure out how to drive them because I don't have any information on the motor itself or servo driver. I'm familiar with typical rotary servo signals and connecting to a motion controller but I have not used any drives with an ethernet connection or linear motor before. I've reached out to the company that originally made the machine but I doubt they will get back to me or help me too much since I'm not the original customer. Any thoughts on how to go about this? Would love to give this machine a new life!

Cheers,
Michael

**joeavaerage** · 08-26-2022, 02:16 AM

Hi,
if you are familiar with rotary servos then linear servos are no great hurdle. The problem is that these servo drives are daisy chained together, possibly EtherCat or Profibus or similar bus communication
system.

You will have to identify what system is being used. Its common for EtherCat servo drives to be Ethercat ONLY, that is to say you cannot drive them with Step/Dir pulses as you may be familiar with.
In order to use them you would have to get an EtherCat master, a modified PC for example. In the case of EtherCat getting a master is not too much of a bother but Profibus is another matter, being
proprietary it could be expensive.

Craig

**mactec54** · 08-26-2022, 09:23 PM

Originally Posted by mvalente3

Hi all -

Long story short I came to own a XY gantry driven by permanent magnet linear motors - the motors & encoders are connected to servo drivers that are daisy chained with ethernet.

I'm looking to try and get these motors running but I am at a loss of how to figure out how to drive them because I don't have any information on the motor itself or servo driver. I'm familiar with typical rotary servo signals and connecting to a motion controller but I have not used any drives with an ethernet connection or linear motor before. I've reached out to the company that originally made the machine but I doubt they will get back to me or help me too much since I'm not the original customer. Any thoughts on how to go about this? Would love to give this machine a new life!

Cheers,
Michael

Do you have the servo drives, there must be a manufacturers name / part number on them, take some photos I have used a lot of linear motors and drives they come in many different ways to control them

**mvalente3** · 08-28-2022, 01:12 AM

I did some more disassembly and found a lot more information.

The linear motor is an I-Force made by Parker. I found some guides from people repurposing these or similar motors (https://sites.google.com/site/janbec...ter?authuser=0).

I took apart the servo drivers and it looks like they are from PMD (https://www.pmdcorp.com/?hsLang=en) - maybe an Ion / CME board. PMD mentions support for ethercat, so so maybe it is ethercat? They have a configuration wizard on there website, I might download that and see what happens.

In the meantime I bought a used Compax3 drive from Parker that should also work to try and drive it.

Thanks for the help - I'll post an update if I get it moving!