Yaskawa servo options

Hi,

I am working on building a cnc router and I currently have the ability to get yaskawa servos and drives for a very reduced price.
Is it possible to control Yaskawa drives with linuxCNC? The available communication protocols are mechatrolink, ethercat, and analog/pulse.

Any help is greatly appreciated. I'm really new to this all!

S

Steejans wrote: Hi,

I am working on building a cnc router and I currently have the ability to get yaskawa servos and drives for a very reduced price.
Is it possible to control Yaskawa drives with linuxCNC? The available communication protocols are mechatrolink, ethercat, and analog/pulse.

Any help is greatly appreciated. I'm really new to this all!

Those are great servo/drives. I use them all the time with Linuxcnc. Definitely analog/pulse models. SGDB

What do you use to control the drives? Do you have any specific recommendations?

I am having trouble figuring out how the analog/pulse models actually work lol

Just make sure you don't get Machatrolink drives. They're essentially impossible to control. It's easy to think that all the SGDB (if that's what ou've got access too) drives are the same but model designation is very important. I've got 4 mechatrolink drives on the shelf for that very reason.
I'd imagine EtherCat would be a great option too but +/-10v analogue is easy. Messa 5i25/7i77 is one common hardware config that will give you control over analogue drives.

Steejans wrote: What do you use to control the drives? Do you have any specific recommendations?

I am having trouble figuring out how the analog/pulse models actually work lol

SPH is correct. SGDB drives are great but they come in different flavors. Make sure you get analog/pulse.

7i92/7i77 for analog or 7i92/7i76 for step and direction.

Those are my pics. Of course there are other options but I am biased to things I know works and don't have to reinvent anything.

Are analog pulse or step/direction better?

The options are analogue OR pulse (== step direction)

Both work well, there really isn't much to choose between them.

EtherCAT is very nice too. I have Omron G5 EtherCAT drives running under LinuxCNC.

Pros:
* Very simple cabling - just plug in a CAT5/6/7 cable.
* Galvanic isolation between computer and drives.
* My EtherCAT drives have generic IO:s, so no further IO board needed. This includes functions to latch encoder position on rising edge, for tool height setting and edge finding.
* All loops closed in the drives, and you can feed-forward velocity and acceleration as well as the position reference to the drives.
* Possible to read back multiple values (besides encoder position), like control effort.

Cons:
* Lots of manual reading to do to set up things the correct way, especially if you need to use the generic LinuxCNC driver. You pretty much need to become an expert on the EtherCAT protocol - it can get pretty frustrating. Make sure to find and read the manual for the drive first, before you buy, so you know what's in store. You *will* need to read up on PDO mappings and such. (As far as I know there is no special driver for Yaskawa EtherCAT drives in the etherlab package for LinuxCNC, but if you are a programmer you should be able to modify the Omron G5 one which would probably be easier than using the generic driver.)

I would absolutely go for EtherCAT if I had the choice!

You would really suggest ethercat to someone that is so new he is asking about the difference between analog, pulse and step and dir?

No, I cannot choose for him/her. But I can point to EtherCAT as a possibility so he/she can make an informed choice. That's why I also explained the cons in my post and pointed out reading the manual before taking this path.

Besides, with EtherCAT you don't need to know the difference between analog and step/dir. Steejans will have a lot of reading to do regardless of choice.

One thing that maybe I should have made more clear is that with EtherCAT, you will not find nearly as much help on the forums, since analog and step/dir is much more common. So again, read the manuals, forum etc and make sure that you're comfortable with taking that route before buying anything. That said, I had no knowledge of EtherCAT before, and managed to read up on it (using the Servo Drive manual and this forum) and get it working on my own, so it IS possible.