Re: [CAD_CAM_EDM_DRO] EMC2 I/O Cards

Anders Wallin wrote:

>The idea with gecko or rutex servo drives is that the drive uses encoder
>feedback, the computer only outputs step/dir signals, so in a standard
>config EMC2 would not use encoder feedback with a gecko or rutex
>step/dir servodrive. However there's been some recent talk on the
>emc-list about using feedback with these step/dir drives.
>

I have a tested solution for using encoder feedback to the computer with
Gecko
drives. I call it my Gecko Interface, as it is more specifically wired
for the Gecko
320 servo drive. But, it could be adapted (pretty easily, I think) for
other step/dir
servo drives. It takes the encoder input directly, and makes an
opto-isolated copy
of these signals for the Gecko drive. It seems to "tighten up" the
servo response
of the Gecko drive quite a bit. It also allows you to graph the servo
response with
EMC, so you can actually KNOW what the following error is under various
conditions.
You can also set the following error limit as tight as you want, instead
of being
stuck with the Gecko's 128 count fixed setting.

It also switches power to the Gecko drives, so if something goes wrong,
it cuts power
and applies a braking resistor to all axes. It handles all the drive
resetting and
fault detection. This is designed to work with my Universal Stepper
Controller.

See http://jelinux.pico-systems.com/gecko.html

Jon