Have nobody any help for me? i am looking to implement ETHERCAT protocol on arduino. is there any possible reference about or libraries or direction manuals or anything out of wikipedia?? please do not say to me to use a external I2c interface chip : i cannot 
thanks
i am looking to implement ETHERCAT protocol on arduino.
Hey, look, it's link time. Oh, darn. No link.
please do not say to me to use a external I2c interface chip : i cannot
OK. I'll bite. Why not?
Sorry for delay
i cannot use i2c because i shoul like to know if it is possible to avoid hardware implemantation. my hope is to use thernet shield and implement ethercat on it . I am italian so i not understand well your answer . what does means "it is a link time" of previous message ?.
have you any idea about possible implementation of ethercat protocol?
thanks
have you any idea about possible implementation of ethercat protocol?
No, I don't. I don't even know what it is. That's why I posted the comment about a link. You need to post something that defines what ETHERCAT is, so we can see if it is reasonable to even consider using with/on an Arduino.
EtherCAT slave implementation guide: http://www.ethercat.org/pdf/english/ETG2200_V2i0i0_SlaveImplementationGuide.pdf
Source: EtherCAT Technology Group | Downloads
I would suggest becoming a member of the EtherCAT Technologies Group for more resources.
It would be a nice idea.
But regarding ethercat implementation, this would be a slave implementation needed for most applications.
In this case a special network chip needs to be wired to arduino, because of the fastforward switch feature needed between ports. (this implies wiring an ET1100 or ET1200 beckhoff asic)
This implementation would be very interesting for industrial applications.
This is an old post but you need 2 rj45 (ethernet cable ports) jacks to utilize ethercat
does your controller have two?