Any good tutorial for beginner with Beckhoff/TwinCAT/EtherCAT experiences?

I am new to linuxCNC, but I have experiences in Beckhoff/TwinCAT/EtherCAT.

I am still confused on linuxCNC principles, especially:
* (I just installed linuxCNC, IgH EtherCAT master， RT-Preempt on Raspberry-PI.)
* How can we integrate an EtherCAT master to linuxCNC?
* How to setup to control/monitor Beckhoff digital inputs/outputs in linuxCNC?

Are there any good tutorials? Thanks!

Jerry

Thanks! I have found the EtherCAT driver for linuxCNC here:
github.com/sittner/linuxcnc-ethercat

Unfortunately, there is no instruction on building the driver.
Anybody knows how to build it? (I am new to Linux also.)