• Git Repository: https://gitlab.com/etherlab.org/ethercat
• Documentation: https://docs.etherlab.org/ethercat/1.6/pdf/ethercat_doc.pdf

EtherCAT is probably the most advanced industrial Ethernet bus.

Since it's specification is public to the members of the EtherCAT Technology Group, every one can implement an EtherCAT master.

IgH has done this with a C implementation for Linux, which allows to transfer process data to and from EtherCAT slaves.

It can be run as a realtime application or, if not critical, even without any realtime requirements at all.