openPOWERLINK is an Open Source Industrial Ethernet stack for communication in hard real-time. It can be operated as both, Managing Node (master) and Controlled Node (slave).
With version 2.0, the source code has been cleanly split into an application-oriented user library and a time-critical stack driver. The latter may be moved to a dedicated communication processor or into a kernel module to deliver enhanced performance while still keeping the API in user space.
A full documentation...