Target) and the user interaction related procedures (the Host) run independently, typically on two different CPUs, communicating over the network (Internet).
The RTAI-XML approach, presented in the second picture, follows this general phylosophy. The core of the system is the RTAI-XML server that works as a bridge between the HRT and the SRT domains, allowing to instantiate a procedure from the SRT internet network to the HRT RT_NET network. From the internet side, RTAI-XML implements an RPC server based on XML; inside the RTAI domain, RTAI-XML connects directly to the target, using RT calls.
RTAI-Lab project. The server-target communication has been completely inherited from this project and also the first functionalities implemented remind of those accessible through the XRTAI-Lab grafic interface. Having a practice with this tool will help in understanding the implementation of RTAI-XML.