Distributed real-time control and data acquisition of free-electron laser beams

Implementation of a feedback control scheme and its associated user-interfa ce and data acquisition modules in a distributed real-time computing enviro nment are described. The distributed system consists of an ethernet network interconnecting real-time processor modules to host workstations and other embedded controllers. The goal of the feedback control scheme is to mainta in positions of the electron beam in the middle of the vacuum chamber in th e presence of electromagnetic interference and noise. Technical details of implementing the data acquisition and control scheme and their integration with the existing control system modules are presented, along with experime ntal results.