Design and implementation of feedback logic of FOFB for HEPS

Purpose As a fourth-generation light source, High Energy Photon Source (HEPS) has much more stringent requirements to the beam orbit stability in both horizontal and vertical directions than the previous sources due to the much smaller beam sizes.Methods A Fast Orbit FeedBack (FOFB) system, with the closed-loop bandwidth around 500 Hz, is needed to meet the critical requirements. The latency of the FOFB system is the key to achieve these requirements.Results Proper design and implementation of the feedback logic to have low latency is illustrated in the paper. Calculation accuracy is kept in the whole operation except for the last-minute data translation into 32-bit floating point number.