A dual-ring network design for the fast orbit feedback system of the storage ring

Building reliable fast orbit feedback (FOFB) systems to offer high stability of the beam orbit becomes more challenging for the diffraction-limited storage ring due to the smaller beam size. The beam position measurement and control (BPMC) processor has been developed to streamline the FOFB system architecture by integrating BPM (Beam Position Monitor) electronics and an orbit feedback controller. This paper designs a hierarchical dual-ring network topology based on BPMC processors using parameters derived from the storage ring of the Hefei Advanced Light Facility. To reduce latency and prevent data transmission collisions, we propose a multi-forwarding communication scheme and a communication controller design in a field-programmable gate array. Experimental results verify that this topology operates reliably with the multi-forwarding scheme, providing an approximate communication latency as low as 17.336 mu s to support the 30 kHz orbit feedback update rate.