Background Modern particle physics experiments are driving a rapid increase in the channel counts and data rates of front-end electronics, posing severe challenges for the reliable, high-speed aggregation of massive volumes of detector data. Existing data readout systems based on conventional bus architectures are limited in transmission bandwidth and scalability, rendering them insufficient for next-generation experiments.

Purpose This study aims to overcome these bandwidth and scalability limitations by developing a flexible, high-speed data aggregation method based on the VPX (VME International Trade Association eXpanded) bus architecture, in order to meet the demand of next-generation particle physics experiments for the large-scale aggregation of front-end electronics data.

Methods A hierarchical and scalable aggregation system was constructed, in which front-end data are progressively aggregated and reorganized through optical fibers and high-speed serial links, and the final aggregated frames are routed to a remote server through a switching network. Primary boards receive data frames from the front-end electronics through bidirectional optical links at up to 1 Gbps per link; on each primary board, a dedicated module performs first-level aggregation and reorganization of multi-channel frames using a purpose-designed aggregation frame structure and a dynamic reorganization mechanism. This design adapts automatically to different detector types and supports variable-length data frames and configurable channel counts. The aggregated frames are then transmitted to secondary boards over high-speed backplane serial links at up to 10 Gbps per link, where they undergo a second level of aggregation before being forwarded over 40 Gbps Ethernet to the remote data-acquisition and storage server. By deploying identical hardware at every level, differentiated only by configurable device IDs, the system allows both the number of aggregation levels and the channel count to be flexibly scaled.

Results Test results show that the aggregation-link transmission efficiency reaches up to 97%, the bit error rate after two-level aggregation is better than 3.080×10⁻¹⁵, and the total output data transmission rate reaches up to 40 Gbps. Moreover, both the number of aggregation levels and the channel count can be freely expanded.

Conclusions The proposed VPX-based method provides a flexible and scalable framework for high-speed detector data readout. By combining a hierarchical architecture with a dynamic frame reorganization mechanism, it achieves high transmission efficiency and reliability while allowing the aggregation levels and channel counts to be freely expanded, thereby satisfying the demand of next-generation particle physics experiments for the large-scale aggregation of front-end electronics data.