Software Architecture for High-Speed Synchronous Network Instrumentation

Particle detectors and other large-scale experimental apparatus employ a large number of channels producing very high data rates. A high-speed, synchronous data acquisition system is needed that uses commodity high-bandwidth networks for high-rate transmission of collected data from the data source to storage or control systems. Detector elements must be synchronized to within 10 ns and event triggering to within 100 ns, and an Event Builder must track detection events and send out global triggers to locally store captured data at each detector node. Crossfield Technology proposes a standards-based, event-driven software and network architecture that supports sub-nanosecond synchronization between detector elements across high-speed network switch fabrics. IEEE 1588 Precision Time Protocol (PTP) is used for time transfer and synchronization between a network-based master clock and clocks integrated into client DAQ devices on the network. With a physical layer implementation, PTP can support precision time transfer with sub-ns precision. The IEEE 1451 Transducer Electronic Data Sheets (TEDS) forms a basis to streamline the process of network configuration, digitizer identification, and data acquisition. Remote Direct Memory Access (RDMA) Protocol is used to transfer data captured in high-speed data buffers across the network to computer systems for analysis or networked attached storage for permanent storage. Commercial Applications and Other Benefits: Commercial and government research laboratories will benefit from a standards- based network architecture that can be used to capture high-speed events and synchronize detector elements to sub-nanosecond precision.