SLAC, Menlo Park, California, USA
Among the several acquisition services available with SLAC’s high beam rate accelerator, all of which are contemplated in the acquisition service EPICS support package, resides the new Advanced Telecommunications Computing Architecture (ATCA) Beam Line Data (BLD) service. BLD runs on top of SLAC’s common platform software and firmware, and communicates with several high-performance systems (i.e. MPS, BPM, LLRF, timing, etc.) in LCLS, running on a 7-slot ATCA crate. Once linked with an ATCA EPICS IOC and with the proper commands called in the IOC shell, it initializes the BLD FPGA logic and the upper software stack, and makes PVs available allowing the control of the BLD data acquisition rates, and the starting of the BLD data acquisition. This service permits the forwarding of acquired data to configured IP addresses and ports in the format of multicast network packets. Up to four BLD rates can be configured simultaneously, each accessible at its configured IP destination, and with a maximum rate of 1MHz. Users interested in acquiring any of the four BLD rates will need to register in the corresponding IP destination for receiving a copy of the multicast packet on their respective receiver software. BLD has allowed data to be transmitted over multicast packets for over a decade at SLAC, but always at a maximum rate of 120 Hz. The present work focuses on bringing this service to the high beam rate high-performance systems using ATCAs, allowing the reuse of many legacy in-house-developed client software infrastructures.
