Fast data transmission in dynamic data acquisition system for plasma diagnostics

摘要

This paper describes architecture of a new data acquisition system (DAQ) targeted mainly at plasma diagnostic experiments. Modular architecture, in combination with selected hardware components, allows for straightforward reconfiguration of the whole system, both offline and online. Main emphasis will be put into the implementation of data transmission subsystem in said system. One of the biggest advantages of described system is modular architecture with well defined boundaries between main components: analog frontend (AFE), digital backplane and acquisition/control software. Usage of a FPGA chips allows for a high flexibility in design of analog frontends, including ADC ? FPGA interface. Data transmission between backplane boards and user software was accomplished with the use of industry-standard PCI Express (PCIe) technology. PCIe implementation includes both FPGA firmware and Linux device driver. High flexibility of PCIe connections was accomplished due to use of configurable PCIe switch. Whenever it's possible, described DAQ system tries to make use of standard off-the-shelf (OTF) components, including typical x86 CPU & motherboard (acting as PCIe controller) and cabling.