| China Spallation Neutron Source (CSNS) is a large scientific equipment which produces pulsed neutron source by targeting high-energy protons. General Purpose Powder Diffractometer (GPPD) is one of the three earliest constructed CSNS diffractometers, which fullfills the industry and physics requirements from physics nanoscience, chemistry, biology and materials science. GPPD adopts Scintillator as Symptom Scale of Neurotransmitter Deficiency (SSND), the detected light signals convert into electrical information before amplifying by Photomultiplier tubes. Then the flight time of neutron obtained by electronics system move to the data acquisition system, which is available for users to analysis.According to the background of GPPD electronics system, through studing and research on chip, the paper designs a electronic control circuit which is based on Xilinx Spartan6Series XC6SLX75T FPGA, which main implementes real-time signal tranmission and user data transmission under the enviroment of ISE14.4with the control circuit. Real-time signal tranmission is optical fiber transmission based on Aurora8B/10B protocol at the line speed of2.5Gbps. It will eliminate a large number of cables laying work by using the existing optical fiber to transmit real-time signal. User data tranmission to PC for user is based on TCP/IP Internet Protocol. It will reduce the CPU load and speed up network performance through FPGA to implement TCP/IP Internet Protocol, because the work is belong to host CPU is done by control circuit.The propagation delay tests and jitter tests of real-time signal optical fiber tranmission and TCP/IP Internet protocol tranmission tests are implemented. Repeated propagation delay and jitter tests show that the maximum propagation delay is less than600ns and that the maximum jitter is less than4ns, so the results meet the system requirements of the propagation delay less than1μs and the jitters less than0.1μs.TCP/IP internet protocol tranmission is proved right and reliable. |
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