Design Of Optical Data Transmission System For RPC Readout Electronics In DayaBay Neutrino Experiment

This thesis mainly discusses the design, develop and test of the optical data transmission system in RPC readout electronics for Daya Bay neutrino experiment.The RPC readout electronics insists of three parts: Front-End-Card, ROT and VME Modules (including ReadOut Module and RPC Trigger Module). FEC collects RPC detector signals and transmit to ROT through a twist-cable. ROT processes up to 15 FEC's data, and transmits these data to VME Module through optical fiber.The optical data transmission system includes USB optical transmission testing board, optical child board and ROT. USB optical transmission testing board is used to test the optical chips we selected, and it provides USB interface to communicate with PC; optical child board is used to implement the optical transmission function. The independent design makes it easier to debug, install and maintenance; ROT is a part of RPC readout electronic system, it provides interface to FECs. These three parts compose the optical data transmission system, and also can be used to test the other parts in RPC readout electronic system.At the beginning, the brief introduction of the RPC readout electronic system is given, includes the design requirements of FEC, ROT and VME Module. The necessary and importance of the optical data transmission system design is introduced also.The main points of the thesis are the hardware design of optical data transmission system, logic design of FPGA, and system testing method and result. In the part of hardware design, the FPGA chip and FPGA's logic design, what we used to satisfy the system requirements, including USB interface design, capacity of data buffer, configuration scheme of FPGA, optical transmission control and processing more than one connection, are introduced. On the USB optical transmission testing board, we design FPGA logic base on USB interface for command sending , data upload, optical transmission function self-test and simulation of FEC connection test; On ROT, LVDS chips are used to receive FEC data ,and two FPGAs are used to deal with FEC data/status signals and trigger signals independently .At last, this thesis introduces the test method, procedure and results for optical data transmission system, also introduces the RPC electronics prototype testing system. According to the test results, the requirements for optical data transmission system are achieved.The primary results of the thesis are as follows.(1) In the design of optical data transmission system and readout control system of RPC electronics, the programmable of FPGA is well used, to integrate the optical transmission control, data readout control and self-test function in one chip. This makes the design simple and reliable.(2) Use USB optical transmission testing board with PC to test the optical transmission performance, at the same time combine ReadOut Transceiver and Front-End-Card together to build up a testing system for the development of RPC readout electronic.(3) Optical module is the important part of the design. The optical module is designed as a child board, which makes it easier to debug, install and work.