北京谱仪中各探测器电子学系统向触发系统传输大量并行信号,需要采用并串结合型光纤传输方法,以达到断开地回路,提高系统及线路抗干扰能力,延长传输距离的目的.对此种传输方法的误码率、报错与恢复、延时一致性和相位稳定性等关键问题进行了深入研究,得到确切参数,并提出了单路出错自恢复同步的解决方法,增强了系统的耐用性.同时发现各线路间传输延迟有半个周期的不一致,因此在接收端应把采样时钟上升沿调整在所有解出数据都稳定的时刻.此方法可满足北京谱仪工程的实际需要.

Serial optical fiber transmission technology will be used to transfer data from the detector electronics systems to the trigger system in the Beijing Spectrometer Ⅲ. This technology has the advantages of cutting off the ground loops between the electronics systems and the trigger system, improving the system immunity to electro-magnetic interference and lengthening the transfer distance.Some important aspects of this technology are carefully studied, such as the bit-error-rate, error report,synchronization-back,delay skew of channels and phase stability.Design for single line self-synchronizing back is given,which makes the system more robust.The skew of channels is half a period.So the synchronous parellel data can be gotten if the rising of sample clock is set at the middle of the stable time of all deserialized data.This method can meet the require of BES Ⅲ data transmission.