Study of a mixed parallel and serial data transmission in trigger system of Beijing Spectrometer Ⅲ

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 stab