说明：  中国银联直联POS开发规范，定义了界面要求和卡业务操作流程，及对各部分POS业务所对应8583报文做了详细的说明
(China UnionPay POS Direct the development of norms, the definition of the interface card requirements and operational flow, and for each of the POS business message corresponding to 8583 to do such a detailed description of)