说明：  CDT规约中CRC校验码的正确快速生成对报文解析十分重要。介绍了CDT规约的帧结构，CRC校验码的生成方法， 并给出C语言原程序。
(CRC checksum CDT Statute quickly generate the correct decoding of the importance of the newspaper. Introduced the Statute of the frame structure of CDT, CRC checksum generation method, and gives the original C language program.)