HDB3的编码解码规则,先将消息代码变换成AMI码，若AMI码中连0的个数小于4,此时的AMI码就是HDB3码 -HDB3 coding and decoding rules, the first message code is converted into AMI code, even if the AMI code number is less than 4 0, then the AMI code is HDB3 code