串口通信时会用到一个比较有用的协议-串口复用协议，利用该工具可以很快计算出校验域的值。方便调试及验证协议数据帧是否正确。-Serial communication is used when a more useful protocol- serial multiplexing protocol, the use of the tool can quickly calculate the checksum field value. Facilitate debugging and verification of protocol data frame is correct.