说明：  工控中经常用到modelbus通信，在不使用第三方控件的情况下实现简单modelbus通信的CRC校验位自动计算，加入工程修改命名空间可直接使用！
(In the industrial control, we often use the mode bus communication. Without using the third-party control, we can realize the automatic calculation of CRC check bit of simple mode bus communication. We can use it directly by adding the modified project namespace!)