说明：  对MODBUS-RTU协议的接收数据进行CRC验证，可指定数据长度，或自动判断，支持广播地址判断，接收的数据包前和包后包含多余数据时可自动跳过，获取正确的数据包。
(CRC validation of the received data of MODBUS-RTU protocol can specify the data length or automatic judgment, support the broadcast address judgment, and automatically skip before and after the received data packet when it contains redundant data to obtain the correct data packet.)