一 、缘由 当前在查询或者检索下相关协议时，多偏重于描述性，本文通过实际案例和测试 详细接收一下 YMODEM协议的具体实现
第一步 握手 准备发送，接收方 间隔2秒发送 字符C 请求帧
发送端：接收到后 发送文件名和文件大小 Demo_Code.bin 起始帧
01 00 FF 44 65 6D 6F 5F 43 6F 64 65 2E 62 69 6E 00 33 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 7C 5C
接收端 响应 ACK 06
第二步 请求发送数据 接收端 发送C：
发送数据
02 01 FE 48 07 00 20 CD 41 00 08 F5 43 00 08 9D 43 00 08 F1 43 00 08 7D 42 00 08 77 46 00 08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 19 44 00 08 81 42 00 08 00 00 00 00 F7 43 00 08 2D 45 00 08 E7 41 00 08 E7 41 00 08 E7 41 00 08 E7 41 00 08 E7 41 00 08 E7 41 00 08 E7 41 00 08 E7 41 00
