上位机通过RS232 向下位机发送10个字节，下位机回传该10个字节，同时保存10个字节并通过8位led，循环依次显示该10个字节。-The host computer via an RS232 the downward-bit machine to send 10 bytes, the next crew return to the 10 bytes, and at the same time save 10 bytes, looping the 10 bytes by 8 led.