串口问题：如何对数据进行校验？

[mj_hc]

我现在要用串口传送2M的文件，怎么进行校验呢？如果用寄偶校验，发现错误后要重新传送，怎么知道要传送哪段呢？（每次传送512字节数据）

[zjg751206]

一般API函数和控件设置时都有奇偶检验的，一般为1位。使用2进制分解文件传送。发完后比较大小也行。使用默认的奇偶检验吧

[lif2000]

两边都要收发消息
A：消息打包，512字节一次，自己计算几偶校验位。受到对方的继续发送消息则继续打包发送，反之重新发送已经当前包的内容。
B:受消息，检查几偶校验位，如果正确发送继续消息，如果错误发送重新发送消息。

一个循环旧搞定了

[duyhui]

发送的时候512字节为一帧，加上帧头帧尾，然后在帧尾前加上校验，可以是奇偶校验，CRC16什么的，你可以自己定。然后在接收端要进行去掉帧头帧尾，算校验再比较就可以了，如果结果一样，就没问题，不一样再重发该帧。

[zhangnanonnet]

一般传输可以用CRC检验，但需要双方都进行校验

void ZComm::crc_16(BYTE *data, int length, BYTE *reply)
{
static WORD CRCTABLE[256]={ 0xF078,0xE1F1,0xD36A,0xC2E3,0xB65C,0xA7D5,0x954E,0x84C7,
0x7C30,0x6DB9,0x5F22,0x4EAB,0x3A14,0x2B9D,0x1906,0x088F,
0xE0F9,0xF170,0xC3EB,0xD262,0xA6DD,0xB754,0x85CF,0x9446,
0x6CB1,0x7D38,0x4FA3,0x5E2A,0x2A95,0x3B1C,0x0987,0x180E,
0xD17A,0xC0F3,0xF268,0xE3E1,0x975E,0x86D7,0xB44C,0xA5C5,
0x5D32,0x4CBB,0x7E20,0x6FA9,0x1B16,0x0A9F,0x3804,0x298D,
0xC1FB,0xD072,0xE2E9,0xF360,0x87DF,0x9656,0xA4CD,0xB544,
0x4DB3,0x5C3A,0x6EA1,0x7F28,0x0B97,0x1A1E,0x2885,0x390C,
0xB27C,0xA3F5,0x916E,0x80E7,0xF458,0xE5D1,0xD74A,0xC6C3,
0x3E34,0x2FBD,0x1D26,0x0CAF,0x7810,0x6999,0x5B02,0x4A8B,
0xA2FD,0xB374,0x81EF,0x9066,0xE4D9,0xF550,0xC7CB,0xD642,
0x2EB5,0x3F3C,0x0DA7,0x1C2E,0x6891,0x7918,0x4B83,0x5A0A,
0x937E,0x82F7,0xB06C,0xA1E5,0xD55A,0xC4D3,0xF648,0xE7C1,
0x1F36,0x0EBF,0x3C24,0x2DAD,0x5912,0x489B,0x7A00,0x6B89,
0x83FF,0x9276,0xA0ED,0xB164,0xC5DB,0xD452,0xE6C9,0xF740,
0x0FB7,0x1E3E,0x2CA5,0x3D2C,0x4993,0x581A,0x6A81,0x7B08,
0x7470,0x65F9,0x5762,0x46EB,0x3254,0x23DD,0x1146,0x00CF,
0xF838,0xE9B1,0xDB2A,0xCAA3,0xBE1C,0xAF95,0x9D0E,0x8C87,
0x64F1,0x7578,0x47E3,0x566A,0x22D5,0x335C,0x01C7,0x104E,
0xE8B9,0xF930,0xCBAB,0xDA22,0xAE9D,0xBF14,0x8D8F,0x9C06,
0x5572,0x44FB,0x7660,0x67E9,0x1356,0x02DF,0x3044,0x21CD,
0xD93A,0xC8B3,0xFA28,0xEBA1,0x9F1E,0x8E97,0xBC0C,0xAD85,
0x45F3,0x547A,0x66E1,0x7768,0x03D7,0x125E,0x20C5,0x314C,
0xC9BB,0xD832,0xEAA9,0xFB20,0x8F9F,0x9E16,0xAC8D,0xBD04,
0x3674,0x27FD,0x1566,0x04EF,0x7050,0x61D9,0x5342,0x42CB,
0xBA3C,0xABB5,0x992E,0x88A7,0xFC18,0xED91,0xDF0A,0xCE83,
0x26F5,0x377C,0x05E7,0x146E,0x60D1,0x7158,0x43C3,0x524A,
0xAABD,0xBB34,0x89AF,0x9826,0xEC99,0xFD10,0xCF8B,0xDE02,
0x1776,0x06FF,0x3464,0x25ED,0x5152,0x40DB,0x7240,0x63C9,
0x9B3E,0x8AB7,0xB82C,0xA9A5,0xDD1A,0xCC93,0xFE08,0xEF81,
0x07F7,0x167E,0x24E5,0x356C,0x41D3,0x505A,0x62C1,0x7348,
0x8BBF,0x9A36,0xA8AD,0xB924,0xCD9B,0xDC12,0xEE89,0xFF00};
WORD CRCVal,i;

CRCVal=0;
for(i=0;i<length;i++) CRCVal=CRCTABLE[(CRCVal^=data[i]&0xFF)&0xFF]^(CRCVal>>8);
reply[0]=CRCVal%256;
reply[1]=CRCVal/256;
}