modbus协议CRC16校验函数协议

CRC函数：

unsigned short CheckCRC(unsigned char *pData,unsigned int siLen) { if (NULL == pData || siLen <= 0) { return 0; } unsigned short u16CRC = 0xFFFF; for (int i = 0; i < siLen; i++) { u16CRC ^= (unsigned short)(pData[i]); for(int j = 0; j <= 7; j++) { if (u16CRC & 0x0001) { u16CRC = (u16CRC >> 1) ^ 0xA001; } else { u16CRC = u16CRC >> 1; } } } unsigned short siRet = 0; siRet = (u16CRC & 0x00FF) << 8; siRet |= u16CRC >> 8; return siRet; }

实例：

int main() { unsigned char data[] = {0x55,0xFE,0xFE,0x03,0x05,0x01}; unsigned short CRC = CheckCRC(data, sizeof(data)); printf("CRC = %x \r\n", CRC); return 0; }

运行结果：
【modbus协议CRC16校验函数】