51单片机modbus通讯协议经典案例

#include "main.h" //字地址 0 - 255 (只取低8位) //位地址 0 - 255 (只取低8位) /* CRC 高位字节值表 */ const uint8 code auchCRCHi[] = { 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40 } ; /* CRC低位字节值表*/ const uint8 code auchCRCLo[] = { 0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09, 0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4, 0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3, 0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3, 0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4, 0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A, 0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED, 0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26, 0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60, 0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F, 0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68, 0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5, 0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0, 0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C, 0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B, 0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C, 0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42, 0x43, 0x83, 0x41, 0x81, 0x80, 0x40 } ; uint8 testCoil; //用于测试 位地址1 uint16 testRegister; //用于测试 字址址16 uint8 localAddr = 1; //单片机控制板的地址 uint8 sendCount; //发送字节个数 uint8 receCount; //接收到的字节个数 uint8 sendPosi; //发送位置 uint16 crc16(uint8 *puchMsg, uint16 usDataLen) { uint8 uchCRCHi = 0xFF ; /* 高CRC字节初始化 */ uint8 uchCRCLo = 0xFF ; /* 低CRC 字节初始化 */ uint32 uIndex ; /* CRC循环中的索引 */ while (usDataLen--) /* 传输消息缓冲区 */ { uIndex = uchCRCHi ^ *puchMsg++ ; /* 计算CRC */ uchCRCHi = uchCRCLo ^ auchCRCHi[uIndex] ; uchCRCLo = auchCRCLo[uIndex] ; } return (uchCRCHi << 8 | uchCRCLo) ; }//uint16 crc16(uint8 *puchMsg, uint16 usDataLen) //开始发送 void beginSend(void) { b485Send = 1; //设为发送 sendPosi = 0; if(sendCount > 1) sendCount--; ACC = sendBuf[0]; TB8 = P; SBUF = sendBuf[0]; }//void beginSend(void) //读线圈状态 void readCoil(void) { uint8 addr; uint8 tempAddr; uint8 byteCount; uint8 bitCount; uint16 crcData; uint8 position; uint8 i,k; uint8 result; uint16 tempData; uint8 exit = 0; //addr = (receBuf[2]<<8) + receBuf[3]; //tempAddr = addr & 0xfff; addr = receBuf[3]; tempAddr = addr; //bitCount = (receBuf[4]<<8) + receBuf[5]; //读取的位个数 bitCount = receBuf[5]; byteCount = bitCount / 8; //字节个数 if(bitCount%8 != 0) byteCount++; for(k=0;k<byteCount;k++) {//字节位置 position = k + 3; sendBuf[position] = 0; for(i=0;i<8;i++) { getCoilVal(tempAddr,&tempData); sendBuf[position] |= tempData << i; tempAddr++; if(tempAddr >= addr+bitCount) { //读完 exit = 1; break; } } if(exit == 1) break; } sendBuf[0] = localAddr; sendBuf[1] = 0x01; sendBuf[2] = byteCount; byteCount += 3; crcData = crc16(sendBuf,byteCount); sendBuf[byteCount] = crcData >> 8; byteCount++; sendBuf[byteCount] = crcData & 0xff; sendCount = byteCount + 1; beginSend(); }//void readCoil(void) //读寄存器 void readRegisters(void) { uint8 addr; uint8 tempAddr; uint16 result; uint16 crcData; uint8 readCount; uint8 byteCount; uint8 finsh; //1完成 0出错 uint16 i; uint16 tempData = 0; //addr = (receBuf[2]<<8) + receBuf[3]; //tempAddr = addr & 0xfff; addr = receBuf[3]; tempAddr = addr; //readCount = (receBuf[4]<<8) + receBuf[5]; //要读的个数 readCount = receBuf[5]; byteCount = readCount * 2; for(i=0;i<byteCount;i+=2,tempAddr++) { getRegisterVal(tempAddr,&tempData); sendBuf[i+3] = tempData >> 8; sendBuf[i+4] = tempData & 0xff; } sendBuf[0] = localAddr; sendBuf[1] = 3; sendBuf[2] = byteCount; byteCount += 3; crcData = crc16(sendBuf,byteCount); sendBuf[byteCount] = crcData >> 8; byteCount++; sendBuf[byteCount] = crcData & 0xff; sendCount = byteCount + 1; beginSend(); }//void readRegisters(void) //强制单个线圈 void forceSingleCoil(void) { uint8 addr; uint8 tempAddr; uint16 tempData; uint8 onOff; uint8 i; //addr = (receBuf[2]<<8) + receBuf[3]; //tempAddr = addr & 0xfff; addr = receBuf[3]; tempAddr = addr; //onOff = (receBuf[4]<<8) + receBuf[5]; onOff = receBuf[4]; //if(onOff == 0xff00) if(onOff == 0xff) { //设为ON tempData = 1; } //else if(onOff == 0x0000) else if(onOff == 0x00) { //设为OFF tempData = 0; } setCoilVal(tempAddr,tempData); for(i=0;i<receCount;i++) { sendBuf[i] = receBuf[i]; } sendCount = receCount; beginSend(); }//void forceSingleCoil(void) //设置多个寄存器 void presetMultipleRegisters(void) { uint8 addr; uint8 tempAddr; uint8 byteCount; uint8 setCount; uint16 crcData; uint16 tempData; uint8 finsh; //为1时完成 为0时出错 uint8 i; //addr = (receBuf[2]<<8) + receBuf[3]; //tempAddr = addr & 0xfff; addr = receBuf[3]; tempAddr = addr & 0xff; //setCount = (receBuf[4]<<8) + receBuf[5]; setCount = receBuf[5]; byteCount = receBuf[6]; for(i=0;i<setCount;i++,tempAddr++) { tempData = (receBuf[i*2+7]<<8) + receBuf[i*2+8]; setRegisterVal(tempAddr,tempData); } sendBuf[0] = localAddr; sendBuf[1] = 16; sendBuf[2] = addr >> 8; sendBuf[3] = addr & 0xff; sendBuf[4] = setCount >> 8; sendBuf[5] = setCount & 0xff; crcData = crc16(sendBuf,6); sendBuf[6] = crcData >> 8; sendBuf[7] = crcData & 0xff; sendCount = 8; beginSend(); }//void presetMultipleRegisters(void) //检查uart0数据 void checkComm0Modbus(void) { uint16 crcData; uint16 tempData;