51单片机Modbus_RTU

void presetSingleRegister(void) //设置单个寄存器 { U8 addr; U8 tempAddr; U8 setCount; U16 crcData; U16 tempData; //addr = (receBuf[2]<<8) + receBuf[3]; //tempAddr = addr & 0xfff; addr = receBuf[3]; tempAddr = addr; //& 0xff tempData = ( receBuf[4]<<8 ) + receBuf[5]; setRegisterVal(tempAddr,tempData); sendBuf[0] = localAddr; sendBuf[1] = 6; sendBuf[2] = addr >> 8; sendBuf[3] = addr & 0xff; sendBuf[4] = receBuf[4]; sendBuf[5] = receBuf[5] ; setCount = 6; //共6个字节 crcData = crc16(sendBuf,6); sendBuf[6] = crcData >> 8; sendBuf[7] = crcData & 0xff; sendCount = 8; beginSend(); } //设置多个寄存器 void presetMultipleRegisters(void) { UINT8 addr; UINT8 tempAddr; UINT8 byteCount; UINT8 setCount; UINT16 crcData; UINT16 tempData; 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++) { //SBUF = receBuf[i*2+7]; //SBUF = receBuf[i*2+8]; 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(); }码