读取HL-G1测量值（例程）RS485通信 C++串口通信

        本例中使用windows系统电脑作为上位机与松下激光位移产品HL-G1进行串口通信。HL-G1通过 RS485-RS232/USB 转接板与电脑相连，采用松下自定义协议进行通信。windows系统向传感器发出指令后会接受到返回数据，本例发送返回位移测量值命令。

        以下为windows环境下采用C++串口通信例程，供读者参考。

#include <iostream>
#include <string>
#include <windows.h>
#include <cstdlib>class TFSerialPort
{
public:TFSerialPort(std::string portNum, DWORD baudRate = 38400, BYTE byteSize = 8, BYTE parityBit = NOPARITY, BYTE stopBit = ONESTOPBIT){m_portNum = portNum;m_dwBaudrate = baudRate;m_byteSize = byteSize;m_parityBit = parityBit;m_stopBit = stopBit;m_bOpen = false;}~TFSerialPort(){}public:HANDLE m_hCom;          //句柄std::string m_portNum;  //串口号DWORD m_dwBaudrate;     //波特率BYTE  m_byteSize;       //数据位BYTE  m_parityBit;      //校验位BYTE  m_stopBit;        //停止位bool  m_bOpen;          //串口开关标志//打开com口bool openCom(){m_hCom = CreateFileA(m_portNum.c_str(), GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);if (m_hCom == INVALID_HANDLE_VALUE){}else{DCB dcb;if (!SetupComm(m_hCom, 1024, 1024)){}else{}GetCommState(m_hCom, &dcb);dcb.BaudRate = m_dwBaudrate;dcb.ByteSize = m_byteSize;dcb.Parity = m_parityBit;dcb.StopBits = m_stopBit;if (!SetCommState(m_hCom, &dcb)){return false;}else{PurgeComm(m_hCom, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);m_bOpen = true;return true;}}}//关闭com口void closeCom(){CloseHandle(m_hCom);}//写入数据bool writeToCom(BYTE data[], DWORD dwLength){DWORD dwError = 0;if (ClearCommError(m_hCom, &dwError, NULL) && dwError > 0){PurgeComm(m_hCom, PURGE_TXABORT | PURGE_TXCLEAR);}DWORD dwTx = 0;BOOL ret = FALSE;ret = WriteFile(m_hCom, data, dwLength, &dwTx, NULL);if (ret == FALSE){return false;}else{return true;}}//读取数据bool readFromCom(BYTE readBuffer[], DWORD dwLength){COMSTAT comStat;DWORD dwError = 0;if (ClearCommError(m_hCom, &dwError, &comStat) && dwError > 0)      //清除错误{PurgeComm(m_hCom, PURGE_RXABORT | PURGE_RXCLEAR);               //清空缓冲区}DWORD dwRx = 0;		                                                // 读入的字节数BOOL ret = FALSE;ret = ReadFile(m_hCom, readBuffer, dwLength, &dwRx, NULL);	        // 读入数据if (ret == TRUE){return true;}else{return false;}}
};int main()
{std::string comPort = "COM6";               //定义COM口TFSerialPort tfserialPort(comPort);BYTE sendBuff[] = {"%01#RMD**\r"};          //发送空间，写入获取距离指令BYTE recvBuff[20] = { 0 };                  //接收空间CHAR order = NULL;tfserialPort.openCom();                     //打开COM口//循环发送接收串口数据并显示while (true){//发送命令printf("Touch the Enter key to send request:");scanf_s("%c", &order);if (order != NULL){ tfserialPort.writeToCom(sendBuff, 10); }          //发送获取距离指令else{ break; }//接收命令tfserialPort.readFromCom(recvBuff, 18);if (recvBuff[0] == '%' && recvBuff[17] == '\r'){printf("result: ");for ( int i = 7 ; i < 11 ; i++){ printf("%c", recvBuff[i]); }printf(".");for (int i = 11; i < 15; i++){ printf("%c", recvBuff[i]); }printf("\n");}else{ printf("No Data!!! \r"); }}tfserialPort.closeCom();                    //关闭端口system("pause");                            //挂机return 0;
}

        运行结果如下图所示

        图中从上至下依次显示无量块放置、放置1mm厚量块 、放置2mm厚量块 、放置3mm厚量块情况下的四个测量结果，测量结果单位为毫米，四个测量值间距约为1mm。