快来帮帮我呀：串口通信问题，在线等

[jianyu807]

一台终端与交换机相连，数据传输用串口(COM1)。
串口设置如下：
设备名：COM1
比特：1200
数据位：7
校验：0
停止位：1

调用下面的函数是老是出错，返回值是3
int OpenComm(const char* pPort/*串口名, const int nBaudRate/* =CBR_1200 */, const int nParity/* =NOPARITY */, const int nByteSize/* =7 */, const int nStopBits/* =1 */)
{

DCB dcb; // 串口控制块
COMMTIMEOUTS timeout;
timeout.ReadIntervalTimeout = 100;
timeout.ReadTotalTimeoutMultiplier = 1;
timeout.ReadTotalTimeoutConstant = 500;
timeout.WriteTotalTimeoutMultiplier = 1;
timeout.WriteTotalTimeoutConstant = 100;
m_hComm = CreateFile(pPort, // 串口名称或设备路径
GENERIC_READ ¦ GENERIC_WRITE,// 读写方式
0, // 共享方式：独占
NULL, // 默认的安全描述符
OPEN_EXISTING, // 创建方式
0, // 不需设置文件属性
NULL); // 不需参照模板文件
if(m_hComm == INVALID_HANDLE_VALUE)
{
return 1; // 打开串口失败
}
if (!GetCommState(m_hComm, &dcb)) // 取DCB
{
return 2;
}
dcb.BaudRate = nBaudRate;
dcb.ByteSize = nByteSize;
dcb.Parity = nParity;
dcb.StopBits = nStopBits;
if (!SetCommState(m_hComm, &dcb)) // 设置DCB
{
return 3;
}
if (!SetupComm(m_hComm, 1024*1, 1024*1))// 设置缓冲区
{
return 4;
}
if (!SetCommTimeouts(m_hComm, &timeout))// 设置超时
{
return 5;
}
return 0;
}
一切硬件连接正常（用超级终端连接正常）
请各位高手帮忙看看是什么问题？ 很急！先谢了！

[JedyWoody]

在 if (!SetCommState(m_hComm, &dcb)) // 设置DCB
{
return 3;
}
之前添加延时试试

[JedyWoody]

设置DCB 一般我用BuilderCommDCB

[JedyWoody]

m_hComm = CreateFile(pPort, // 串口名称或设备路径

HANDLE m_hComm=CreateFile

[yuheng1028]

bool __fastcall OnInitialUpdate(int port)
{
Char szComParams[50];
DCB dcb;
memset(&m_OverlappedRead, 0, sizeof (OVERLAPPED));
memset(&m_OverlappedWrite, 0, sizeof (OVERLAPPED));

m_hIDComDev = NULL;
AnsiString comname="COM"+IntToStr(port);
m_hIDComDev = CreateFile(comname.c_str(), GENERIC_READ|GENERIC_WRITE, 0,
NULL,OPEN_EXISTING, 0, 0);

if (m_hIDComDev == NULL)
{
// AfxMessageBox("Can not open serial port!");
return 1;
}

memset(&m_OverlappedRead, 0, sizeof (OVERLAPPED));
memset(&m_OverlappedWrite, 0, sizeof (OVERLAPPED));
COMMTIMEOUTS CommTimeOuts;
CommTimeOuts.ReadIntervalTimeout=0xFFFFFFFF;
CommTimeOuts.ReadTotalTimeoutMultiplier = 0;
CommTimeOuts.ReadTotalTimeoutConstant = 0;
CommTimeOuts.WriteTotalTimeoutMultiplier = 0;
CommTimeOuts.WriteTotalTimeoutConstant = 5000;
SetCommTimeouts(m_hIDComDev, &CommTimeOuts);
//wsprintf(szComparams, “COM2:9600, n, 8, 1”);

m_OverlappedRead.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
m_OverlappedWrite.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

dcb. DCBlength = sizeof(DCB);
GetCommState(m_hIDComDev, &dcb);
dcb.BaudRate = 9600;
dcb.ByteSize= 8;
dcb.StopBits= ONESTOPBIT;
dcb.Parity=NOPARITY;

//unsigned char ucSet;

//ucSet = (unsigned char) ((FC_RTSCTS&FC_DTRDSR) != 0);
//ucSet = (unsigned char) ((FC_RTSCTS&FC_RTSCTS) ! = 0);
//ucSet = (unsigned char) ((FC_RTSCTS&FC_XONXOFF) ! = 0);

if (!SetCommState(m_hIDComDev, &dcb)||
!SetupComm(m_hIDComDev,10000,10000)||
m_OverlappedRead. hEvent ==NULL||
m_OverlappedWrite. hEvent ==NULL)
{
if (m_OverlappedRead. hEvent != NULL)
CloseHandle(m_OverlappedRead. hEvent);
if (m_OverlappedWrite. hEvent != NULL)
CloseHandle(m_OverlappedWrite. hEvent);

CloseHandle(m_hIDComDev);
return 1;
}
return 0;

[yuheng1028]

看看和你写的有什么不同

[jianyu807]

to yuheng1028(blue) 好像你的程序和我写的程序主要的区别是在超时设置上，我对串口的编程不是太熟，我觉得超时设置对串口的初始化关系不大。

[jianyu807]

to JedyWoody(向前进) 你说的我再试试看由于环境问题我只有到现场去调试。

[JedyWoody]

在实际工作中，你没注意过的东西往往会找你的麻烦