comctrol.cpp

控制硬件仪器的软件,可以用于测试试验.是Chroma公司的交流电源

// ComCtrol.cpp: implementation of the CComCtrol class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "ComCtrol.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CComCtrol::CComCtrol()
{
	m_hCommHandle=INVALID_HANDLE_VALUE;
	m_bOpen=false;
}

CComCtrol::~CComCtrol()
{
	if(m_hCommHandle!=INVALID_HANDLE_VALUE)
		CloseHandle(m_hCommHandle) ;
}
bool CComCtrol::InitPort(CString strPort,DWORD nBaudRate,BYTE nByteSize,BYTE nParity,BYTE nStopBits)
{
	COMMTIMEOUTS TimeOuts;
	m_strPort = strPort ;
	if(IsValid())
	{
		ClosePort() ;
	}
	m_hCommHandle=CreateFile(m_strPort, GENERIC_READ | GENERIC_WRITE, 0, NULL,
		OPEN_EXISTING,0 , NULL); // 重叠方式FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED

	if(m_hCommHandle==INVALID_HANDLE_VALUE)
		return FALSE;

	SetupComm(m_hCommHandle,1023,1023);
	SetCommMask(m_hCommHandle, EV_RXCHAR);
   	GetCommTimeouts(m_hCommHandle,&TimeOuts);   //读超时连接设置。
	// 把间隔超时设为最大，把总超时设为0将导致ReadFile立即返回并完成操作
	TimeOuts.ReadIntervalTimeout=1000; 
	TimeOuts.ReadTotalTimeoutMultiplier=1000; 
	TimeOuts.ReadTotalTimeoutConstant=200; 

	//设置写超时以指定WriteComm成员函数中的GetOverlappedResult函数的等待时间
	TimeOuts.WriteTotalTimeoutMultiplier=1000;
	TimeOuts.WriteTotalTimeoutConstant=200;
    SetCommTimeouts(m_hCommHandle, &TimeOuts);

	DCB dcb;
	if(!GetCommState(m_hCommHandle, &dcb))
		return FALSE;

	dcb.BaudRate = nBaudRate; // 数据传输速率
	dcb.ByteSize = nByteSize; // 每字节位数NOPARITY TWOSTOPBITS
	dcb.Parity   = nParity;
	dcb.StopBits = nStopBits;
	if(!SetCommState(m_hCommHandle, &dcb))
	{
		ClosePort() ;
		return false ;
	}
	PurgeComm(m_hCommHandle,PURGE_RXCLEAR); //清空缓存*/
	m_bOpen=true;
	return true ;
}

DWORD CComCtrol::SendCommand(char *szBuffer, DWORD dwLength)
{
	if(!IsValid())
		return 0;
	BOOL fState=false;
	DWORD length=dwLength;
	COMSTAT ComStat;
	DWORD dwErrorFlags;
	ClearCommError(m_hCommHandle,&dwErrorFlags,&ComStat);
	PurgeComm(m_hCommHandle,PURGE_RXCLEAR);
	fState=WriteFile(m_hCommHandle,szBuffer,length,&length,NULL);
	
	if(!fState)
	{
		if(GetLastError()==ERROR_IO_PENDING)
		{
			GetOverlappedResult(m_hCommHandle,NULL,&length,TRUE);// 
		}
		else
			length=0;
	}
	return length;
}


DWORD CComCtrol::ReceiveCommand(char *szBuffer, DWORD dwLength)
{
	if(!IsValid())
		return 0;
	DWORD length=0;
	char c ;
	int i = 0;
	DWORD nLen = 0 ;
	COMSTAT ComStat;
	DWORD dwErrorFlags;
	ClearCommError(m_hCommHandle,&dwErrorFlags,&ComStat);
  	DWORD dwStart=GetTickCount();
	while(1)
	{
		if(ReadFile( m_hCommHandle,&c,1,&nLen,0))
		{
			szBuffer[i++] = c;
		}
		if(c==0x0a||c==0x0d)                                                                                             
			break;
		if(i>30)
			break;
	    if( GetTickCount()-dwStart > 1200 )
		   break;
	}
	length = i ;
	return length;
}


void CComCtrol::ClosePort()
{
	if(m_hCommHandle!=INVALID_HANDLE_VALUE)
		CloseHandle(m_hCommHandle) ;
	m_hCommHandle = INVALID_HANDLE_VALUE;
}

bool CComCtrol::IsValid()
{
	if(	m_hCommHandle == INVALID_HANDLE_VALUE)
		return false ;
	return true ;
}