Write a serial program, after restart the computer, a serial port to accept less than information, this is how to return a responsibility?

Just send a message with a serial port tools at this time in the past, then open your serial procedures, if not restart the computer, the program has been can normal send and receive messages, this is how one and the same?

Is my own program problem?

CodePudding user response:

 
Int CHTDLPCard: : OpenPort ()//open the serial port 
{
Cstrings strComm; 
Int die; 
Die=: : GetPrivateProfileInt (" HARDWARE ", "card serial number," 0, ". \ \ card. Ini "); 
StrComm. The Format (" % s % d ", "COM", die); 
M_hCom=CreateFile (strComm,//COM1 port 
GENERIC_READ | GENERIC_WRITE,//allow to read and write 
0,//exclusive way 
NULL, 
OPEN_EXISTING,//open rather than create 
0,//synchronously 
NULL); 

Int a=GetLastError (); 
If (m_hCom==INVALID_HANDLE_VALUE) 
{
AfxMessageBox (" card serial ports open failure "); 
M_bOpen=FALSE; 
Return FALSE; 
} 
//else 
//AfxMessageBox (" open the serial port success "); 

SetCommMask (m_hCom EV_RXCHAR); 
//clean out the input and output buffer 
PurgeComm (m_hCom, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR); 

SetupComm (m_hCom, 2048, 2048);//input buffer and the size of the output buffer is 1024 
COMMTIMEOUTS TimeOuts. 
//set read timeout 
TimeOuts. ReadIntervalTimeout=MAXDWORD;//set timeout interval for the biggest, the total timeout is set to 0, will cause the ReadFile returns immediately and complete the operation 
TimeOuts. ReadTotalTimeoutMultiplier=1; 
TimeOuts. ReadTotalTimeoutConstant=5; 
//set to write timeout 
TimeOuts. WriteTotalTimeoutMultiplier=1; 
TimeOuts. WriteTotalTimeoutConstant=5; 
SetCommTimeouts (m_hCom, & amp; TimeOuts);//set the timeout 
GetCommState (m_hCom, & amp; DCB); 
DCB. BaudRate=m_nBaud;//baud rate to 9600 
DCB. ByteSize=m_nDataBits;//each byte has eight 
DCB. Parity=m_nParity;//and white parity bit 
DCB. StopBits=m_nStopBits;//stop bit 
SetCommState (m_hCom, & amp; DCB); 
M_bOpen=TRUE; 

The COMSTAT COMSTAT; 
DWORD dwErrorFlags=0; 
ClearCommError (m_hCom, & amp; DwErrorFlags, & amp; The ComStat); 

return 1; 
} 



Int CHTDLPCard: : SendData publishes the event (HANDLE com serial number/* */, 
Function code BYTE bFun/* */, 
BYTE bDataLen/* */data length, 
PbData BYTE */* *///) to send data, such as SendData publishes the event (com, 0 x01, 0, NULL) 
{
//check parameter 
If (bDataLen & lt; 0) 
return 0; 

//total target send length 
Int iTxLen=0 
+ 2//byte header 
+ 1//function code 
+ 1//bytes 
+ bDataLen//data length 
+ 2//check 
+ 2//word goeldi 
+ 0; 

//application buffer 
BYTE * pTxData=https://bbs.csdn.net/topics/new BYTE [iTxLen]; 

//send data structure frame 
Int iOfst=0; 

PTxData [iOfst]=0 xc1; IOfst++;//byte header 
PTxData [iOfst]=0 xc2; IOfst++; 

PTxData [iOfst]=bFun; IOfst++;//function code 

PTxData [iOfst]=bDataLen + 2;/* * a + two check/iOfst++;//bytes 

Memcpy (pTxData + iOfst pbData, bDataLen); IOfst +=bDataLen;//data 

{//computing parity 
Uint16_t checksum=getChecksum (pTxData iOfst); 

//ULONG uSumL=0;//and the cumulative of all data before 
//for (int n=0; N & lt; IOfst; N++) {uSumL +=pTxData [n]. } 
////low (high 16 + 16) after the 
//WORD wSum=(WORD) (~ (HIWORD (uSumL) + LOWORD (uSumL))); 

# ifdef _BIG_ENDIAN//big end model 
PTxData [iOfst]=checksum & gt;> 8; IOfst++; 
PTxData [iOfst]=checksum; IOfst++; 
//pTxData [iOfst]=HIBYTE (wSum); IOfst++; 
//pTxData [iOfst]=LOBYTE (wSum); IOfst++; 
# the else//! _BIG_ENDIAN//small side mode 
PTxData [iOfst]=checksum & gt;> 8; IOfst++; 
PTxData [iOfst]=checksum; IOfst++; 
//pTxData [iOfst]=LOBYTE (wSum); IOfst++; 
//pTxData [iOfst]=HIBYTE (wSum); IOfst++; 
# endif 

} 

PTxData [iOfst]=0 x0a; IOfst++;//word goeldi 
PTxData [iOfst]=0 x0d; IOfst++; 


//COMSTAT COMSTAT;//clean up buffer 
//DWORD dwErrorFlags; 
//ClearCommError (m_hCom, & amp; DwErrorFlags, & amp; The ComStat); 
//PurgeComm (m_hCom, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR); 

//here with serial communication interface to send data 
DWORD bytesWritten; 
Bool ret=WriteFile (com, pTxData iOfst, & amp; BytesWritten, 0); 
//end cleanup 
The delete [] pTxData; 
If (ret) 
Return 1; 
The else 
return 0; 
} 

CodePudding user response:

Is I did not open serial port? Or is a computer problem, the first open the serial port have anything special to do, I didn't write in the program?

I send data, neither program executes instructions, also do not return information,

Use a serial port monitoring software to see the next, only issued by the ministry of information, not read information

CodePudding user response:

Wrong here?

I found that when performing SetCommState is a program error, which is set when a serial port to the mistake, check again carefully found Settings DCB. StopBits attribute direct assignment 1, but in fact it doesn't mean stop bit is 1, 1.5, but about StopBits description is like this: DCB, StopBits//two stop bit 0=1, 1.5, 2, when the StopBits value of 0 is on behalf of the stop bit is 1, when the value of 1 represents the stop bit is 1.5, and the computer did not 1.5 this setting, so SetCommState error, namely initialize serial port without success,
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The original link: https://blog.csdn.net/kfhzy/article/details/11607545

CodePudding user response:

Before GetCommState DCB ascribed value DCBlength

DCB DCB={sizeof (DCB)};
GetCommState (m_hCom, & amp; DCB);