win32 SetCommState

网页：

https://msdn.microsoft.com/en-us/library/aa363436(VS.85).aspx

SetCommState 函数
根据设备控制块（device-control block (a DCB structure)）的规范，配置通信设备。
这个函数重新初始化所有的硬件和控制设置。
但是不会清空输出和输入队列。

BOOL WINAPI SetCommState(
  _In_ HANDLE hFile,
  _In_ LPDCB  lpDCB
);

参数：

hFile [in]

指向通信设备的句柄。CreateFile函数返回的句柄。
A handle to the communications device. The CreateFile function returns this handle.

lpDCB [in]

DCB结构体指针，该结构体包含对通信设备的配置信息。

Return value

函数成功，返回非0
函数失败，返回0

Remarks

SetCommState 函数使用 DCB 结构体指定希望的配置
GetCommState 函数返回当前的配置
可以使用GetCommState 返回一个DCB结构体，然后修改需要修改的几个DCB结构体的变量。
这样可以确保DCB结构体中的其他的成员变量有合适的值。
如果DCB结构体的XonChar成员变量和XoffChar成员变量相等，SetCommState函数返回失败。
当SetCommState用来配置8250的时候，对于DCB结构体中的ByteSize 和StopBits 成员函数有如下的限制：
数据的位数必须是5到8位。

Examples

For an example, see Configuring a Communications Resource.

// serialTC.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <windows.h>
#include <tchar.h>
#include <stdio.h>


#if 0
    myDCB.BaudRate = CBR_9600;   // 设置波特率9600  
    myDCB.fBinary = TRUE; // 设置二进制模式，此处必须设置TRUE  
    myDCB.fParity = FALSE; // 支持奇偶校验  
    myDCB.fOutxCtsFlow = FALSE;  // No CTS output flow control  
    myDCB.fOutxDsrFlow = FALSE;  // No DSR output flow control  
    myDCB.fDtrControl = DTR_CONTROL_DISABLE; // No DTR flow control  
    myDCB.fDsrSensitivity = FALSE; // DSR sensitivity  
    myDCB.fTXContinueOnXoff = TRUE; // XOFF continues Tx  
    myDCB.fOutX = FALSE;     // No XON/XOFF out flow control  
    myDCB.fInX = FALSE;        // No XON/XOFF in flow control  
    myDCB.fErrorChar = FALSE;    // Disable error replacement  
    myDCB.fNull = FALSE;  // Disable null stripping  
    myDCB.fRtsControl = RTS_CONTROL_DISABLE;   //No RTS flow control  
    myDCB.fAbortOnError = FALSE;  // 当串口发生错误，并不终止串口读写  
    myDCB.ByteSize = 8;   // 数据位,范围:4-8  
    myDCB.Parity = NOPARITY; // 校验模式  
    myDCB.StopBits = 0;   // 1位停止位  
#endif


void PrintCommState(DCB dcb)
{
    //  Print some of the DCB structure values
    _tprintf( TEXT("\n BaudRate = %d, \n ByteSize = %d, \n Parity = %d, \n StopBits = %d\n"), 
              dcb.BaudRate, 
              dcb.ByteSize, 
              dcb.Parity,
              dcb.StopBits );

    _tprintf( TEXT("\n fBinary = %d, \n fParity = %d, \n fOutxCtsFlow = %d, \n fDtrControl = %d\n"), 
              dcb.fBinary, 
              dcb.fParity, 
              dcb.fOutxCtsFlow,
              dcb.fDtrControl );


    _tprintf( TEXT("\n fDsrSensitivity = %d, \n fTXContinueOnXoff = %d, \n fOutX = %d, \n fInX = %d\n"), 
              dcb.fDsrSensitivity, 
              dcb.fTXContinueOnXoff, 
              dcb.fOutX,
              dcb.fInX );

    _tprintf( TEXT("\n fErrorChar = %d, \n fNull = %d, \n fRtsControl = %d, \n fAbortOnError = %d\n"), 
              dcb.fErrorChar, 
              dcb.fNull, 
              dcb.fRtsControl,
              dcb.fAbortOnError );
    printf("\r\n\r\n\r\n");
}




int _tmain(int argc, _TCHAR* argv[])
{

   DCB dcb;
   HANDLE hCom;
   BOOL fSuccess;
   TCHAR *pcCommPort = TEXT("COM6"); //  Most systems have a COM1 port

   //  Open a handle to the specified com port.
   hCom = CreateFile( pcCommPort,
                      GENERIC_READ | GENERIC_WRITE,
                      0,      //  must be opened with exclusive-access
                      NULL,   //  default security attributes
                      OPEN_EXISTING, //  must use OPEN_EXISTING
                      0,      //  not overlapped I/O
                      NULL ); //  hTemplate must be NULL for comm devices

   if (hCom == INVALID_HANDLE_VALUE) 
   {
       //  Handle the error.
       printf ("CreateFile failed with error %d.\n", GetLastError());
       return (1);
   }

   //  Initialize the DCB structure.
   SecureZeroMemory(&dcb, sizeof(DCB));
   dcb.DCBlength = sizeof(DCB);

   //  Build on the current configuration by first retrieving all current
   //  settings.
   fSuccess = GetCommState(hCom, &dcb);

   if (!fSuccess) 
   {
      //  Handle the error.
      printf ("GetCommState failed with error %d.\n", GetLastError());
      return (2);
   }

   PrintCommState(dcb);       //  Output to console

   //  Fill in some DCB values and set the com state: 
   //  57,600 bps, 8 data bits, no parity, and 1 stop bit.
   dcb.BaudRate = CBR_9600;     //  baud rate
   dcb.ByteSize = 8;             //  data size, xmit and rcv
   dcb.Parity   = NOPARITY;      //  parity bit
   dcb.StopBits = ONESTOPBIT;    //  stop bit

   fSuccess = SetCommState(hCom, &dcb);

   if (!fSuccess) 
   {
      //  Handle the error.
      printf ("SetCommState failed with error %d.\n", GetLastError());
      return (3);
   }

   //  Get the comm config again.
   fSuccess = GetCommState(hCom, &dcb);

   if (!fSuccess) 
   {
      //  Handle the error.
      printf ("GetCommState failed with error %d.\n", GetLastError());
      return (2);
   }

   PrintCommState(dcb);       //  Output to console

   _tprintf (TEXT("Serial port %s successfully reconfigured.\n"), pcCommPort);

   return (0);
}

运行结果：


 BaudRate = 9600,
 ByteSize = 8,
 Parity = 0,
 StopBits = 0

 fBinary = 1,
 fParity = 0,
 fOutxCtsFlow = 0,
 fDtrControl = 1

 fDsrSensitivity = 0,
 fTXContinueOnXoff = 0,
 fOutX = 0,
 fInX = 0

 fErrorChar = 0,
 fNull = 0,
 fRtsControl = 1,
 fAbortOnError = 0


 BaudRate = 9600,
 ByteSize = 8,
 Parity = 0,
 StopBits = 0

 fBinary = 1,
 fParity = 0,
 fOutxCtsFlow = 0,
 fDtrControl = 1

 fDsrSensitivity = 0,
 fTXContinueOnXoff = 0,
 fOutX = 0,
 fInX = 0

 fErrorChar = 0,
 fNull = 0,
 fRtsControl = 1,
 fAbortOnError = 0

Serial port COM6 successfully reconfigured.
请按任意键继续. . .

hFile [in]

lpDCB [in]

Return value

Remarks

Examples

猜你喜欢