Question

我试图通过串口读取一系列数据。以下是我的测试场景：

我在Windows 10上有一个发送方（POS终端）和一个接收方（dll）。两者都通过RS232电缆（9针）连接。

发件人一次写入16个字节的数据。接收器能够读取数据，每次读取1个字节，循环16次。
发件人一次写入114个字节的数据。接收器能够通过循环114次来读取每次读取1个字节的数据。
发件人一次写入115个字节的数据。接收器能够通过循环115次来读取每次读取1个字节的数据。但最后一个角色丢失了。换句话说，最后一个字符似乎已损坏。

E.g。编写的数据： ABCDEFGHIJKLMNOPQRSTABCDEFGHIJKLMNOPQRSTABCDEFGHIJKLMNOPQRSTABCDEFGHIJKLMNOPQRSTABCDEFGHIJKLMNOPQRSTABCDEFGHIJKLMNO

我能够得到＆＃34; ABCDEFGHIJKLMNOPQRSTABCDEFGHIJKLMNOPQRSTABCDEFGHIJKLMNOPQRSTABCDEFGHIJKLMNOPQRSTABCDEFGHIJKLMNOPQRSTABCDEFGHIJKLMN ＆＃34;正确。但最后一个字符＆＃39; O＆＃39; 已损坏。而是代替最后一个字符读取的数据是（ASCII值）205,255,234等。在多次读取尝试期间数据不一致。

任何人都可以对此有所了解吗？如果我遗失某些东西，有人可以指导我吗？

我在本项目中提到了这篇文章：Serial Port Communication Below is the code snippet:

//Port opening.
HANDLE hPortDailUp = CreateFile(portfinal,
            GENERIC_READ | GENERIC_WRITE,
            0,
            NULL,
            OPEN_ALWAYS,
            0,
            NULL);

//Setting COM timeouts.
SetCommMask(hPortDailUp, 0);
SetupComm(hPortDailUp, 2048, 2048);
GetCommTimeouts (hPortDailUp, &commTimeOuts);
commTimeOuts.ReadIntervalTimeout = 100;
commTimeOuts.ReadTotalTimeoutMultiplier = 70;
commTimeOuts.ReadTotalTimeoutConstant = 1000; //1000
commTimeOuts.WriteTotalTimeoutMultiplier = 0;
commTimeOuts.WriteTotalTimeoutConstant = 0;
SetCommTimeouts(hPortDailUp, &commTimeOuts);

//Setting port configuration.
DCB PortDCB;
PortDCB.DCBlength = sizeof(DCB);

PortDCB.BaudRate = BaudRate;
PortDCB.ByteSize = 8;
PortDCB.Parity = NOPARITY;
PortDCB.StopBits = ONESTOPBIT;
PortDCB.fOutxCtsFlow = RTS_CONTROL_DISABLE;
PortDCB.fRtsControl = RTS_CONTROL_DISABLE;
SetCommState(hPortDailUp, &PortDCB)

//Reading data from serial port.
unsigned char tempRecvBuf[3001] = {'\0'};
ReadFile(hPortDailUp, tempRecvBuf + nBytesRead, 1, &TempLen, NULL);

//PortDCB Value at runtime.
PortDCB {DCBlength=28 BaudRate=115200 fBinary=1 ...}    _DCB
    DCBlength           28          unsigned long
    BaudRate            115200      unsigned long
    fBinary             1           unsigned long
    fParity             0           unsigned long
    fOutxCtsFlow        0           unsigned long
    fOutxDsrFlow        0           unsigned long
    fDtrControl         1           unsigned long
    fDsrSensitivity     0           unsigned long
    fTXContinueOnXoff   0           unsigned long
    fOutX               0           unsigned long
    fInX                0           unsigned long
    fErrorChar          0           unsigned long
    fNull               0           unsigned long
    fRtsControl         0           unsigned long
    fAbortOnError       0           unsigned long
    fDummy2             0           unsigned long
    wReserved           0           unsigned short
    XonLim              2048        unsigned short
    XoffLim             512         unsigned short
    ByteSize            8 '\b'      unsigned char
    Parity              0 '\0'      unsigned char
    StopBits            0 '\0'      unsigned char
    XonChar             17 '\x11'   char
    XoffChar            19 '\x13'   char
    ErrorChar           0 '\0'      char
    EofChar             0 '\0'      char
    EvtChar             0 '\0'      char
    wReserved1          0           unsigned short

Answer 1

你的循环可能没有足够快地读出字符，所以到了第115次，一个新角色已经覆盖了最后一个被太晚读出的角色。要对此进行测试，您可以在发送器端的字符之间添加非常短的延迟，然后查看接收器的行为是否不同。

通过串口（RS232）丢失数据

1 个答案: