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最终更新
一直都是我们的固件。令人尴尬,但我很高兴我们可以继续前进,并且可以推迟学习Java。我的答案如下。
更新
所以我对此有所放弃。我认为这是API的一个错误,但是我没有时间,资源和技能来深入了解它。我认为存在一些Windows只是中指的硬件。我已经下载了Eclipse,并切换到Java,然后尝试查看它是否有效。如果没有,您会在这里看到我。但是,我绝对愿意解决这个问题,因此,如果任何人有时间或意愿来深入研究这个问题,我都希望看到您的想法。显然,我会不时地回到这里。请确保您在评论中用“@”代表我,以便我们得到提醒。
原始帖子
我知道还有其他一些人在处理这个问题,但是我希望有人可以帮助我。我正在尝试连接到COM port,但是当我尝试使用serialport.Open()
命令时却遇到了I/O异常:
System.IO.IOException: The parameter is incorrect.
at System.IO.Ports.InternalResources.WinIOError(Int32 errorCode, String str)
at System.IO.Ports.InternalResources.WinIOError()
at System.IO.Ports.SerialStream.InitializeDCB(Int32 baudRate, Parity parity, Int32 dataBits, StopBits stopBits, Boolean discardNull)
at System.IO.Ports.SerialStream..ctor(String portName, Int32 baudRate, Parity parity, Int32 dataBits, StopBits stopBits, Int32 readTimeout, Int32 writeTimeout, Handshake handshake, Boolean dtrEnable, Boolean rtsEnable, Boolean discardNull, Byte parityReplace)
at System.IO.Ports.SerialPort.Open()
at *programtitlehere.cs*:line 90
try
{
serialPort1.PortName = "COM5";
serialPort1.Open();
if (serialPort1.IsOpen == true)
{
textBox1.Text = "CONNECTED";
}
else
{
textBox1.Text = "NOT CONNECTED";
}
}
catch (Exception ex)
{
MessageBox.Show("Error: " + ex.ToString(), "ERROR");
}
using System;
using System.IO;
using System.IO.Ports;
using System.Runtime.InteropServices;
using System.Text;
using Microsoft.Win32.SafeHandles;
namespace SerialPortTester
{
public class SerialPortFixer : IDisposable
{
public static void Execute(string portName)
{
using (new SerialPortFixer(portName))
{
}
}
#region IDisposable Members
public void Dispose()
{
if (m_Handle != null)
{
m_Handle.Close();
m_Handle = null;
}
}
#endregion
#region Implementation
private const int DcbFlagAbortOnError = 14;
private const int CommStateRetries = 10;
private SafeFileHandle m_Handle;
private SerialPortFixer(string portName)
{
const int dwFlagsAndAttributes = 0x40000000;
const int dwAccess = unchecked((int) 0xC0000000);
if ((portName == null) || !portName.StartsWith("COM", StringComparison.OrdinalIgnoreCase))
{
throw new ArgumentException("Invalid Serial Port", "portName");
}
SafeFileHandle hFile = CreateFile(@"\\.\" + portName, dwAccess, 0, IntPtr.Zero, 3, dwFlagsAndAttributes,
IntPtr.Zero);
if (hFile.IsInvalid)
{
WinIoError();
}
try
{
int fileType = GetFileType(hFile);
if ((fileType != 2) && (fileType != 0))
{
throw new ArgumentException("Invalid Serial Port", "portName");
}
m_Handle = hFile;
InitializeDcb();
}
catch
{
hFile.Close();
m_Handle = null;
throw;
}
}
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern int FormatMessage(int dwFlags, HandleRef lpSource, int dwMessageId, int dwLanguageId,
StringBuilder lpBuffer, int nSize, IntPtr arguments);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern bool GetCommState(SafeFileHandle hFile, ref Dcb lpDcb);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern bool SetCommState(SafeFileHandle hFile, ref Dcb lpDcb);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern bool ClearCommError(SafeFileHandle hFile, ref int lpErrors, ref Comstat lpStat);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern SafeFileHandle CreateFile(string lpFileName, int dwDesiredAccess, int dwShareMode,
IntPtr securityAttrs, int dwCreationDisposition,
int dwFlagsAndAttributes, IntPtr hTemplateFile);
[DllImport("kernel32.dll", SetLastError = true)]
private static extern int GetFileType(SafeFileHandle hFile);
private void InitializeDcb()
{
Dcb dcb = new Dcb();
GetCommStateNative(ref dcb);
dcb.Flags &= ~(1u << DcbFlagAbortOnError);
SetCommStateNative(ref dcb);
}
private static string GetMessage(int errorCode)
{
StringBuilder lpBuffer = new StringBuilder(0x200);
if (
FormatMessage(0x3200, new HandleRef(null, IntPtr.Zero), errorCode, 0, lpBuffer, lpBuffer.Capacity,
IntPtr.Zero) != 0)
{
return lpBuffer.ToString();
}
return "Unknown Error";
}
private static int MakeHrFromErrorCode(int errorCode)
{
return (int) (0x80070000 | (uint) errorCode);
}
private static void WinIoError()
{
int errorCode = Marshal.GetLastWin32Error();
throw new IOException(GetMessage(errorCode), MakeHrFromErrorCode(errorCode));
}
private void GetCommStateNative(ref Dcb lpDcb)
{
int commErrors = 0;
Comstat comStat = new Comstat();
for (int i = 0; i < CommStateRetries; i++)
{
if (!ClearCommError(m_Handle, ref commErrors, ref comStat))
{
WinIoError();
}
if (GetCommState(m_Handle, ref lpDcb))
{
break;
}
if (i == CommStateRetries - 1)
{
WinIoError();
}
}
}
private void SetCommStateNative(ref Dcb lpDcb)
{
int commErrors = 0;
Comstat comStat = new Comstat();
for (int i = 0; i < CommStateRetries; i++)
{
if (!ClearCommError(m_Handle, ref commErrors, ref comStat))
{
WinIoError();
}
if (SetCommState(m_Handle, ref lpDcb))
{
break;
}
if (i == CommStateRetries - 1)
{
WinIoError();
}
}
}
#region Nested type: COMSTAT
[StructLayout(LayoutKind.Sequential)]
private struct Comstat
{
public readonly uint Flags;
public readonly uint cbInQue;
public readonly uint cbOutQue;
}
#endregion
#region Nested type: DCB
[StructLayout(LayoutKind.Sequential)]
private struct Dcb
{
public readonly uint DCBlength;
public readonly uint BaudRate;
public uint Flags;
public readonly ushort wReserved;
public readonly ushort XonLim;
public readonly ushort XoffLim;
public readonly byte ByteSize;
public readonly byte Parity;
public readonly byte StopBits;
public readonly byte XonChar;
public readonly byte XoffChar;
public readonly byte ErrorChar;
public readonly byte EofChar;
public readonly byte EvtChar;
public readonly ushort wReserved1;
}
#endregion
#endregion
}
internal class Program
{
private static void Main(string[] args)
{
SerialPortFixer.Execute("COM1");
using (SerialPort port = new SerialPort("COM1"))
{
port.Write("test");
}
}
}
}
最佳答案
这来自串行端口驱动程序。对其中一种设置不满意。波特率是一个很好的选择,驱动程序通常最多允许115200。尽管这不是专用CAN总线产品的限制。
解决此问题的最佳方法是使用Sysinternals的Portmon实用程序。您可以看到发送到驱动程序的内容。首先观察终止。这是您的已知工作基准。然后修改SerialPort属性,直到程序发送的初始化命令(与您在PortMon中看到的一样)与Termite匹配为止。只是值,而不是顺序。如果仍然无法解决问题,则将其带到 parking 场,然后用您的汽车翻回几次,然后购买另一个品牌。
更新:它肯定看起来像是一个波特率问题。这是.NET中的问题;它不会像终端仿真器程序那样忽略驱动程序的错误返回代码。实际值无关紧要,因为您正在与仿真串行端口通信。但是,CAN总线速度可能存在问题。汇率是可变的,我不清楚如何协商。在过去,这通常是使用DIP开关完成的,很可能是驾驶员希望您通过波特率设置来指定速度。包装盒或手册中应有相关说明。典型速度为40、250或500 kbit/s。制造商当然会知道。给他们打个电话。
关于c# - 使用serialport.open()时发生I/O异常错误,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14885288/
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