C# SerialPort DSR/DTR 和 CTS/RTS 握手

Question

我正在尝试使用 C#/.NET 的 SerialPort 类与设备通信。

此处描述了与设备交互的文档。

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我正在使用带有 TX/RX 的 NULL 调制解调器电缆，并且交换了所有握手引脚（已验证）。

我希望以下 C# 代码能够正常工作，但我没有从我尝试与之交互的相机得到任何响应（从低到高）。我确信问题出在代码上。该相机可与其他“PC”配合使用。为什么我永远不会在我的代码中让DsrHolding（零调制解调器电缆，因此从相机的 DTR 高）变为 true？

static void Main(string[] args)
{
    var serialPort = new SerialPort("COM5");

    // start the DSR/DTR handshake
    // we are using a null modem cable, so DTR/DSR is switched
    serialPort.DtrEnable = true;
    while (!serialPort.DsrHolding)
    {
        // probally should timeout instead of infinite wait
        Thread.Sleep(10);
        Console.WriteLine("Waiting for the DTR line to go high.");
    }


    // start the RTS/CTS handshake
    // we are using a null modem cable, so RTS/CTS is switched
    serialPort.RtsEnable = true;
    while (!serialPort.CtsHolding)
    {
        // probally should timeout instead of infinite wait
        Thread.Sleep(10);
        Console.WriteLine("Waiting for the RTS line to go high.");
    }

    // read/write
    //serialPort.Write("Some command");
    //var response = serialPort.ReadChar();
    //while (response != stopBit)
    //    response = serialPort.ReadChar();

    // close the connection because we have written/read our data

    // start the DSR/DTR handshake
    // we are using a null modem cable, so DTR/DSR is switched
    serialPort.DtrEnable = false;
    while (serialPort.DsrHolding)
    {
        // probally should timeout instead of infinite wait
        Thread.Sleep(10);
        Console.WriteLine("Waiting for the DTR line to go low.");
    }


    // start the RTS/CTS handshake
    // we are using a null modem cable, so RTS/CTS is switched
    serialPort.RtsEnable = false;
    while (serialPort.CtsHolding)
    {
        // probally should timeout instead of infinite wait
        Thread.Sleep(10);
        Console.WriteLine("Waiting for the RTS line to go low.");
    }
}

Answer 1

您是否尝试过使用直通电缆？相机可能已经处理了需要交叉的针脚。

Answer 2

您的代码中缺少serialPort.Open();