C# virtual serial port timeoutexception on write

Question

i'm having a problem with virtual serial ports in C#: when i call the Write function, it automatically throws a TimeOutException, but the client receives the data.

It only happens with virtual ports (i'm using Free Virtual Serial Ports from HDDSoftware, with a bridge COM12<->COM13). I open COM12 with the Visual Studio and the COM13 with Hercules. The application throws the timeout exception but Hercules receives the message.

It doesn't matter if i set 1000ms or 1000000ms of Read/Write port timeout.

Thanks!!

        using (SerialPort port = new SerialPort("COM13"))
        {
            // configure serial port
            port.BaudRate = 9600;
            port.DataBits = 8;
            port.Parity = Parity.None;
            port.StopBits = StopBits.One;
            port.Open();

            port.ReadTimeout = 10000;

            byte[] buffer = Encoding.ASCII.GetBytes("HELLO WORLD");

            try
            {
                port.Write(buffer, 0, buffer.Length);
            }
            catch(TimeoutException)
            {
                Console.WriteLine("Write timeout");
            }

            Console.WriteLine(DateTime.Now.ToString("HH:mm:ss"));
            try
            {
                byte[] buf = new byte[100];
                port.Read(buf, 0, 1);
            }
            catch(IOException)
            {
                Console.WriteLine("Read timeout");
            }
            Console.WriteLine(DateTime.Now.ToString("HH:mm:ss"));
        }

After a few tests (putting the Write into a try-catch), the Read operation also throws a TimeOutException instantly.

This is what i get when run the test. It is supposed to be: 12:16:06 (Read timeout) 12:16:16

Answer 1

As Hans Passant said, it was a problem with the Virtual COM software. I tried with Virtual Serial Port from Eltima Software and worked fine!